Veterinary Technician's Daily Reference Guide: Canine and Feline

Veterinary Technician’s Daily Reference Guide: Canine and Feline Second Edition

Veterinary Technician’s Daily Reference Guide: Canine and Feline Second Edition Candyce M. Jack, LVT Sequim, Washington

Patricia M. Watson, LVT Redmond, Washington

Mark S. Donovan, DVM Consulting Editor Seattle, Washington

First Edition first published 2003 Second Edition first published 2008 © 2008, Candyce M. Jack and Patricia M. Watson Blackwell Publishing was acquired by John Wiley & Sons in February 2007. Blackwell’s publishing program has been merged with Wiley’s global Scientific, Technical, and Medical business to form Wiley-Blackwell. Editorial Office 2121 State Avenue, Ames, Iowa 50014-8300, USA For details of our global editorial offices, for customer services, and for information about how to apply for permission to reuse the copyright material in this book, please see our website at www.wiley.com/wiley-blackwell. Authorization to photocopy items for internal or personal use, or the internal or personal use of specific clients, is granted by Blackwell Publishing, provided that the base fee is paid directly to the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923. For those organizations that have been granted a photocopy license by CCC, a separate system of payments has been arranged. The fee codes for users of the Transactional Reporting Service are ISBN-13: 978-0-8138-1204-5/2008. Designations used by companies to distinguish their products are often claimed as trademarks. All brand names and product names used in this book are trade names, service marks, trademarks or registered trademarks of their respective owners. The publisher is not associated with any product or vendor mentioned in this book. This publication is designed to provide accurate and authoritative information in regard to the subject matter covered. It is sold on the understanding that the publisher is not engaged in rendering professional services. If professional advice or other expert assistance is required, the services of a competent professional should be sought. Library of Congress Cataloguing-in-Publication Data Jack, Candyce M. Veterinary technician’s daily reference guide: canine and feline / Candyce M. Jack, Patricia M. Watson; consulting editor, Mark S. Donovan. – 2nd ed. p. ; cm. Rev. ed. of: Veterinary technician’s daily reference guide: canine and feline / Candyce M. Jack, Patricia M. Watson; consulting editor, Mark S. Donovan. C2003. Includes bibliographical references and index. ISBN 978-0-8183-1204-5 (alk, paper) 1. Veterinary medicine–Handbooks, manuals, etc. I. Watson, Patricia M. II. Jack, Candyce M. Veterinary technician’s daily reference guide. III. Title. [DNLM: 1. Veterinary Medicine–methods–Handbooks. 2. Animal Technicians– Handbooks. 3. Cat Diseases–Handbooks. 4. Dog Diseases–Handbooks. SF 748 J12v 2008] SF748.J33 2008 636.089–dc22 2007050954 A catalogue record for this book is available from the U.S. Library of Congress. Set in Berling-Roman by SNP Best-set Typesetter Ltd Printed in Singapore by Markono Print Media Pte Ltd 1 2008

This book is dedicated to all the licensed veterinary technicians who are doing their best for the advancement of the field and devoting themselves to providing the best possible care to their animal patients. A special thanks to our medical editor, Dr. Mark Donovan, for his commitment to our goal and his perseverance to ensure the book presented advanced and accurate information. Patricia Special thanks for family, co-workers, and friends who are consistently supporting me to new levels of learning and opportunity. Each of you and your pets are a part of this book and I am grateful for your constant support. Thanks to my coauthor, whose insight, energy, dedication to the veterinary field, and perseverance has made this second edition a reality. And finally, I dedicate this book in special remembrance of my beloved Einstein (1991–2006), whose teeth are immortalized within the pages of this book. Candyce With heartfelt gratitude, I thank Dede for her patience and friendship, Linda for her continuous support of my endeavors, Megan for teaching me “you can’t push the river,” and, most important, my incredibly supportive family for the sacrifices they have made to allow me to complete this project.

Table of Contents Figure List Preface Acknowledgments Contributors

xvii xxi xxiii xxiii

Section One: Anatomy

3

Chapter 1:

5

Anatomy Anatomy Overall Musculature Skeletal Internal Organs Circulatory System Nervous System Urogenital Eye Ear

6 6 6 7 8 9 10 11 13 13

Section Two: Preventative Care

15

Chapter 2:

Preventative Care and Vaccinations

17

Physical Examinations Preliminary Examination Physical Examination Pediatric Physical Examination Normal Parturition Care and Feeding of Orphaned Puppies and Kittens Geriatric Physical Examination Cardiac Examination Pulmonary Examination Abdominal Examination Otoscopic Examination Regional Lymph Node Examination Neurologic Examination Orthopedic Examination Vaccinations Guidelines to Follow When Vaccinating an Animal

18 19 20 23 26 27 28 30 32 33 33 34 34 36 37 37

Chapter 3:

Canine Transmissible Diseases Coronavirus, Distemper Hepatitis, Infectious Tracheobronchitis Leptospirosis, Lyme Disease Parvovirus, Rabies Canine Vaccination Protocol Feline Transmissible Diseases Feline Calicivirus Feline Infectious Peritonitis Feline Panleukopenia Virus, Feline Immunodeficiency Virus Feline Leukemia Virus, Feline Rhinotracheitis Virus Feline Vaccination Protocol Animal Care Client Education: Home Dental Care Grooming Bathing Nail Trimming Anal Sac Expression Ear Cleaning and Flushing

38 38 39 41 42 44 44 44 46 47

Nutrition

57

General Nutrition Daily Caloric Requirement Worksheet for a Healthy Animal General Life Stage Feeding Guidelines Body Condition Scoring System Disease Nutritional Requirements Obesity Management

58

49 51 51 52 53 53 54 54 55

59 60 62 64 68

Section Three: Diagnostic Skills

69

Chapter 4:

Laboratory

71

Blood Chemistries Blood Collection, Handling, Storage, and Transport Tips

74 74 vii

Blood Collection Tubes Blood Chemistries Bone Marrow Evaluation Bone Marrow Collection, Handling, Storage, and Transport Tips Supplies for Bone Marrow Collection Smear Techniques Evaluation Bone Marrow Evaluation Cell Type Identification Interpretation Cytology Cytology Collection, Handling, Storage, and Transport Tips Collection Techniques FNB Needle and Syringe Selection Smear Techniques Evaluation Cytologic Criteria of Malignancy Figure 4.4: Cytologic Criteria of Malignancy Specific Tumor Cells Interpretation Fecal Cytology Vaginal Cytology Classifying Vaginal Cells Staging the Estrus Cycle Function Tests Hematology Complete Blood Count Hemacytometer Use Calculating a Differential Evaluation RBC Alterations and Morphology WBC Morphology WBC Alterations WBC Left Shift Platelet Morphology Platelet Alterations Coagulation Tests Coagulation Screening Coagulation Tests Blood Transfusions Crossmatching viii

TABLE OF CONTENTS

75 76 83

Blood Typing Immunology and Serology Tests Microbiology Microbiology Collection, Handling, Storage, and Transport Tips Collection Techniques Specimen Storage Most Commonly Used Culture Media Culture Media Inoculation and Incubation Evaluation of Culture Growth Staining Solutions and Procedures Staining Problems Bacteria Identification Fungi Identification Parasitology Fecal Collection, Handling, Storage, and Transport Tips Endoparasite Examination Methods Fecal Flotation Solutions Blood Parasite Examination Methods Ectoparasite Examination Methods Figure 4.35: Relative Size of Parasite Eggs Endoparasites Ectoparasites Urinalysis Urine Collection, Handling, Storage, and Transport Tips Urine Examination/Urinalysis Gross Examination Preparation Chemistry Strip Examination Sediment Examination Reporting of Bacteria and Sperm Sediment Examination Urine Artifacts

83 84 84 85 85 86 88 88 88 88 89 90 91 92 93 94 95 96 97 97 98 98 104 105 108 108 108 108 112 113 114 115 115 115 115 116 119 119

Chapter 5:

120 120 122 122 123 124 125 126 127 127 130 130 133 134 134 134 137 138 139 139 139 145 147 147 147 148 149 149 150 151 151 155

Imaging

157

Radiology Radiographic Equipment Radiographic Exposure and Image Factors Radiographic Technique Chart Example 1: Veterinary X-Ray Technique Guide

159 160 161 161 162

Example 2: Veterinary X-Ray Technique Chart Evaluating Radiograph Technique Exposure Evaluation Density Evaluation Scale of Contrast Evaluation Radiographic Alterations Radiographic Artifacts Radiographic Positioning Directional Terms Positional Terms Soft Tissue Positioning Thorax Abdomen and Pharynx Head Positioning Skull Zygomatic Arch Tympanic Bullae Temporomandibular Joint Nasal Cavities and Sinuses Nasal Cavities and Sinuses (continued) Spine Positioning Cervical Thoracic–Lumbar Sacrum–Caudal Shoulder and Forelimb Positioning Scapula–Shoulder Humerus Elbow Radius/Ulna and Carpus Metacarpus/Phalanges Pelvis and Hindlimb Positioning Pelvis Femur, Stifles, and Tibia/Fibula Tarsus and Metatarsals Radiographic Contrast Studies Types of Contrast Media Fistula Contrast Studies Fistulography Abdominal Contrast Studies Peritoneography Gastrointestinal Tract Contrast Studies Esophagography and Gastrography Upper and Lower Gastrointestinal Study

163 164 164 164 164 166 167 167 168 168 169 169 169 170 170 171 172 172 173 173 174 174 175 175 176 176 176 177 178 178 179 179 180 181 181 182 183 183 183 183 184 184 185

Head Contrast Studies Dacryocystorhinography, Rhinography, and Sialography Spinal and Joint Contrast Studies Myelography and Epidurography Discography and Arthrography Urethra Contrast Studies Urethrography, Canine Urethrography, Feline Vaginal Contrast Studies Vaginography Urinary Tract Contrast Studies Cystography Cystography (continued) Additional Imaging Techniques Computer Tomography and Echocardiography Fluoroscopy Magnetic Resonance Imaging and Nuclear Medicine Ultrasonography Basic Scanning Technique Sites for Ultrasound Scanning

187 187 188 188 189 190 190 191 192 192 193 193 194 195 195 196 196 197 198 198

General Medicine

201

Cardiopulmonary Asthma and Brachycephalic Airway Syndrome Bronchitis and Cardiomyopathy, Hypertrophic Cardiomyopathy, Dilated Cardiomyopathy, Restrictive and Congenital Heart Disease Endocardiosis and Heartworm Disease Congestive Heart Failure Hypertension and Myocarditis Pneumonia and Pleural Effusion Rhinitis/Sinusitis and Tracheal Collapse Dermatology Acne Acral Lick Dermatitis, Atopy, and Flea Allergy Dermatitis Food Hypersensitivity and Otitis Externa Pyoderma

204 204 205 208

Color Plate Chapter 6:

TABLE OF CONTENTS

210 211 214 215 217 219 220 220 222 224 225 ix

Endocrinology and Reproduction Abortion and Diabetes Insipidus Diabetes Mellitus Dystocia and Eclampsia Hyperadrenocorticism and Hyperparathyroidism Hyperthyroidism and Hypoadrenocorticism Hypoparathyroidism, Hypothyroidism, and Mastitis Pregnancy and Pyometra Gastroenterology Anal Sac Disease, Cholangitis, and Cholangiohepatitis Constipation and Megacolon Diarrhea Exocrine Pancreatic Insufficiency and Gastric Dilatation-Volvulus Hepatic Disease/Failure Hepatic Lipidosis and Inflammatory Bowel Disease Megaesophagus Pancreatitis and Peritonitis Protein-Losing Enteropathy and Vomiting Hematology Anemia and Disseminated Intravascular Coagulation Thrombocytopenia and von Willebrand’s Disease Infectious Diseases Brucellosis and Erhlichiosis Rocky Mountain Spotted Fever and Salmon Poisoning Tetanus and Toxoplasmosis Musculoskeletal Arthritis Cruciate Disease and Hip Dysplasia Osteochondrosis and Osteomyelitis Patellar Luxation and Panosteitis Neurology Encephalitis and Epilepsy Intervertebral Disc Disease and Meningitis Myasthenia Gravis and Myelopathy Vestibular Disease and Wobbler Syndrome Oncology Neoplasia Histiocytoma, Mammary Gland Neoplasia, and Mast Cell Tumor Various Neoplasias x

TABLE OF CONTENTS

227 227 228 230 231 233 235 237 238

Ophthalmology Anterior Uveitis and Cataracts Conjunctivitis and Entropion Cilia Disorders and Glaucoma Keratitis and Keratoconjunctivitis Sicca Lens Luxation and Prolapsed Gland of the Third Eyelid Urology Cystic Calculi, Feline Lower Urinary Tract Disease, and Pyelonephritis Renal Failure Urinary Tract Obstruction and Urinary Tract Infection

238 240 241 243 245 246 248 249 251 253 253 254 256 256 258 259 261 261 263 264 266 267 267 269 271 272 273 273 275 277

Chapter 7:

284 284 285 287 288 290 292 292 294 296

Emergency Medicine

299

Emergency Medicine Emergency Supplies Telephone Assessment and Emergency Transportation Recommendations Inducing Vomiting At-Home Triage Primary Survey Hemostasis Cardiopulmonary Cerebrovascular Resuscitation (CPCR) Secondary Survey Shock Cardiovascular Emergencies Environmental Emergencies Gastrointestinal Emergencies Hematologic Emergencies Metabolic and Endocrine Emergencies Neonatal Emergencies Neonatal Resuscitation Post-Cesarean Neurologic Emergencies Ophthalmic Emergencies Renal and Urinary Emergencies Reproductive and Genital Emergencies Respiratory Emergencies Toxicologic Emergencies Toxins Trauma Emergencies

301 301 304 305 306 306 307 308 309 310 312 313 314 315 316 317 317 318 319 320 321 322 323 324 326

Section Four: Patient Care Skills

327

Chapter 8:

Patient Care

329

Patient Monitoring Blood Pressure Blood Pressure Procedure Blood Pressure Results Central Venous Pressure Blood Gas Analysis Blood Gas Analysis Arterial Blood Gas Interpretation Acid-Base Disturbances Electrocardiogram ECG Procedure ECG Leads ECG Interpretation Figure 8.1 Normal Canine Electrocardiogram Heart Rate Calculation Common Rhythm Abnormalities Figure 8.2 Atrial Premature Contraction/Complex Figure 8.3 ST-Segment Elevation Figure 8.4 Ventricular Premature Contraction/ Complex ECG Problems and Artifacts Heat Administration Recumbent Patient Care Drug Administration Injections Intravenous Catheter Placement Peripheral and Jugular Arterial and Intraosseous Monitoring and Maintenance Chemotherapy Administration Toxicity Client Education: Monitoring Chemotherapy Response Insulin Therapy Client Education: Insulin Administration Client Education: Monitoring Insulin Response Client Education: Monitoring for Hypoglycemia Fluid Therapy Hydration Assessment

332 332 332 333 334 335 335 337 337 338 338 339 340 341 342 343 344 344 344 345 346 347 348 348 349 349 350 351 352 352 353 356 357 357 358 359 359 360

Chapter 9:

Calculating Fluid Requirements Routes of Fluid Administration Commonly Used Fluids Fluid Additives Calculating Drip Rates Monitoring Fluid Therapy Blood Transfusions Blood Types Blood Collection Blood Products Blood Administration Blood Transfusion Reactions Oxygen Therapy Oxygen Administration Routes of Oxygen Administration Oxygen Hood and Nasal Catheter Transtracheal Catheter and Tracheostomy

361 362 363 365 365 366 367 368 369 371 373 374 375 375 376 376 377

Pain Management

379

Pain Management Pain Assessment Pain Scales Instructions for Using the CSU Acute Pain Scale Pain Levels Associated With Surgical Procedures, Injuries, and Illness Behaviors Suggesting Pain and Anxiety Nondrug Approach to Decrease Pain and Anxiety Pain Management Drugs Pain Management Techniques Constant Rate Infusions Setting Up a Morphine/Lidocaine/Ketamine Constant Rate Infusion

380 381 381

Chapter 10: Wound Care

382 383 384 386 386 392 392 393

395

Wound Treatment and Bandaging Wound Healing Process Classification of Wounds Factors Affecting the Healing Process Wound Care TABLE OF CONTENTS

396 396 397 398 399 xi

Wound Cleaning Solutions Topical Wound Medications Wound Bandaging Bandage Care Bandaging Basic Bandage Robert Jones Bandage Chest/Abdominal Bandage Distal Limb Splint Casts Ehmer Sling 90–90 Flexion Velpeau Sling Hobbles Chapter 11: Parenteral Nutrition Nutritional Support Tips on Encouraging Oral Nutrition Enteral Nutrition Coax Feeding and Orogastric Tube Nasoesophageal/Nasogastric Tube Esophagostomy Tube Gastrotomy Tube Without Gastropexy Gastrotomy Tube With Gastropexy Jejunostomy Tube Enteral Nutrition Administration Parenteral Nutrition Parenteral Nutrition Parenteral Nutrition Administration Worksheet for Calculating Total Parenteral Nutrition (TPN) Worksheet for Calculating Peripheral or Partial Parenteral Nutrition (PPN)

Chapter 12: Medical Procedures Gastrointestinal Procedures Stomach Tube and Gastric Lavage Gastrointestinal Tube Placement Verification Abdominocentesis and Diagnostic Peritoneal Lavage Enema, Warm Water xii

TABLE OF CONTENTS

401 402 403 404 405 405 406 407 408 408 409 410 410 411 413 414 414 414 414 415 417 418 419 420 421 422 423 424 425 426

427 428 428 429 429 430

Ophthalmic Procedures Schirmer Tear Test, Fluorescein Sodium Stain, and Tonometry Respiratory Procedures Thoracocentesis and Thoracostomy Tube Placement Nebulization, Coupage, and Metered-Dose Inhalers Urogenital Procedures Urine Collection Urine Collection Devices Urinary Catheterization Urinary Catheter Maintenance

430 430 431 431 432 434 434 435 435 436

Section Five: Anesthesia and Anesthetic Procedures

437

Chapter 13: Anesthesia

439

Guidelines for Safe Anesthesia Preanesthetic Preanesthetic Evaluation Case-Based Anesthesia Preanesthetic Drugs Anesthesia Anesthetic Administration Anesthetic Machine Machine Setup Anesthetic Breathing Systems Anesthetic Administration General Anesthesia Induction Endotracheal Intubation Figure 13.1 Endotracheal Intubation Endotracheal Complications Perioperative Patient Care Intermittent Positive-Pressure Ventilation (IPPV) Anesthetic Monitoring Stages of Anesthesia Anesthesia Monitoring Postanesthesia Recovery Postanesthetic Monitoring Local and Regional Anesthesia Ventilation

441 442 442 444 451 451 451 451 451 452 453 453 454 455 456 456 456 458 458 458 460 466 466 467 470 474

General Information Administration Anesthetic Drugs Preanesthetic Drugs Anticholinergic Drugs Atropine and Glycopyrrolate Phenothiazines Acepromazine Maleate Benzodiazepines Diazepam and Midazolam α2-Agonists Xylazine and Medetomidine Opioids Butorphanol and Buprenorphine Fentanyl and Hydromorphone Morphine Sulfate and Oxymorphone HCl Injectable Induction Anesthetics Barbituates Thiobarbituates and Methylated Barbituates Cyclohexamines Ketamine and Tiletamine Propofol Propofol (continued) Etomidate Etomidate (continued) Inhalant Anesthetics Halothane and Isoflurane Sevoflurane Chapter 14: Dentistry Dentistry Anatomy Figure 14.1: Dentition: Canine and Feline Figure 14.2: Cross Section of a Triple-Rooted Tooth Figure 14.3: Skeletal Structure: Canine and Feline Figure 14.4: Cross Section of Facial Structures: Canine and Feline Dental Instruments and Equipment Hand-held Instruments Figure 14.5: Hand-held Non-mechanical Dental Instruments Instrument Maintenance

474 475 477 477 477 478 478 479 480 480 481 482 484 485 486 487 488 488 489 490 491 492 492 493 494 494 495 496 497 499 499 499 500 500 501 501 501 502 502

Sharpening Technique Mechanical Instruments Dental Prophylaxis Dental Cleaning Procedure Dental Charting Figure 14.6: Sample of Patient’s Dental Health Chart Common Dental Disorders Anatomical Disorders Pathologic Disorders Dental Radiology Equipment Technique Chart Radiographic Film Radiographic Techniques Radiographic Positioning Extractions General Extraction Procedures Local Dental Nerve Blocks Chapter 15: Surgery

503 503 504 504 506 509 510 510 511 512 512 512 513 513 514 517 517 518 521

Instrument Packs Preoperative Protocol Surgical Procedures Abdominal Surgery Abdominal Hernia, Anal Sacculectomy, and Colotomy Enterotomy, Gastric-Dilatation Volvulus, and Gastrotomy Intestinal Resection and Anastomosis and Hepatectomy Aural Surgery Aural Hematoma and Lateral Ear Canal Resection Integumentary Surgery Abscess and Laceration Mass Removal and Onychectomy Neurologic Surgery Disc Fenestration, Dorsal Laminectomy, and Hemilaminectomy Ophthalmic Surgery Cataracts, Ectropion, and Entropion Conjunctival Flap and Enucleation TABLE OF CONTENTS

523 524 525 525 526 528 529 530 530 531 532 533 534 535 536 537 538 xiii

Glaucoma and Nictitating Membrane Flap Replacement Prolapse of the Gland of the Third Eyelid and Traumatic Proptosis Orthopedic Surgery Cranial Cruciate Ligament Repair, Femoral Head Ostectomy, and Fracture Repair Patellar Luxation, Total Hip Replacement, and Triple Pelvic Osteotomy Reproductive Tract Surgery Cesarean Section, Orchiectomy, and Ovariohysterectomy Postoperative Care of Neonates and Dam Thoracic Surgery Diaphragmatic Hernia, Laryngeal Paralysis, and Sternotomy Thoracotomy and Tracheal Collapse Urogenital Tract Surgery Cystotomy and Urethrostomy, Perineal Urethrostomy, Scrotal, and Urethrostomy, Prescrotal Suture Techniques Suture Patterns Knot Tying Postoperative Care Protocol Standard Postoperative Care Instructions Preventing Self-Trauma Alternative Surgical Options Endoscopy: Flexible Gastrointestinal and Rigid Laser Surgery Radiation Therapy: Teletherapy, Brachytherapy and Systemic Therapy Temperature Therapy: Hyperthermia and Cryosurgery

538 539 539 540 541 542 542 544 544 545 546 547 547 548 548 548 549 550 550 550 551 551 552 553 554

Section Six: Complementary and Alternative Veterinary Medicine and Pharmacology

555

Chapter 16: Complementary and Alternative Veterinary Medicine

557

Complementary and Alternative Veterinary Medicine (CAVM) Physical Therapy and Rehabilitation Traditional Chinese Medicine

558 558 562

xiv

TABLE OF CONTENTS

Ayurveda and Chiropractic Flower Essences and Homeopathy Laser Therapy Magnetic Field Therapy Western Herbal Medicine Chapter 17: Pharmacology Pharmacology Basic Calculations Drug Cross-Reference Antifungal Drugs Anti-infective Drugs Aminoglycosides, Cephalosporins, and Chloramphenicol Fluoroquinolones, Lincosamides, and Metronidazole Penicillin, Sulfonamides, and Tetracyclines Antiparasitic Drugs Antinematodals Antinematodals (continued) Anticestodals Ectoparasitics Ectoparasitics (continued) Cancer/Chemotherapy Drugs Alkylating Agents Anthracycline Antibiotics Antimetabolites Enzyme, Immunomodulating, Synthetic Hormone, and Vinca Alkaloid Cardiovascular Drugs Antianemics Antiarrhythmics Anticoagulants and Calcium Supplements Contractility Enhancers and Positive Inotropic Agents Diuretics Vasodilators Dermatologic Drugs Antiseborrheics Antipruritics/Antihistamines Gastrointestinal Drugs Antidiarrheals Antiemetics

563 564 565 565 566 567 570 570 571 574 575 575 576 577 578 578 579 579 580 580 581 581 582 583 584 585 585 586 587 588 589 590 591 591 591 592 592 593

Antiulcer Agents Emetics Enzyme, Laxatives, and Lubricants Protectants and Stool Softener Hepatic Drugs Supplements Metabolic Drugs Adrenal Cortex Pancreatic Pancreatic (continued) Parathyroid and Thyroid Musculoskeletal Drugs Anti-inflammatory Drugs Nonsteroidal Anti-inflammatory Drugs Nonsteroidal Anti-inflammatory Drugs (continued) Nonsteroidal Anti-inflammatory Drugs (continued) Protectant, Muscle Relaxer, and Supplement Neurologic Drugs Appetite Stimulator and Cholinergics Autonomic Nervous System: Adrenergic Agents: Alpha Stimulators Central Nervous System: Anticonvulsants Euthanasia Agents and Muscle Relaxers Analgesics Analgesic/Anticonvulsant, NMDA Antagonist, and Narcotic Agonist Analgesic: Opioids Analgesic: Opioids (continued) Behavioral: Antidepressants Ophthalmic Drugs Adrenergic Agonist, Carbonic Anhydrase Inhibitors, and Immunosuppressant Miotics, Mydriatics/Cycloplegics, Topical Anesthetics, and Stains

594 595 596 597 598 598 599 599 600 601 601 602 602 603 604 605 605 606 606 607 607 608 609 610 611 612 613 613 613

Otic Drugs Topical Anti-infectives Renal/Urinary Drugs Acidifers, Adrenergic Agent. and Alkalinizing Agent Alpha-Adrenergic Agent, Antibacterial/Acidifer, Anabolic Steroid, and Cholinergic Enzyme Inhibitor and Tricyclic Antidepressant Reproductive System Drugs Androgens, Estrogens, and Gonadotrpins Oxytocin, Progestins, and Prostaglandin Respiratory Drugs Antitussives Bronchodilators and Mucolytics Stimulants Toxicologic Drugs Chelating Drugs and Synthetic Alcohol Dehydrogenase Inhibitor Appendix

615 615 616 616 617 618 619 619 620 621 621 622 623 624 624 625 625 625 626 626 627 627 628

Metric Units Weights Liquid Measure Length Kilograms to Body Surface Area Temperature Conversion Disinfectants Glossary Abbreviations Bibliography Index

631 647 651 661

614

TABLE OF CONTENTS

xv

Figure List Chapter 1: Anatomy Figure 1.1 Overall Figure 1.2 Regional Lymph Nodes Figure 1.3 Musculature: Lateral View Figure 1.4 Skeletal: Lateral View Figure 1.5 Skeletal: Dorsal View Figure 1.6 Internal Organs: Left Lateral View Figure 1.7 Internal Organs: Right Lateral View Figure 1.8 Internal Organs: Ventral View Figure 1.9 Circulation: Dorsal View of Heart Figure 1.10 Circulation: Internal View of Heart Figure 1.11 Circulation: Heart Valves Figure 1.12 Circulatory: Lateral View Figure 1.13 Nervous System: Lateral View of Brain Figure 1.14 Nervous System: Lateral View Figure 1.15 Urogenital: Ventral View, Female Figure 1.16 Urogenital: Ventral View, Male Figure 1.17 Urogenital: Lateral View, Male Figure 1.18 Eye Figure 1.19 Ear

6 6 6 7 7 8 8 8 9 9 10 10 10 11 11 12 12 13 13

Chapter 3: Nutrition Table 3.2 Body Condition Score

61

Chapter 4: Laboratory Figure 4.4 Cytologic Criteria of Malignancy Figure 4.35 Relative Size of Parasite Eggs

93 139

Chapter 5: Imaging Table 5.4 Scale of Contrast Evaluation Table 5.7 Directional terms

165 168

Chapter 8: Patient Care Figure 8.1 Normal Canine Electrocardiogram Figure 8.2 Atrial Premature Contraction/Complex Figure 8.3 ST-Segment Elevation Figure 8.4 Ventricular Premature Contraction/Complex

341 344 344 344

Chapter 10: Wound Care Box 10.3 Basic Bandage Box 10.4 Robert Jones Bandage Box 10.5 Chest/Abdominal Bandage Box 10.6 Distal Limb Splint Box 10.7 Casts Box 10.8 Ehmer Sling Box 10.9 90–90 Flexion Box 10.10 Velpeau Sling Box 10.11 Hobbles

405 406 407 408 408 409 410 410 411

Chapter 13: Anesthesia Figure 13.1 Endotracheal Intubation

455

Chapter 14: Dentistry Figure 14.1 Dentition: Canine and Feline Figure 14.2 Cross Section of a Triple-Rooted Tooth Figure 14.3 Skeletal Structure: Canine and Feline Figure 14.4 Cross Section of Facial Structures: Canine and Feline Figure 14.5 Hand-held Nonmechanical Dental Instruments Figure 14.6 Sample of a Patient’s Dental Health Chart Table 14.10 Radiographic Positioning

499 500 500 501 502 509 514

Color Plate Anatomy Figure 1.6 Internal Organs: Left Lateral View Figure 1.7 Internal Organs: Right Lateral View Figure 1.8 Internal Organs: Ventral View Figure 1.9 Circulatory: Dorsal View of Heart Figure 1.10 Circulatory: Internal View of Heart Figure 1.12 Circulatory: Lateral View Figure 1.14 Nervous System: Lateral View Bone Marrow Figure 4.1 Canine Bone Marrow Figure 4.2 Canine Bone Marrow Figure 4.3 Maturation Stages of Megakaryocytes Tumor Cytology Figure 4.5 Histiocytoma

CP-1 CP-1 CP-1 CP-1 CP-2 CP-2 CP-2 CP-3 CP-3 CP-3 CP-4 xvii

Figure 4.6 Lymphoma Figure 4.7 Mast Cell Tumor Fecal Cytology Figure 4.8 Clostridium Figure 4.9 Giardia Figure 4.10 Campylobacter Figure 4.11 Spirochetes Figure 4.12 Yeast Hematology Figure 4.13 Canine Blood Smear Figure 4.14 Canine Distemper Figure 4.15 Feline Blood Smear Figure 4.16 Canine Blood Smear Figure 4.17 Feline Blood Smear Figure 4.18 Feline Blood Smear Figure 4.19 Canine Blood Smear Figure 4.20 Canine Blood Smear Figure 4.21 Babesia canis Figure 4.22 Cytauxoon felis Figure 4.23 Neutrophils Figure 4.24 Lymphocytes Figure 4.25 Monocytes Figure 4.26 Canine Blood Smear Figure 4.27 Eosinophils Figure 4.28 Basophils Figure 4.29 Canine Blood Smear Figure 4.30 Feline Blood Smear Figure 4.31 Canine Blood Smear Figure 4.32 Canine Blood Smear Figure 4.33 Blood Smear Ear Cytology Figure 4.34 Malessezia Endoparasites Figure 4.36 Ancylostoma caninum Figure 4.37 Ancylostoma tubaeforme Figure 4.38 Crytosporidium Figure 4.39 Didylidium caninum Figure 4.40 Dirofilaria immitis Figure 4.41 Echinococcus granulosus Figure 4.42 Giardia Figure 4.43 Isospora spp. Figure 4.44 Taenia spp. Figure 4.45 Toxocara canis xviii

FIGURE LIST

CP-4 CP-4 CP-4 CP-5 CP-5 CP-5 CP-5 CP-6 CP-6 CP-6 CP-6 CP-7 CP-7 CP-7 CP-7 CP-8 CP-8 CP-8 CP-8 CP-9 CP-9 CP-9 CP-9 CP-10 CP-10 CP-10 CP-10 CP-11 CP-11 CP-11 CP-11 CP-12 CP-12 CP-12 CP-12 CP-12 CP-12 CP-12 CP-12

Figure 4.46 Figure 4.47 Figure 4.48 Figure 4.49 Ectoparasites Figure 4.50 Figure 4.51 Figure 4.52 Figure 4.53 Figure 4.54 Figure 4.55 Figure 4.56 Figure 4.57 Figure 4.58 Urinalysis Figure 4.59 Figure 4.60 Figure 4.61 Figure 4.62 Figure 4.63 Figure 4.64 Figure 4.65 Figure 4.66 Figure 4.67 Figure 4.68 Figure 4.69 Figure 4.70 Figure 4.71 Figure 4.72 Figure 4.73 Figure 4.74 Figure 4.75 Figure 4.76 Figure 4.77 Figure 4.78 Figure 4.79 Figure 4.80 Figure 4.81 Figure 4.82 Figure 4.83 Figure 4.84 Figure 4.85 Figure 4.86

Toxocara cati Toxoplasma gondii Trichuris vulpis Uncinaria stenocephala

CP-13 CP-13 CP-13 CP-13

Cheyletiella Ctenocephalides canis Demodex canis Dermacentor variabilis Linognathus setosus Otodectes cynotis Rhipicehpalus sanguineus Sarcoptes scabiei canis Trichodectes canis

CP-13 CP-13 CP-13 CP-13 CP-14 CP-14 CP-14 CP-14 CP-15

Bacteria Bacteria Bacteria White Blood Cells White Blood Cells Epithelial Cells Epithelial Cast Fatty Cast Granular Cast Hyaline Cast Red Blood Cell Cast White Blood Cell Cast Waxy Cast Amorphous Phosphate Crystals Amorphous Urate Crystals Amorphous Biurate Crystals Bilirubin Crystals Calcium Carbonate Crystals Calcium Oxalate Dihydrate Crystals Cystine Crystals Leucine Crystals Sulfonamide Crystals Triple Phosphate Crystals Tyrosine Crystals Uric Acid Crystals Renal Epithelial Cells Squamous Epithelial Cells Transitional Epithelial Cells

CP-15 CP-16 CP-16 CP-16 CP-16 CP-17 CP-17 CP-17 CP-17 CP-18 CP-18 CP-18 CP-19 CP-19 CP-19 CP-19 CP-20 CP-20 CP-20 CP-20 CP-20 CP-20 CP-21 CP-21 CP-21 CP-21 CP-21 CP-21

Figure Figure Figure Figure

4.87 4.88 4.89 4.90

Epithelial Cells and Lipid Droplets Capillaria plica Starch Granules Yeast

CP-22 CP-22 CP-22 CP-22

Pain Scales Figure 9.1 CSU Canine Acute Pain Scale Figure 9.2 CSU Feline Acute Pain Scale

CP-23 CP-24

FIGURE LIST

xix

Preface This second edition of Veterinary Technician’s Daily Reference Guide: Canine and Feline continues from the success of the first edition. As our profession continues to grow and demand more of veterinary technicians, this reference guide has done the same. With the obvious inclusion of updated medical information, this second edition contains an expansive amount of more in-depth skill descriptions allowing the technician to reach an even higher level of care. Its purpose is not to present ideas for the first time but rather to refresh or expand the veterinary technician’s current knowledge. This manual provides the link between the formal learning environment and the daily clinical setting. The goals are to increase confidence and technical skill and to allow veterinary technicians to provide clear client education. This book covers all areas of the veterinary technology profession pertinent to canines and felines, from the basics of physical examinations to advanced skills of chemotherapy administration. We are confident that the veterinary technician will find a daily need for this invaluable resource. In the end, it is our goal that this book will facilitate improved care for patients and the owners who rely on experienced veterinary technicians.

SUMMARY OF KEY FEATURES Comprehensive Guide. This book was written as a quick reference guide. Its purpose is to assist an already trained and licensed veterinary technician throughout the work day—providing a refresher for a seldom-taken radio-

graph, for example, or a pharmacology reminder to help answer a client’s question. The veterinary technology student will also find this book useful as a supplement to more in-depth textbooks as they finish training and join the workforce. Unique Chart and Table Format. The format of this book uses charts and tables for the efficient retrieval of pertinent information. As a result, very little prose text has been included. This unique format leads technicians straight to the answers they need to perform a task quickly. Extensive Art Program. The art program, which includes more than 200 illustrations and photographs, will provide visual assistance to the technician performing laboratory tests, dentistry, client education, and much more. The color insert makes the artwork very clear and easy to use. Expansive Indexing. A comprehensive table of contents and references at the beginning and throughout each chapter will ease the movement through this information-rich text. It is our expectation that this book will be of great assistance to the veterinary technician. Use of this book should result in enhanced performance of a veterinary technician’s duties and, therefore, improved care for patients. Candyce Jack, LVT Patricia Watson, LVT

xxi

Acknowledgments We would like to express our heartfelt thanks to all the people who gave support and guidance during the forming of this book. We also appreciate the professional courtesy extended by Phoenix Laboratory, DentaLabels, Wiley-Blackwell, American Society of Anesthesiologists, Dr. Peter Hellyer, Dr. Narda Robinson, Tara Raske, International Veterinary Association of

Pain Management, Greg deBoer, Anne Rains, Dr. David Stansfield, Novartis, Dr. James H. Meinkoth, Oklahoma State University, Gary Averbeck, Dr. Robert K. Ridley, Kansas State University, and Dr. Jay R Georgi, Dr. Daniel Chan, and Mikki Cook, LVT, Hill’s Pet Nutrition, Animal Emergency and Trauma Center.

Contributors Dina Andrews, DVM, PhD, Dip. ACVP Lisa Coyne, LVT Cindy Elston, DVM J. Michael Harter, DVM Joyce Knoll, VMD, PhD, Dip. ACVP Brita Kraabel, DVM Bob Kramer, DVM, Dip. ACVR Veronica Martin, LVT Linda Merrill, LVT, VTS (Small Animal Internal Medicine)

Kathryn Michel, DVM, MS, Dip. ACVN Jeb Mortimer, DVM Richard Panzer, DVM, MS Patrick Richardson, DVM Nancy Shaffran, CVT, VTS (ECC) Stuart Spencer, DVM Cheryl Stockman, MT (ASCP) Laura Tautz-Hair, LVT, VTS (ECC) Sandy Willis, DVM, MVSc, Dip. ACVIM

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Veterinary Technician’s Daily Reference Guide: Canine and Feline Second Edition

Section

One

Anatomy

Chapter

1

1

Anatomy Anatomy 6 Figure 1.1. Overall 6 Figure 1.2. Regional Lymph Nodes 6 Musculature 6 Figure 1.3. Musculature: Lateral View 6 Skeletal 7 Figure 1.4. Skeletal: Lateral View 7 Figure 1.5. Skeletal: Dorsal View 7 Internal Organs 8 Figure 1.6. Internal Organs: Left Lateral View 8 Figure 1.7. Internal Organs: Right Lateral View 8 Figure 1.8. Internal Organs: Ventral View 8 Circulatory System 9 Figure 1.9. Circulatory: Dorsal View of Heart 9 Figure 1.10. Circulatory: Internal View of Heart 9

Figure 1.11. Circulatory: Heart Valves 10 Figure 1.12. Circulatory: Lateral View 10 Nervous System 10 Figure 1.13. Nervous System: Lateral View of Brain Figure 1.14. Nervous System: Lateral View 11 Urogenital 11 Figure 1.15. Urogenital: Ventral View, Female 11 Figure 1.16. Urogenital: Ventral View, Male 12 Figure 1.17. Urogenital: Lateral View, Male 12 Eye 13 Figure 1.18. Eye 13 Ear 13 Figure 1.19. Ear 13

10

5

1

ANATOMY For a veterinary technician to be able to accurately complete many of his or her daily tasks, a clear understanding of the anatomy of the canine and feline body is needed. The following diagrams show the basic layout of the body systems, highlighting the areas of interest that are most commonly accessed in daily medicine practices ranging from the correctly positioned radiograph to a single-stick venipuncture.

Overall See Skill Box 2.6 Regional Lymph Node Examination, page 34.

Figure 1.2 Regional lymph nodes.

Musculature Sternocephalicus Cleidocervicalis External Trapezius abdominal Latissimus oblique dorsi

Middle gluteal Superficial gluteal Biceps femoris

Deltoids

Cleidobrachialis

Figure 1.1 Overall.

Pectoralis major Triceps

Sartorius Deep Gracilis pectoral Pectoralis minor Semitendinosus

Figure 1.3 Musculature: lateral view.

6

SECTION ONE: ANATOMY

Gastrocnemius

Skeletal

1

See Skill Box 2.8 Orthopedic Examination, page 36. Orbit

Zygomatic arch

Zygomatic arch Atlas Axis Cervical Spinous Iliac Thoracic process Lumbar crest Ilium Ischial tuberosity Greater trochanter

Maxilla

Mandible Spine of scapula Scapula

Wing of atlas

Axis

T1

Sacrum Ischium Costal arch

Ribs Humerus Ulna

Spine of scapula

Scapula

Xyphoid Patella Sternum Fibula Ulna

Radius Carpus Metacarpus

Femur

Atlas

Tibia Tarsus Metatarsus

L1 Phalanges

Figure 1.4 Skeletal: lateral view.

Iliac crest Ilium Greater trochanter of femur

Sacrum

Ischial tuberosity

Figure 1.5 Skeletal: dorsal view.

CHAPTER 1 / ANATOMY

7

1

Internal Organs

Esophagus

See Skill Box 2.4 Abdominal Examination, page 33. See Color Plates 1.6–1.8. CP-1.

Trachea

Lung

Heart Uterine horn Ovary

Ureter Colon

Right kidney

Lungs

Anus

Diaphragm

Liver

Liver

Gall bladder Common bile duct Liver Duodenum Pancreas Transverse colon Ascending colon Cecum

Liver Heart Greater omentum (covering small intestines)

Urinary bladder

Figure 1.6 Internal organs: left lateral view.

Rectum Esophagus Trachea

Lungs

Spleen

Stomach

Liver

Thymus

Ureter

Small intestines Urinary bladder

Figure 1.7 Internal organs: right lateral view.

SECTION ONE: ANATOMY

Spleen Jejunum Ileum

Descending colon

Mesentery

Anal gland

Left kidney

Heart (cardiac notch)

8

Lesser omentum Stomach Greater omentum (cut)

Colon

Figure 1.8 Internal organs: ventral view.

Circulatory System

Left subclavian artery

See Skill Box 2.2 Cardiac Examination, page 30. See Color Plates 1.9, 1.10, and 1.12. CP-1, 2.

1

Aorta Superior vena cava

Left subclavian artery

Superior vena cava

Right auricle

Right atrium

Aortic arch Pulmonary arteries Left atrium

Pulmonary veins

Left auricle

Right atrium

Tricuspid valve Right ventricle

Pulmonary veins Left ventricle

Apex

Inferior vena cava

Coronary artery Right ventricle Apex

Semilunar valves of aorta

Left atrium

Figure 1.9 Circulatory: dorsal view of heart.

Bicuspid valve Left ventricle

Chordae tendineae Ventral papillary muscle

Figure 1.10 Circulatory: internal view of heart.

CHAPTER 1 / ANATOMY

9

1

Figure 1.12 Circulatory: lateral view.

Nervous System See Color Plate 1.14. CP-2.

Epithalamus

Corpus collosum

Figure 1.11 Circulatory: heart valves. Cerebellum

Olfactory bulb Optic chiasm

Spinal cord

Thalamus Medulla oblongata

Hypothalamus

Pituitary

Figure 1.13 Nervous system: lateral view of brain.

10

Urogenital

Vagosympathetic trunk Brachial plexus

Lumbo-sacral plexus

1

See Skill Box 2.4 Abdominal Examination, page 33. See Skill Box 12.10 Urinary Catheterization, page 435.

Vagus Sciatic

Diaphragm

Femoral Radial

Esophagus

Adrenal gland

Tibial

Median Kidney Ulnar

Uterine tube

Figure 1.14 Nervous system: lateral view.

Ovarian ligament

Ovary Colon

Ureter Round ligament

Broad ligament

Uterus: Horn Body

Urinary bladder

Urethra Rectum Vagina

Anal gland

Figure 1.15 Urogenital: ventral view, female.

CHAPTER 1 / ANATOMY

11

Kidneys

1

Colon Diaphragm

Esophagus

Prostate gland

Adrenal gland

Kidney

Urethra Ureter Urinary bladder Spermatic cord Prepuce Ureter

Colon

Ductus deferens Epididymis

Urinary bladder

Testis Prostate gland

Spermatic cord Urethra Rectum

Bulbourethral gland Ductus deferens

Penis Prepuce Glans penis

Epididymis Anal gland

Testis

Figure 1.16 Urogenital: ventral view, male.

12

SECTION ONE: ANATOMY

Os penis

Glans penis

Figure 1.17 Urogenital: lateral view, male.

Eye

Ear Bulbar conjunctiva

Sclera

1

See Skill Box 2.5 Otoscopic Examination, page 33. See Skill Box 2.13 Ear Cleaning and Flushing, page 55.

Posterior chamber Choroid Retina

Pinna Iris Cornea

Vitreous humor Lens Optic disc

Anterior chamber

Third eyelid

Suspensory ligament

Optic nerve

Palpebral conjunctiva Vertical auditory canal

Figure 1.18 Eye.

Semicircular canals Vestibule Cochlea

Oval window

Horizontal auditory canal

Auditory nerve

Round window Tympanic membrane Middle ear cavity Eustachian tube (auditory)

Figure 1.19 Ear.

CHAPTER 1 / ANATOMY

13

Section

Two

Preventative Care Chapter 2: Preventative Care and Vaccinations Chapter 3: Nutrition 57

17

Chapter

2

2

Preventative Care and Vaccinations Physical Examinations 18 Preliminary Examination 19 Physical Examination 20 Pediatric Physical Examination 23 Normal Parturition 26 Care and Feeding of Orphaned Puppies and Kittens 27 Geriatric Physical Examination 28 Cardiac Examination 30 Pulmonary Examination 32 Abdominal Examination 33 Otoscopic Examination 33 Regional Lymph Node Examination 34 Neurologic Examination 34 Orthopedic Examination 36 Vaccinations 37 Guidelines to Follow When Vaccinating an Animal 37 Canine Transmissible Diseases 38 Coronavirus, Distemper 38

Hepatitis, Infectious Tracheobronchitis 39 Leptospirosis, Lyme Disease 41 Parvovirus, Rabies 42 Canine Vaccination Protocol 44 Feline Transmissible Diseases 44 Feline Calicivirus 44 Feline Infectious Peritonitis 46 Feline Panleukopenia Virus, Feline Immunodeficiency Virus 47 Feline Leukemia Virus, Feline Rhinotracheitis Virus 49 Feline Vaccination Protocol 51 Animal Care 51 Client Education: Home Dental Care 52 Grooming 53 Bathing 53 Nail Trimming 54 Anal Sac Expression 54 Ear Cleaning and Flushing 55

17

Key Words and Phrasesa Alopecia Amyloid Axillary Canarypox vector Core Cryptorchidism Desquamative Diathesis ELISA Encephalopathy Epistaxis Fistula Fontanelle Granulomatous Halitosis Hemoagglutination Hyaluronic acid Hyperpathia Intussusception Lymphadenopathy

2

a

Lyophilized Melena Noncore Nystagmus Panniculus Papilloma PCR Petechia Prodromal Proprioception Proteoglycan Rales Rhonchi Stenosis Strabismus T-lymphocytes Tortuous, redundant aorta Vascularity Western blot Whelping

Abbreviations

Additional Resources, page

APTT, activated thromboplastin time BCS, body condition score BUN, blood urea nitrogen CBC, complete blood count CNS, central nervous system CPV, canine parvovirus CSF, cerebrospinal fluid DIC, disseminated intravascular coagulation ELISA, enzyme-linked immunosorbent assay F, Fahrenheit FCV, feline calicivirus FECV, feline enteric coronavirus FeLV, feline leukemia FHV-1, feline viral rhinotracheitis FIP, feline infectious peritonitis FIV, feline immunodeficiency virus FPV, feline panleukopenia GIT, gastrointestinal tract IFA, immunofluorescent assay IgG, immunoglobulin gamma G IgM, immunoglobulin gamma M IN, intranasal O2, oxygen OVH, ovariohysterectomy PCR, polymerase chain reaction PT, prothrombin time RBC, red blood cell RV, rabies vaccine SQ, subcutaneously v, variable

Abdominocentesis, 429 Anesthesia, 439 Blood transfusions, 367 CBC, 105 Cesarean section, 542 Chemistry panel, 74 Coagulation tests, 115 Coupage, 432 Dentistry, 497 Ear cytology, 88 Figure: Ear, 13 Figure: Heart, 9 Figure: Internal organs, 8 Figure: Heart valves, 10 Figure: Lymph nodes, 6 Fluid therapy, 359 General medicine, 201 Heat administration, 346 Injections, 348 Laboratory, 71 Microbiology, 122 Nebulization, 432 Nutritional support, 414 Oxygen therapy, 375 Pharmacology, 567 Physical examination, 18 Physical therapy, 558 Radiology, 159 Surgery, 521 Thoracocentesis, 431 Urinalysis, 147

Key words and terms are defined in the glossary on page 631.

PHYSICAL EXAMINATIONS A well-done physical examination gives the clinician invaluable information in the assessment of an animal’s health. Technicians can assist the veterinarian by understanding the pertinence of each part of the examination and by

18

SECTION TWO: PREVENTATIVE CARE

being able to conduct an examination in an orderly, precise, and timely fashion. Physical examinations are conducted prior to immunizing, before an anesthetic procedure, and in conjunction with any visit to the veterinarian for a specific problem. The following charts will cover methods and specific areas of the physical examination in both pediatric and adult patients.

Vital Signs

History

Table 2.1 / Preliminary Examination Definition/Normal/Abnormal

Equipment and Technique

Chief Complaint

• The current issue for which the owner is bringing the animal to the clinic

• Current history • Current appetite, water intake, urination and defecation behavior, recent temperament, and current medications are noted. Recent activities to which the animal may have been exposed or changes in the home environment are also noted.

Past History

• Previous medical conditions that may exacerbate the current complaint

• Past history • Immunization dates as well as current medical therapies are noted.

Signalment

• Age, breed, sex, and reproductive status

• N/A

General Appearance

• The patient’s overall health

• Visual evaluation of the condition of animal’s coat, skin, and temperament

Heart Rate • Cardiac function

Normal • Canine: 70–180 beats/min • Feline: 110–220 beats/min Abnormal • Canine: <70 and >160 beats/min • Feline: <100 and >200 beats/min

• Direct palpation of chest wall or pulse • Auscultation of the thoracic cavity • See Skill Box 2.2, Cardiac Examination, page 30. • Electrocardiograph • See Chapter 8, Patient Care, page 338. • Doppler pulse monitor

Respiration • Reflects proper oxygenation of the body’s tissues • Ability to eliminate carbon dioxide from the blood

Normal • Canine: 10–30 breaths/min • Feline: 25–40 breaths/min Abnormal • <8 breaths/min

• Auscultation of the thoracic cavity • See Skill Box 2.3, Pulmonary Examination, page 32. • Pulse oximetry • Calculates the O2 saturation of hemoglobin in circulating RBCs • The probe is placed on an easily accessed capillary bed (e.g., tongue, lip fold, nasal septum, pinna, prepuce, vulva, skinfolds, or toe web) • Normal: 99–100% • Abnormal: <97%, 90% is hypoxemia and must be corrected

Pulses • Cardiac function

Normal • Match rate and rhythm of heart rate Abnormal • Weak, bounding, thready, irregular, deficits

• Direct palpation • Direct digital pressure over the left and right femoral artery • Evaluate pulse quality, strength, rate and symmetry.

Mucous Membranes • Blood loss, anemia, and poor perfusion

Normal • Pink Abnormal • Pale: blood loss, anemia or poor perfusion • Cyanotic: shortage of oxygen

• Visual observation • Observed at the gingival, tongue, buccal mucous membranes, conjunctiva of the lower eyelid, mucous membrane lining the prepuce or vulva

Capillary Refill Time • Reflects the perfusion of tissues with blood

Normal • 1–2 seconds Abnormal • >2 seconds

• Direct palpation • Direct digital pressure is applied to the mucous membranes until blanched and then timed for blood (pink color) to return.

Temperature • Circulation

Normal • 100.5–102.5° F Abnormal • <100° and >103° F

• Direct palpation of paws and ears • Rectal thermometer • Temperature probe (e.g., rectal or esophageal)

Weight

Normal/Abnormal • See Table 3.2, Body Condition Scoring System, page 61.

• Recorded in kilograms and pounds • Note BCS and dietary history

CHAPTER 2 / PREVENTATIVE CARE AND VACCINATIONS

2

19

Table 2.2 / Physical Examination Area

Head and Neck

2

20

Specific Region

Examination Findings

History

Head (general)

• Symmetry, alopecia, tumors or swellings, rashes, head tilt, and uniformed muscle mass on skull

• Head tilt or shaking? • Seizures?

Eyes (lids, eyeball, conjunctiva, sclera, pupil, cornea, lens) • Visual examination • Ophthalmic examination

• Normal: bright, clear, uniform, responsive • Cysts, conformity, lash growth, third eyelid position and size, symmetry, ocular discharge, nystagmus, positioning within orbit: protruding vs. sunken, color, vascularity, uniformity of pupils, scars, ulcerations, pigmentation, and opacities

• Pain? • Blinking, squinting, rubbing or pawing? • Discharge? (e.g., quantity, consistency, color, uni- or bilateral) • Blindness?

Muzzle • Visual examination

• Symmet, inflammation, swelling, abscessed teeth and pain on opening mouth

• Rubbing or pawing?

Nares • Visual examination

• Symmetry, movement on inspiration (should move laterally) and discharge

• Sneezing or heavy breathing? • Discharge? (e.g., quantity, consistency, color, uni- or bilateral)

Oral Cavity (lips, mucous membranes, teeth, hard and soft palate, tongue, pharynx, tonsils) • Visual examination

• Normal: symmetrical, pink, slightly moist • Halitosis, inflammation, tumors or papillomas, anatomic defects, excessive salivation, crusting, pigment changes, color and capillary refill time, tacky, periodontal status, ulcerations, and foreign bodies • See Chapter 14, Dentistry, page 497.

• Excessive salivation or dripping water after drinking? • Inappetence or difficulty eating? • Changes? (e.g., gingival pigmentation, bark, meow)

Ears • Visual examination • Otoscopic examination

• Normal: clear and dry • Debris, exudate, odor, inflammation, response to sound, and sensitivity to canal massage or palpation • See Skill Box 2.5 Otoscopic Examination, page 33.

• Shaking head or scratching ears? • Discharge? (e.g., quantity, consistency, color, uni- or bilateral) • Hearing loss?

Lymph Nodes (submandibular) • Palpation

• Normal: firm, oval, and freely movable • Symmetry and size • See Skill Box 2.6 Regional Lymph Node Examination, page 34.

• Increase in size?

Salivary Glands (mandibular, parotid) • Palpation

• Normal: irregular, bumpy texture • Symmetry and size (do not confuse with submandibular nodes)

Neck (throat, trachea, larynx, thyroid, thoracic inlet) • Palpation • Auscultation

• Coughing or sounds during examination, deviation or displacement, tumors, swelling, stridor, or jugular pulse waves

SECTION TWO: PREVENTATIVE CARE

• Gagging, retching, difficulty swallowing? • If a cough is noticed, does the cough occur throughout the day? • Travel or exposure to other dogs?

Table 2.2 / Physical Examination (Continued)

Thoracic Cavity

Trunk and Limbs

Area

Specific Region

Examination Findings

History

Trunk (general) • Visual examination • Palpation

• Normal: visible sheen and coat completeness • Body form and weight, symmetry, tumors, alopecia, inflammation, ectoparasites or their residues, crusts, scales, pustules, and hydration status

• Changes? (e.g., pigmentation, odor, hair loss, texture) • Allergen exposure? (e.g., type of bedding, feathers, carpets, indoor plants, tobacco smoke) • Pruritus? (e.g., behavior, frequency) • Scratching, biting, licking? • Did pruritus precede or coincide with lesions? • Bathing or grooming habits? • Changes in diet?

Lymph Nodes (prescapular, axillary, inguinal, popliteal) • Palpation

• Normal: firm, oval, and freely movable (axillary or disc shaped) • Size and consistency • See Skill Box 2.6 Regional Lymph Node Examination, page 34.

• Increase in size? • Limping and/or favoring limb(s)?

Limbs (muscle, bone, joints, paws) • Visual examination • Palpation

• Symmetry, inflammation, tenderness, tumors, range of motion, gait, atrophy, flexion and extension, interdigital, nails/nail bed, and knuckling

• Licking paws?

Lungs • Auscultation • Percussion

• Rate, depth, and pattern of breathing (rales or rhonchi) and lung sounds (absence of lung sounds may indicate pleural effusion, and dull sound may indicate fluid filled or solid lungs) • See Skill Box 2.3 Pulmonary Examination, page 32.

• Fainting? • If cough is present, does it change throughout the day or worsen with exertion? • Recent travel?

Heart • Auscultation

• Dysrhythmias, murmurs, verify femoral and metatarsal pulses coincide with the heart rate (e.g., no pulse deficits) • See Skill Box 2.2 Cardiac Examination, page 30.

• Fainting, collapsing, or exercise intolerance? • Panting? • Coughing? (e.g., description, frequency)

CHAPTER 2 / PREVENTATIVE CARE AND VACCINATIONS

21

2

Table 2.2 / Physical Examination (Continued) Area

Perineal

Abdomen

2

22

Specific Region

Examination Findings

History

Kidneys • Palpation

• Normal: oval shaped with indented side, firm, and smooth • Size, shape, contours of surface, symmetry (between left and right kidneys) and pain

• Excessive water consumption or urinating?

Liver • Palpation, lateral recumbency

• Normal: edges are smooth and well defined • Asymmetric or irregular surface? • Extension beyond costal arch may indicate hepatomegaly

Urinary Bladder • Palpation

• Normal: palpable when urine filled, thin wall with flexibility • Size, tone and turgidity

• Urination (e.g., frequency, quantity, behavior, odor) • Foul odor, color change, or blood? • Straining? • Inappropriate urination?

Small Intestines • Palpation

• Normal: not palpable or mildly gas filled • Tumors, foreign bodies, and pain, thickened/firmness on palpation

• Vomiting, diarrhea, or constipation? (e.g., description, quantity, frequency, behavior) • Time since last bowel movement?

Mammary Glands • Visual examination • Palpation

• Normal: fleshy, semifirm, or fatty character • Estrus/diestrus: firmer and enlarged • Tumors, cysts, inflammation, temperature, discharge (suppurative), pain, and firmness

• If intact female, when last whelping occurred? • When was OVH performed?

General • Visual examination

• Tumors, fistulas, exudate and hernias

• Reproductive status?

Vulva • Visual examination

• Normal: lochia • Size, inflammation, and discharge from or between perivulvar folds

• Last heat cycle, mating, or whelping? • Discharge (e.g., quantity, consistency, color, odor)

Penis • Visual examination • Palpation

• Normal: preputial discharge • Tumors, inflammation, and discharge

• Normal urination? • Blood or urine color change? • Discharge (e.g., quantity, consistency, color, odor)

Scrotum • Visual examination • Palpation

• Descended testicles, swelling, and symmetry

• Pain when sitting?

SECTION TWO: PREVENTATIVE CARE

Table 2.3 / Pediatric Physical Examination

This chart is designed to show the specific areas to note on puppies and kittens. A full examination should be conducted following Table 3.3, General Physical Examination. Age

Puppy Normal

Temperament • Visual examination

Birth–6 weeks

• First 2–3 weeks should consist of eating and sleeping. • Nursing should be vigorous and active with a good “suckle reflex.” • Active playtime with mother and littermates from 3 weeks on

Body Weight

Birth–4 weeks

• • • • •

5 weeks–6 months

• Gain 1–2 g/day/lb of adult body weight • Obtained 50% of adult weight

• Gain 10–15 g/day on average

Reached adult weight

• Small breed: 8–12 months • Medium breed: 12– 18 months • Large–giant breed: 18–24 months • By maturity, most canines will ↑ birth weight 40–50×

• 10 months

Coat/Skin • Visual examination • Flea comb

Birth–6 months

• Shiny and complete hair coat

• State of hydration • Completeness of hair cover, condition of foot pads, wounds, bacterial infections, external parasites, or dermatophytosis

Temperature • Rectal thermometer

Birth–1 week

• 96–98° F • Cannot regulate own body temperature for first 3 weeks (puppy) or 1 week (kitten) • Neonates should never be left unattended or warmed on electric heating pads, because their neuromuscular reflexes are not present until 7 days of age.

• Hyper- or hypothermia • Burns

2–4 weeks

• 99–100.5° F

General Appearance

Specific Region/Examination Method

Toy: 100–400 g Medium: 200–300 g Large: 400–500 g Giant: >700 g Birth weight should double in days 10–12

Kitten Normal

• 100 g • Birth weight should double in 14 days.

Evaluation • Constant crying, extreme inactivity, and/or failure to gain weight can be signs of inadequate milk consumption. • Separation from mother and littermates before 6 weeks of age can lead to numerous behavioral problems later in life. • Failure to gain weight is often the first sign of illness. • Body weight should be checked initially, 12 hours after birth, and daily for 2 weeks; then checked weekly.

CHAPTER 2 / PREVENTATIVE CARE AND VACCINATIONS

23

2

Table 2.3 / Pediatric Physical Examination (Continued)

Head

2

24

Specific Region/Examination Method

Age

Puppy Normal

Eyes • Visual examination • Penlight • Ophthalmic examination

Birth–6 months

• Eyes open around 5–14 days • Iris is blue gray. • Changes to adult color at approximately 4–6 weeks of age • Adult vision at 5–10 weeks of age • Pupillary light responses may not be evident until 21 days of age. • Strabismus or deviation of eyes at 3–5 months of age

• Discharge, squinting or holding eye(s) closed, rubbing or pawing at eye(s)

Ears • Visual examination • Otoscopic examination

Birth–6 months

• Complete hearing at 4–6 weeks of age • External ear canals open at 6–14 days and are completely open by 17 days. • Canals may be full of desquamative cells and some oil droplets.

• Size and position • Exudate and odor for possible bacterial or yeast infection or mites

Mouth • Penlight • Tongue depressor or cotton swab

Birth–3 months

• Sucking reflex is present at birth and disappears at 3 weeks of age. Deciduous tooth eruption • Incisors: 2–4 weeks • Canines: 3–5 weeks • Premolars: 4–12 weeks

• Hairlip, cleft palate, sucking reflex, occlusion or malfunction of jaw bones (malocclusion)

4–6 months

Permanent tooth eruption • Incisors: 3–5 months • Canines: 4–7 months • Premolars: 4–6 months • Molars: 4–5 months

• Occlusion or malfunction of jaw bones (malocclusion)

Nose • Visual examination

Birth–6 months

• Normal adult appearance

• Obstruction, stenosis, discharge, or abnormal shape, swelling

Skull • Visual examination

Birth–4 weeks

• Normal adult appearance

• Open fontanelle (soft spot on the forehead)

SECTION TWO: PREVENTATIVE CARE

Kitten Normal

Evaluation

Table 2.3 / Pediatric Physical Examination (Continued) Age

Puppy Normal

General Appearance • Visual examination

Birth–6 months

• Symmetrical chest wall

• Wounds and rib fractures • Congenital sternal or spinal abnormalities

Limbs Perineum Genitals

Kitten Normal

Evaluation

Heart • Visual examination • Stethoscope with 2 cm bell and 3 cm diaphragm

Birth–4 weeks

• Heart rate: 220 beats/min • Heart rhythm is a regular sinus rhythm

• Heart rate and pattern • Murmurs (should be noted and veterinarian consulted, as some can be normal/physiologic)

5 weeks–6 months

• Heart rate: 70–180 beats/min

• Heart rate: 110–200 beats/min

Lungs

Birth–4 weeks

• Respiratory rate: 15–35 breaths/min

• Respiratory rate: 25– 35 breaths/min

5 weeks–6 months

• Respiratory rate:10–30 breaths/min

• Respiratory rate: 25– 40 breaths/min

General Appearance • Visual examination

Birth–4 weeks

• Umbilical cord falls off in 2–3 days.

• Umbilical hernia, inflammation, or infection/ulceration

Internal Organs • Palpation

Birth–4 weeks

• Kidneys are palpable in kittens and some puppies. • Normal spleen will sometimes be palpable in an older puppy if foreleg is extended, allowing organs to fall caudally; spleen only palpable if enlarged in kittens. • Liver margins should not extend past the ribs. • Stomach will feel like a large fluid-filled sac if full. • Intestines are soft and freely movable without pain and may be fluid or gas filled. Thickened/ ”ropy” feel may indicate endoparasitism. • Urinary bladder should have resistance to urine outflow.

• Enlarged or abnormally small organs, pain on palpation, masses • Intussusception—a sausage-like mass and very painful

Forelimbs/Hindlimbs • Visual examination • Palpation

Birth–6 months

• Normal adult appearance (breed-influenced)

• Wounds, bruises, or swelling • Deformities or ↑ or ↓ range of motion in joints

Genitalia • Visual • Palpation

Birth–6 months

• Normal adult appearance • Descended testicles by 4–6 weeks of age (diagnose cryptorchid after 16 weeks)

• Cryptorchidism, vaginitis, congenital abnormalities

Anus • Visual • Palpation

Birth–6 months

• Normal adult appearance

• Rectal prolapse, inflammation, or irritation • Defecation/urination on their own usually occurs at 2–3 weeks.

2

Abdomen

Thorax

Specific Region/Examination Method

• Breathing rate and pattern • Asymmetrical or absent lung sounds

CHAPTER 2 / PREVENTATIVE CARE AND VACCINATIONS

25

Table 2.4 / Normal Parturition

2

In late term pregnancy (58–63 days), the bitch or queen should be observed for signs of labor. These may include a rectal temperature drop to <100° F, vulvar discharge, and leaking milk. Once labor starts, the female should be left alone but observed occasionally progression and/or signs of complications. Stage

Time

Observations

Complications

I Prelabor

• 6–12 hours, up to 24

• Restless, nesting behavior, getting up and down, nervous, panting, vomiting • Nesting behavior (e.g., arranging bedding, chewing up paper)

• Black, green, or red vaginal discharge

II Active Labor, Whelping III Expulsion of Placenta

• 3–6 hours, up to 24

• Contractions lying on side or standing in a urination stance • Placenta at the vulva, a neonate should be seen within 15 minutes • Mother will chew the placenta to free the neonate, sever the umbilical cord, and lick the neonate for stimulation. • Placenta should be seen within 5–15 minutes. • The next neonate should follow in 1–2 hours.

• 30–60 minutes of strong contractions with no neonate produced • >2 hours between pups (>1 hour between kittens) is an emergency • Mother may not release the neonate and sever the umbilical cord. • Eating multiple placentas may lead to indigestion and diarrhea. • Queen: if stressed may stop and restart labor the next day

Postpartum

• 1–2 months

• Bitch: 8–10 weeks of bloody discharge • Queen: 3 weeks of black or red discharge

• Mastitis (e.g., fever, lethargy, swollen glands), metritis (e.g., foul smelling discharge), retained placenta (e.g., green discharge) • Eclampsia (e.g., tremors, excitation)

26

• 20–60 minutes per neonate

SECTION TWO: PREVENTATIVE CARE

Skill Box 2.1 / Care and Feeding of Orphaned Puppies and Kittens Housing • Use a box with tall sides to avoid escape, such as a cardboard pet carrier. • Line the bottom of the box with towels and place a diaper or pee pad on top for easy cleaning. • The box will need to be cleaned frequently to keep the neonates clean and dry. Temperature • Neonates are unable to maintain their own body heat; they rely on the ambient temperature and littermates. • The environment should be draft free with a ambient temperature gradient measured by a thermometer. • Electric heating pads and heat lamps should not be used due to the risk of overheating and burns. • The ambient temperature should be 85–90° F for the first week, 80° F for weeks 2–4, and 70° F for week 5.

• Warm the formula to a comfortable temperature, place the neonate in a comfortable dorsal position, and hold the bottle up in a position to closely mimic that of the mother. Ensure that the nipple does not contain air and the bottle is tipped up to avoid air ingestion. Neonates have a vigorous suckling response and can overfeed if not monitored. Milk bubbling out of the neonate’s nose may indicate overzealous feeding or a hole in the nipple that is too large. A satisfied neonate is quiet with a slightly enlarged abdomen. Following each feeding, burping may be necessary to expel excess air ingested. • A nipple bottle is most commonly used, but a feeding tube can be ideal in skilled hands for weak or premature neonates See Skill Box 11.3 Nasoesophageal/Nasogastric Tube, page 415. • With all methods of feeding, care should be taken to avoid aspiration pneumonia, a complication seen with forced nursing, squeezing the bottle, improper feeding tube use, and volume overload. Health • Hydration should be monitored in the neonate by mucus membranes, eyes, urine specific gravity, and urine color.

Diet

• A neonate should gain 10% of its birth weight daily.

• Commercial replacement diets (e.g., Esbilac, KMR) are the best choice for diet replacement.

• Crying for >15 minutes is a sign of distress (e.g., hunger, cold, neglected, pain).

• When commercial diets are not available, the following recipe can be used in the interim.

Urination and Defecation

• 1/2 cup whole milk, 1/2 cup water, 1 tsp. salad oil, 1 drop multivitamins, 2 egg yolks, 2 Tums (antacid) crushed

• For the first 3 weeks, the neonate must be stimulated to urinate and defecate after each feeding.

• Blend all ingredients in a blender, keep refrigerated, and use within 48 hours.

• With the neonate held securely in 1 hand (possibly with a towel) over a sink, gently massaging the lower abdomen in a circular motion. The genitals may also be rubbed with a warm, moist cotton ball.

• The above diet provides 1.2 kcal/mL, which is the same as commercial diets. • Neonates are fed 22–26 kcal/100 g body weight for the first 12 weeks of life. The diet should be gradually increased over 2–3 days to the recommended daily amount to avoid overfeeding and diarrhea.

• The genitals should be cleaned and dried to avoid skin irritation. • Urine and feces should be seen at almost every feeding and in the box. • Feces should be soft, but not green or yellow watery. Overfeeding is the most common cause of diarrhea; further dilute the formula by 1/3 for 2 days.

Feeding • The neonate will cry when hungry, but feeding should initially be expected every 2–3 hours.

CHAPTER 2 / PREVENTATIVE CARE AND VACCINATIONS

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2

Table 2.5 / Geriatric Physical Examination

This chart is designed to show the specific areas to note on geriatric animals. A full examination should be conducted, following Skill Box 2.2, General Physical Examination. However, geriatric animals go through additional changes as a result of the natural aging process and a physical is recommended every 6 months. Many of these changes cannot be visualized on a physical examination, but they may be inferred through the general examination and from discussion with the owner. These symptoms may contribute to or initiate more serious medical conditions, thereby making their determination valuable to the clinician.

General Appearance

Specific Region

Head

2

28

Effects

Associated With

Skin

• ↓ Elastin and collagen • ↓ Blood flow to skin • Thinning of skin and coat

• Ineffective barrier to pathogens • May require more maintenance by owner

Toenails

• ↑ Length because of ↓ activity • More fragile, crumble when trimmed

• Difficulty walking • Wounds in foot pads

Musculature

• ↓ Strength • ↓ Tone

• Muscle atrophy and coordination

Eyes

• • • •

• Atrophy of the iris and ciliary muscles • Nuclear sclerosis

Ears

• Hearing loss

• Loss of cochlear hair cells

Nose

• ↓ Sense of smell

• ↓ Function of olfactory nerve endings, which can affect their eating habits

Neck

• Thyroid nodules

• Hyperthyroidism (feline), tumor

SECTION TWO: PREVENTATIVE CARE

Vision loss ↓ Pupillary light response Change in lens opacity Optic lens hardening

Associated With

Brain

• Amyloid deposition • Memory loss • Personality changes

• Cognitive dysfunction disorder • ↓ Glucose tolerance • Cognitive dysfunction disorder

Lungs

• • • • •

• Rarely a cause of concern unless patient needs to undergo an anesthetic procedure

Heart

• ↑ Sternal contact • Tortuous, redundant aorta (feline) • Radiographic changes

Kidney

• • • • •

Liver

• ↓ Protein synthesis • ↓ Metabolic function

• Liver disease

Limbs

Specific Region

Joints/Cartilage

• ↓ Production of chondroitin sulfate, keratin sulfate, and hyaluronic acid • ↓ Proteoglycan content

• Degenerative joint disease

Urethral Sphincter

• ↓ Tone

• Primary urethral sphincter incontinence

Immune System

• ↓ Function

• Chronic disease • ↑ Susceptibility to infections

Blood

• ↓ Ability to respond to RBC demand • Hypertension

• Anemia • Renal or endocrine disease

Internal Organs

Effects

Genitals

Table 2.5 / Geriatric Physical Examination (Continued)

Loss of lung elasticity ↓ Tidal volume ↓ Expiratory reserve Diminished cough reflex ↑ Density on lung radiographs

↓ ↓ ↓ ↓ ↑

Size Glomerular filtration rate Renal blood flow Ability to handle potassium Mineralization of renal pelvis

2

• Rarely a cause of concern

• Kidney disease • PU/PD • No concern known

CHAPTER 2 / PREVENTATIVE CARE AND VACCINATIONS

29

Skill Box 2.2 / Cardiac Examination 2

Cardiac Examination Technique Perform auscultation in a quiet room with a calm patient. Place the patient in a standing or sitting position. Avoid listening to recumbent animals, as the change in heart position and configuration leads to errors. The flat diaphragm is used to detect high-frequency sounds (e.g., normal heart and breath sounds, most murmurs), while the bell is used to detect lower-frequency sounds (e.g., 3rd and 4th heart sounds, diastolic murmurs). The entire heart is examined, paying particular attention to the cardiac valves. Begin by placing the diaphragm gently but firmly at the left apex, where the first heart sound is best heard and also the location of the mitral valve. From here, inch the stethoscope to the left base of the heart, which is approximately 2 rib spaces cranial and slightly dorsal. Note the second heart sound and possible aortic and pulmonic stenosis murmurs. Next, palpate the right apex of the heart and move the stethoscope to this region. This is the tricuspid region and possible location of tricuspid regurgitation. Then move to the right base of the heart and observe for subaortic stenosis. Once an abnormality is noted, the surrounding region should be evaluated to find the point of loudest sound. In this process, the entire heart region should be evaluated and a complete examination given. Rate • Canine: 70–180 beats/min • Feline: 110–220 beats/min

Heart Sounds

Heart Valves

Normal

Normal

• First heart sound (S1) • Location: left apex of the heart • Sound: low-frequency sound longer than S2

• Pulmonic • Location: left 2nd–4th intercostal space above the sternal border

• Second heart sound (S2) • Location: base of the heart • Sound: high-frequency sound shorter than S1 • Third heart sound (S3) • Location: apex • Sound: low-intensity sound shortly after S2 • Fourth heart sound (S4) • Location: apex • Sound: low-intensity sound slightly before S1

30

SECTION TWO: PREVENTATIVE CARE

• Aortic • Location: left 3rd–5th intercostal space at mid-thorax • Mitral • Location: left 4th–6th intercostal space just above the sternal border, the apex of the heart • Tricuspid • Location: right 6th–7th intercostal space at mid-thorax, the apex of the heart

Abnormal • Murmurs Characterized by their location (over which valve they are the loudest), intensity (grade 1/6), frequency (harsh, blowing, musical, honking, or grunting), timing (point in the cardiac cycle the murmur is best heard), and quality (character/behavior).

Rhythms

Description of intensity

• Ventricular premature contractions (VPCs)

• • • • •

Grade 1: barely audible and localized Grade 2: soft and localized, but easily auscultated Grade 3: moderate loudness and evident in more than 1 location Grade 4: loud with palpable thrill and radiates Grade 5: very loud with palpable thrill, audible with stethoscope barely touching thorax • Grade 6: very loud with palpable thrill, audible when the stethoscope is removed from the thorax

• Gallop • Often seen during tachycardia when all four heart sounds are clearly heard. The combination of sounds is similar to the sound of a horse galloping. The rhythm is often heard with congenital heart disease, more specifically with hypertrophic cardiomyopathy in cats. • VPCs interrupt the normal sinus rhythm with a beat that is closer to the previous beat than normal followed by a compensatory pause. Patients often also have pulse deficits. • Atrial fibrillation • Rapid, but totally erratic rhythm with a clunking sound and varying intensity of the first and second heart sounds. Patients often have pulse deficits and variable pulse quality. Artifacts • Panting and excessive thoracic pressure in small patients similar to murmurs • Skin twitching similar to extra heart sounds • Friction from chest piece rubbing across fur similar to crackles

Tip: Ventilation artifacts can be discouraged by holding the mouth shut, whistling, or briefly obstructing a nare. Purring may be controlled with a visual distraction (e.g., visualization of water, another animal), blowing short bursts in air in their face, picking up the cat, or gently pressing over the larynx. Tip: When locating heart valves, count the ribs from caudal to cranial. Tip: The pulse and heart beat should be auscultated together and be synchronous. A heart beat without a pulse is a pulse deficit and may indicate an arrhythmia. Note: See Figures 1.9–1.12, Circulation, pages 9–10, and color plates 1.9, 1.10, and 1.12, pages CP-1, 2.

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2

Skill Box 2.3 / Pulmonary Examination 2

Pulmonary Examination Technique • Begin the examination by observing the respiratory effort (quality) and pattern and any signs of respiratory distress (e.g., nostril flare, intercostal rib retraction). After the initial assessment, perform auscultation in a quiet room with a calm patient. Place the patient in a standing or sitting position. Avoid listening to recumbent patients as it leads to errors due to changes in thoracic conformation. Divide the thoracic cavity into quadrants to follow a sequential pattern. As each quadrant is auscultated, it is observed for respiratory rate and breath sounds. Rate • Canine: 10–30 breaths/min • Feline: 25–40 breaths/min Breath Sounds • Should be heard equally on both sides of the thorax. Breath sounds heard outside the location defined below can be indicative of a medical problem. The normal respirations of canines can be heard throughout inspiration and during the first 1/3 of expiration. Only during inspiration can normal lung sounds be heard in a cat. Normal • Bronchial: • Location: center of the chest cavity over caudal trachea and larger bronchi • Sound: intense and harsh sounds, full inspiratory and expiratory phase with a louder inspiratory phase • Bronchovesicular: • Location: surrounding the bronchial region • Sound: intermediate sounds representing a combination of bronchial and vesicular sounds, full inspiratory phase with a short and quieter expiratory phase. • Vesicular: • Location: periphery of thoracic cavity • Sound: softer sound (e.g., wispy, rustling of leaves), inspiratory phase is slightly longer and louder than expiratory phase.

Abnormal • Stertor: • Location: larynx or trachea • Sound: discontinuous low-pitched snoring sound heard mainly on inspiration • Cause: tissue or secretions transiently obstruct airflow (e.g., elongated soft palate) • Stridor: • Location: larynx or thoracic inlet, referred sounds maybe heard throughout the thorax • Sound: intense continuous high pitched wheezes heard on inspiration • Cause: upper airway obstruction • Crackles (rales): • Location: over chest • Sound: discontinuous popping sound heard mainly on inspiration; defined as fine, medium, or coarse • Cause: fluid or exudate accumulation within airways or inflammation and edema in pulmonary tissue • Rhonchi or wheezes: • Location: isolated or variable • Sound: continuous musical sounds, low or high pitched heard at the end of inspiration or beginning of expiration; defined as high pitched or low pitched • Cause: ↓ airway lumen diameter

Tip: Listen to the lung sounds before listening to heart tones because the ear is much less sensitive to softer sounds once it has adjusted to louder sounds.

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SECTION TWO: PREVENTATIVE CARE

Skill Box 2.4 / Abdominal Examination

Abdominal Examination Technique • Gentleness when palpating an animal is essential as internal structures may be damaged if handled roughly. Structure descriptions can be: doughy (soft tissue that can be impressed with fingertips), firm (normal organ), hard (bones), fluctuant (soft, elastic, and undulates under pressure). Abnormalities noted on palpation are the following: pain, abnormal structures and their size, consistency, and shape, and location. • Large canine • Place the patient in a standing position. Stand on either side or to the rear. Place 1 hand on either side of the abdomen in a flat and relaxed position. Begin at the spine and gently and slowly move ventrally, allowing the abdominal viscera to slip through the fingers. Repeat this process throughout the abdomen moving caudal. • Small canine or feline • Place the patient in a standing position. Stand next to the patient. Cup 1 hand around the abdomen with the thumb on 1 side and the fingers on the other side in a flat and relaxed position. Begin at the spine and gently and slowly move ventrally, allowing the abdominal viscera to slip through the fingers. Repeat this process throughout the abdomen moving caudal.

• Internal structure location • Cranial abdomen • Palpation of the liver, spleen, and the small intestines • Liver is difficult to palpate and extension past the costal arch may indicate hepatomegaly. • Spleen is difficult to palpate and recognition may indicate splenomegaly. • Normal stomach is rarely palpable, but with overeating (doughy or fluid-filled) or gastric distention it may be felt. • Mid-abdomen • Palpation of the small intestines, kidneys, and spleen • Right kidney is more cranial than the left kidney in cats and may be obscured by the ribs. • Mesenteric lymph nodes are difficult to palpate unless enlarged. • Caudal abdomen • Palpation of the colon, uterus, bladder, prostate, and small intestine • Feces can be discerned from a mass by its deformability with fingertip imprints. • Prostate can occasionally be palpated central to the colon and caudal to the bladder.

Note: See Figures 1.6–1.8, Internal Organs, page 8, and Color Plates 1.6–1.8, pages CP-1.

Skill Box 2.5 / Otoscopic Examination

Otoscopic Examination Technique • Examine the good ear first to avoid spread of infection and to decrease resistance to examination of the possibly more painful ear. Begin with an otoscope with the appropriate sized cone for the patient. For ease of examination, the patient should be placed on a table or large canines should be placed in a sitting position. The head should be held in such a manner to avoid crushing the ear canal while directing the

muzzle toward the thoracic inlet. Holding the pinna up and out from the base of the skull will allow straightening of the ear canal. Gently insert the otoscope into the external ear canal and slowly advance while observing the canal. As the cone enters the vertical canal, the pinna is pulled up and over the otoscope while the otoscope handle is rotated to a horizontal position. The tympanic membrane will then be visualized in a normal ear as a white translucent membrane. Any abnormalities such as: inflammation, redness, exudate, foreign objects, mites, or tumors should be noted.

Note: See Figure 1.19, Ear, page 13.

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33

2

Skill Box 2.6 / Regional Lymph Node Examination 2

Regional Lymph Node Examination Technique • Three pairs of lymph nodes are routinely palpated in a normal animal; submandibular, prescapular, and popliteal. Axillary and inguinal nodes can often only be palpated with enlargement. Peripheral lymph nodes should be palpated simultaneously to evaluate symmetry. Enlarged nodes may be an initial indicator of a problem. Lymph nodes are generally smooth and oval in shape and can be most easily felt by grabbing the skin and allowing it to slip through the fingertips while pulling the hands away. • Submandibular • Location: ventral to the angle of the mandible, cranial to the parotid and submaxillary salivary glands • Size: group of 2 or 3 nodes pea to grape size

• Prescapular (superficial cervical) • Location: in front of the cranial border of the scapula • Size: group of 2 or 3 nodes slightly larger than submandibular nodes • Popliteal • Location: caudal to the stifle • Size: 1 node about the size of a pea; not always palpable in smaller animals • Axillary • Location: caudal and medial to the shoulder joint • Size: 1 or 2 nodes; not palpable in normal animals (0.5–10 mm) • Inguinal • Location: furrow between the abdominal wall and the medial thigh • Size: 2 nodes, not palpable in normal animals (0.5–10 mm)

Note: See Figure 1.2, Regional Lymph Nodes, page 6.

Skill Box 2.7 / Neurologic Examination

Neurologic Examination Technique • The neurologic examination begins as the patient walks into the examination room. Notice should be paid to the patient’s body posture (e.g., head tilt), attitude (e.g., demented, semicomatose, disoriented) and gait (e.g., inability or abnormal walk, dragging limbs, circling), purposeful movement (e.g., attempt to move down limbs), and palpation (e.g., symmetry, worn toenails, ↑ or ↓ muscle tone, masses).

Postural Reactions

Spinal Reflexes

• The patient’s ability to recognize an abnormal position and change its position to bear weight and be able to walk. All levels of the nervous system are evaluated, but lesion localization is not possible.

• Deficits in spinal reflexes alert to a problem along the nerve pathway; receptor, sensory nerve, efferent nerve, and skeletal muscles. Responses seen may be normal, absent, depressed or exaggerated.

• Extensor postural thrust

• Anal sphincter reflex

• While supporting the patient under the thorax, as the hindlimbs touch the floor, monitor for symmetric caudal walking motions. • Hemistanding/hemiwalking • A hindlimb and front limb of the same side are lifted, monitor for lateral walking movements. 34

SECTION TWO: PREVENTATIVE CARE

• Perineal stimulation with a needle or forceps; monitor for contraction of the anal sphincter muscle. • Panniculus reflex • Pin prick stimulus to skin over the back; monitor for twitching of cutaneous trunci muscles on both sides.

Skill Box 2.7 / Neurologic Examination (Continued) • Hopping • While supporting the patient, 3 limbs are lifted and the patient is moved medially and laterally, monitor for initiation and movement of hopping. • Placing • While supporting the patient under the thorax, the thoracic limbs are brought in contact with the edge of a table; immediate placement of the limbs on top of the table is expected. • This is done twice, once with the eyes covered and once with the eyes opened. • Proprioceptive positioning • While supporting the patient, turn the hind foot over onto the dorsal surface and monitor the length of time to turn it back to a normal position, if even able. • Wheelbarrowing • While supporting the patient under the abdomen with the hindlimbs lifted, monitor the length of time to start walking forward and the walking coordination.

Hindlimb Reflexes • Cranial tibial response • Percuss muscle belly; monitor for flexion of the hock. • Crossed extensor reflex • Pinch digits of down limb; monitor for involuntary movement of upper limb. • Gastrocnemius reflex • Percuss Achilles tendon; monitor for extension of the hock. • Patellar reflex • Patient in lateral recumbency and stifle gently supported in a flexed position, percuss patellar tendon; monitor for extension of the stifle. • Sciatic response • Percuss thumb in the sciatic notch; monitor for jerk of the entire limb. • Withdrawal • Patient in lateral recumbency. pinch digits; monitor for flexion of the limb and pain recognition.

Front Limb Reflexes • Extensor carpi radialis response • Percuss the extensor carpi radialis muscle; monitor for extension of the carpus. • Triceps reflex • Patient in lateral recumbency with limb supported, elbow fully extended and leg caudal, percuss the triceps tendon: monitor for slight extension of the elbow. • Withdrawal • Patient in lateral recumbency, pinch digits; monitor for flexion of the limb and pain recognition.

Sensory Evaluation

Cranial Nerves

• Evaluation of deep pain perception • Hyperpathia • Pressure is applied along the thoracic and lumbar regions to the spine and muscles at each vertebra; monitor for a behavioral response to pain • Sensory level • Pin prick stimulus to skin over the back, monitor for behavioral response

• The following cranial nerves (CN) are evaluated with a suspected brain lesion • Optic nerve (CN II): vision, menace response • Oculomotor nerve (CN III): pupillary light response, size and symmetry • Trochlear nerve (CN III, IV, VI): eye movements • Trigeminal nerve (CN V, VII): muscle mass, jaw tone, facial movements, blinking, lip retraction • Vestibulocochlear nerve (CN VIII): hearing • Glossopharyngeal and vagus nerves (CN IX, X, XI): pharyngeal sensation, gag response • Hypoglossal nerve (CN XII): tongue movement and strength CHAPTER 2 / PREVENTATIVE CARE AND VACCINATIONS

35

2

Skill Box 2.8 / Orthopedic Examination 2

Orthopedic Examination Technique • Similar to the neurologic examination, the orthopedic examination begins as the patient enters the examination room. Notice should be paid to the patient’s conformation, stance, sitting, standing, rising and gait. The examination should continue with a hands-on evaluation of the area of concern, including the alternate side. A systematic approach should be used to cover the entire limb, often beginning distally and moving proximal. Alterations in range of motion and rotation should be noted along with any crepitus, clicking, clunking, instability, swelling, muscle atrophy or overdevelopment, and pain. Begin the examination by evaluating the nonaffected joint to assess the patient’s normal response to manipulation and pressure.

Stifle

Pelvis

• Cranial drawer motion

• Barden’s procedure

• Patient in lateral recumbency, 1 hand stabilizes the femur proximal to the stifle. The second hand is placed with the thumb behind the fibular head and the index finger over the tibial crest. With the femur stabilized, the second hand moves the tibia cranial and distal in a plane parallel to the tibial plateau. Monitor for the tibia sliding cranially or caudally in relationship to the femur indicating cruciate ligament rupture or partial tear. • Test should be performed with the stifle joint in extension, 90º flexion, and normal standing position. • Tibial compression test • Limb is held in a standing position, the hock is flexed to tense the gastrocnemius muscle which compresses the femur and tibia together; monitor for forward motion of the tibia in a ruptured cranial cruciate ligament. • Patellar luxation, medial • Limb is held extended with the foot rotated internally, digital pressure is applied medially; monitor for medial displacement indicating luxation. • Patellar luxation, lateral • Limb is held slightly flexed with the foot rotated externally, digital pressure is applied laterally; monitor for lateral displacement indicating luxation.

• Patient in lateral recumbency, grasp the femur with 1 hand. Place the thumb of second hand on the greater trochanter of the femur, while resting the rest of your palm on the pelvis. With gentle pressure, attempt to lift the femur, keeping it parallel to the table. Monitor for subluxation of the femur through the thumb on the greater trochanter indicating hip laxity. • Barlow’s sign • Patient in dorsal recumbency with stifle flexed, the left hand is placed on the right stifle and slowly adducted, monitor for luxation of the femoral head from the acetabulum indicating joint capsule stretching. • Hip luxation • Patient in a standing position, place the thumb in the space caudal to the greater trochanter, externally rotate the femur; monitor for the trochanter to roll over the thumb indicating luxation. • Ortolani maneuver, lateral recumbency • Limb is held in a standing position parallel to the table surface. One hand is placed over the hip joint, the other hand cups the stifle joint to apply pressure pushing the femoral head in a dorsal direction in relation to the acetabulum. Monitor for hip subluxation indicating hip laxity. • Ortolani maneuver, dorsal recumbency • Stifles are positioned parallel to each other and perpendicular to the table. Downward pressure is applied on the stifles to subluxate the hip. Maintain pressure and abduct the stifle. Monitor for hip subluxation indicating hip laxity.

36

SECTION TWO: PREVENTATIVE CARE

VACCINATIONS Young animals receive a small amount of natural immunity from their mother’s milk, exchanged in the form of colostrum, during the first few days of nursing. However, this temporary maternal protection wanes by 6–9 weeks. To continue and enhance this protection, vaccinations are available to protect the animal from contracting various highly contagious diseases. These diseases and their corresponding vaccinations are charted on the following pages. Vaccines in general are meant to be stored in the refrigerator, and need to be shaken well before dispensing. Lyophilized vaccines should be used within 30 minutes of reconstitution. Heat, excessive cold, and light exposure can inactivate the vaccine and make them ineffective.

Guidelines to Follow When Vaccinating an Animal • A complete physical examination and health evaluation are given by a veterinarian before any vaccination.

Adverse reactions: As with the administration of any drug, vaccines can result in adverse reactions. Possible reactions range from sensitivity at the injection site, a small bump or knot at the injection site, slight fever, hives, lethargy, and anaphylactic shock (vomiting, salivation, dyspnea, and incoordination). Precautions should be taken in animals with a history of vaccine reactions. Vaccines should be avoided if possible, but if they must be given the following guidelines should be observed: • A vaccine from a different manufacturer • Premedication with diphenhydramine and prednisolone sodium succinate 30 minutes prior to the vaccination • Hospital observation for the day Clients should be educated to monitor vaccination sites for lump formation and contact their veterinarian if found. Biopsies should be taken following the AAFP guidelines: • Present for 3 months

• Do not vaccinate pregnant animals with a modified live vaccine.

• ≥2 cm in diameter

• Animals with a fever or in debilitated health should not be vaccinated until healthy.

• ↑ Size after 1 month

As a constant effort to increase patient bonding and improve client satisfaction, special steps can be taken to ensure patient and owner comfort. Taking the extra steps to make this a more enjoyable experience will benefit both the patient and staff in future visits. A few tips for making injections a more comfortable procedure include: • Allowing the vaccine to warm to room temperature • Changing needles before injection; use of a 25-gauge needle • Gently squeezing or flicking the injection site to dull the area • Distracting the patient (e.g., treats, sliding the patient across the table or lifting their front legs, twitching a ear or tapping the nose, talking to the patient).

Titers: The discussion of vaccine titers has become very popular in veterinary medicine, and continues to remain controversial. Titers are available from various laboratories for distemper, parvovirus, rabies, and panleukopenia. If a titer is high, it is accepted as providing protection; however a low titer result does not reflect the immunization of an animal. Titers are best used following the puppy vaccine series to ensure proper levels of immunity have been reached. As each animal and its environment are unique, vaccine recommendations will vary accordingly at the discretion of the veterinarian and in accordance with state laws.

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2

Table 2.6 / Canine Transmissible Diseases: Coronavirus, Distemper Distemper

Definition

Contagious viral disease affecting the GIT, resulting in sporadic outbreaks of vomiting and diarrhea. Diarrhea is caused by the virus invading the enterocytes of the villous tips.

An acute to subacute febrile and often fatal, highly contagious viral disease with respiratory, GIT, and central nervous system (CNS) manifestations.

Presenting Clinical Signs

• Most infected dogs are asymptomatic and less signs are exhibited in adult dogs • Anorexia, depression, diarrhea (yellow-green to orange, malodorous) and vomiting

• Mucosal phase: malaise, nasal discharge followed by pneumonia, vomiting, diarrhea and fever • CNS phase: seizures, circling, pacing, ataxia and paresis

Examination Findings

• Dehydration, mild respiratory effects

• Abdominal pustules, anterior uveitis, conjunctivitis, dental enamel hypoplasia, hyperkeratosis of foot pads, KCS, myoclonus, optic neuritis, retinal degeneration and rhinitis

General

• History/clinical signs

• History/clinical signs

Laboratory

• Electron microscope • Fluorescent antibody tests

• CBC: lymphopenia, leukopenia, thrombocytopenia in early disease • Fluorescent antibody test: detection of virus in intact cells (e.g., conjunctival scrapings, buffy coat, urine sediment, CSF, transtracheal wash) • IgM: serum antibodies measured by ELISA • IgG: serial titers on 2 serum samples 2 weeks apart to detect ↑ titers • PCR: virus detection in respiratory secretions, CSF, feces and urine

Imaging

• N/A

• Thoracic: interstitial or alveolar pneumonia

Procedures

• N/A

• N/A

General

• Symptomatic • Supportive • Fluid therapy

• Supportive • Fluid therapy

Medication

• Imodium

• • • •

Antibiotics B vitamin supplementation Anticonvulsant therapy Antiemetics

Nursing Care

• N/A

• • • • •

Humidification of airways; nebulization and coupage Clean discharge from eyes and nose Nutritional support Adequate fluid intake or therapy Isolation to avoid infecting other patients

Diagnosis

Presentation

Coronavirus

Treatment

2

Disease

38

SECTION TWO: PREVENTATIVE CARE

Table 2.6 / Canine Transmissible Diseases: Coronavirus, Distemper (Continued)

Follow-Up

Disease

Coronavirus

Distemper

Patient Care

• N/A

• Monitor dehydration and electrolytes. • Recheck thoracic radiographs if persistent cough.

Prevention/Avoidance

• Vaccinate • Clean up feces: Will be shed in the feces for typically 6–9 days; but can be for many months

• Vaccinate • Avoid infected dogs or wildlife. • Clean up feces: shedding time typically < 2–3 months

Complications

• Persistent diarrhea for 10–12 days • Dehydration and electrolyte imbalances

• Occurrence of CNS signs may appear for up to 2–3 months after clinical signs • Seizures or CNS signs

Prognosis

• Complete recovery expected

• Ranges from subacute to mortality • Mortality rate of 50%

• Optional part of vaccine series • Consider vaccinating high-risk dogs: field trial dogs and kenneled dogs • Transmitted by fecal-oral route

• Unvaccinated puppies 6–12 weeks of age are most at risk. • Transmitted through body secretions, body excretions, and airborne • Easily destroyed by heat and most disinfectants; survives no more than a few days outside the host • Recovered dogs are not carriers. • Incubation period: 1–5 weeks

Notes

2

Table 2.7 / Canine Transmissible Diseases: Hepatitis, Infectious Tracheobronchitis Hepatitis

Infectious Tracheobronchitis

Definition

Viral disease caused by adenovirus type 1. Affects the liver, eyes, and endothelium

Contagious respiratory disease often caused by the bacteria Bordetella bronchiseptica resulting in the harsh, hacking coughing. It can also be caused by the viruses parainfluenza and canine adenovirus 2.

Presenting Clinical Signs

• Coma, depression, diarrhea, disorientation, lethargy, seizures, stupor, vomiting

• Mild form: repetitive dry-sounding hacking cough (referred to as “seal-like”) often followed by gagging and mild serous naso-ocular discharge • Severe form: anorexia, depression, naso-ocular discharge and productive cough

Examination Findings

• Abdominal pain, anterior uveitis, corneal edema, fever, hemorrhagic diathesis, hepatic encephalopathy, hypoglycemia, pale mucous membranes, nonsuppurative encephalitis, tonsillitis-pharyngitis

• Fever

Presentation

Disease

CHAPTER 2 / PREVENTATIVE CARE AND VACCINATIONS

39

Table 2.7 / Canine Transmissible Diseases: Hepatitis, Infectious Tracheobronchitis (Continued) Disease

Diagnosis

2

Hepatitis

Infectious Tracheobronchitis

General

• Clinical signs

• Cough easily elicited on palpation of trachea • History of frequenting boarding facilities or off-leash parks

Laboratory

• • • •

• CBC: mild leukopenia, neutrophilic leukocytosis with a left shift • Cultures of nasal swabs, transtracheal or bronchial washings: Bordetella and Mycoplasma • PCR: virus detection

Imaging

• Radiographs, abdominal: hepatomegaly • Ultrasound: hepatomegaly and abdominal effusion

• Abdominal, thoracic: severe form, interstitial density, and alveolar pattern

General

• Symptomatic • Supportive • Fluid therapy +/− potassium and dextrose supplementation

• Supportive

Medication

• Antibiotics for secondary pneumonia or pyelonephritis

• Antibiotics • Bronchodilators • Antitussives

Nursing Care

• Frequent feedings to avoid hypoglycemia • Restricted activity/cage rest

• • • • • •

Patient Care

• Monitor blood chemistries • Monitor dehydration, acid-base balances, body weight, physical assessment, and electrolytes

• Adequate fluid intake • Airway humidification • Strict rest for 14–21 days

Prevention/Avoidance

• Vaccinate • Avoid urine contact: shedding time, 6 months or more

• • • •

Complications

• • • •

• N/A

Prognosis

• Guarded to good • Some with a complete recovery

• Complete recovery expected unless severe disease develops

• Transmitted through oronasal exposure and shed in all secretions during acute infection • Shed for 6–9 months following recovery • Highly resistant to inactivation and disinfection, thus enabling spread by fomites and ectoparasites

• Highly contagious via aerosol spread and fomites • Disinfect with bleach, Nolvasan, or Roccal. • Incubation period: 3–10 days

CBC: neutropenia, lymphopenia and thrombocytopenia Chemistry panel: ↑ AST, ALT and ↓ glucose Bile acids: mild to moderately high Coagulation tests: prolonged PT, APTT, hypofibrinogenemia

Follow-Up

Treatment

Procedures

Notes

40

Hepatic failure or chronic active hepatitis Acute renal failure DIC Glaucoma

SECTION TWO: PREVENTATIVE CARE

Encourage outpatient care for uncomplicated disease. Airway humidification Strict confinement with low stress, and few dogs Nutritional support ↑ Fluid intake Fresh air flow

Vaccinate Prevent fomite spread with bleach diluted 1:32. Isolate infected animals. Shed for up to 3 months, infectious risk is greatly ↓ after recovery of discharge and cough.

Table 2.8 / Canine Transmissible Diseases: Leptospirosis, Lyme Disease Leptospirosis ZOONOTIC

Lyme Disease ZOONOTIC

Definition

Acute and chronic bacterial disease affecting lungs, kidneys, and liver

A multiorgan disease caused by the spirochete Borrelia burgdorferi

Presenting Clinical Signs

• Anorexia, dehydration, depression, myalgia, reluctance to move and vomiting

• Anorexia and lethargy

Examination Findings

• Acute renal or hepatic failure, conjunctivitis, DIC, epistaxis, fever, melena, petechia, poor capillary perfusion, rapid irregular pulse, tachypnea

• Fever, lymphadenopathy, and polyarthritis

General

• Clinical signs

• Joint palpation: lameness, swelling, and pain • History of travel in known tick infested areas

Laboratory

• CBC: leukopenia, thrombocytopenia, and neutrophilia with left shift • Chemistry panel: ↑ BUN, creatinine, AST, ALT, ALP, bilirubin, phosphorus, ↓ chloride, sodium, and potassium • Urinalysis: proteinuria, pyuria, bilirubinuria, and isothenuria • Microscopic agglutination test: + after 1 week, peaking at 3–4 weeks, fourfold rise in titer • Combined IgM-IgG ELISA titers: IgM is + in first week and persists to 2 weeks; IgG is + 2–3 weeks after infection and persists for months

• • • •

Imaging

• N/A

• Radiographs, joints: +/− effusion

Procedures

• N/A

• N/A

General

• Supportive • Fluid therapy • Transfusion therapy

• Supportive

Medication

• Antibiotic: doxycycline, penicillin (leptospiremia)

• Antibiotics: tetracycline, ampicillin, doxycycline, and cephalexin • NSAIDs

Nursing Care

• Restrict activity/cage rest. • Nutritional support

• Encourage outpatient care. • Pain management

Treatment

Diagnosis

Presentation

Disease

IDEXX SNAP 3Dx test IDEXX SNAP 4Dx test IFA and ELISA: ≥1:152 = highly + Synovial fluid analysis: suppurative and +/− Borrelia organisms within WBC

CHAPTER 2 / PREVENTATIVE CARE AND VACCINATIONS

41

2

Table 2.8 / Canine Transmissible Diseases: Leptospirosis, Lyme Disease (Continued) Disease

Follow-Up

2

Leptospirosis ZOONOTIC

Lyme Disease ZOONOTIC

Patient Care

• Monitor blood chemistries and urinalysis.

• Restricted activity

Prevention/Avoidance

• Vaccinate in high-risk areas. • • Avoid water sources where animals may have urinated; shedding time, months • to years. • •

Complications

• DIC • Permanent renal and hepatic dysfunction

• CNS disorders • Fatal renal failure • Heart block (rare)

Prognosis

• Most infections are subclinical; those that are acutely severe have a guarded prognosis.

• Recovery expected, but recurrence possible within weeks to months

• Spread in the urine of recovered animals for months to years following infection • Transmitted by food, water, bedding, soil, vegetation, or fomites • Disinfect with povidine-iodine; bleach 1:10 dilution. • Enters through skin or mucous membranes or by ingestion of contaminated water • Onset is a few days to 30 days; typically 3–14 days.

• Transmitted most commonly by the deer tick Ixodes dammini through a tick bite. • Infected animals pose little risk to humans; they are more of a risk in passing ticks to humans.

Notes

Limit access to tick-infested areas. Use tick repellants/insecticides. Periodically check dogs for ticks. Vaccinate in high-risk areas.

Table 2.9 / Canine Transmissible Diseases: Parvovirus, Rabies Parvovirus (CPV)

Rabies ZOONOTIC

Definition

Highly contagious disease causing severe enteritis and affecting the lymphatic system. Typically affects puppies between weaning and 6 months of age.

A virus that can infect almost all warm-blooded animals and is considered untreatable. It infects the nervous system, causing death from paralysis.

Presenting Clinical Signs

• Anorexia, depression, and vomiting • Diarrhea: profuse, liquid, hemorrhagic, and distinct metallic odor • Symptoms may vary in older dogs.

Three phases • Prodromal phase (2–3 days): fever, subtle behavior changes • Furious phase (2–4 days): irritability, restlessness, barking, ataxia, and seizures • Paralytic phase (2–4 days): paralysis, depression, coma, and death from respiratory paralysis

Examination Findings

• Extreme dehydration, fever

• Prodromal phase: slow corneal and palpebral reflexes

Presentation

Disease

42

SECTION TWO: PREVENTATIVE CARE

Table 2.9 / Canine Transmissible Diseases: Parvovirus, Rabies (Continued) Parvovirus (CPV)

Rabies ZOONOTIC

General

• History/clinical signs

• History/clinical signs

Laboratory

• CBC: severe leukopenia and lymphopenia, PCV variable • Chemistry panel: ↑ bilirubin, ALT, AST and ↓ potassium, sodium and chloride • ELISA assay • IDEXX Parvo Antigen SNAP test • Fecal hemagglutination test

• CSF: minimal ↑ protein and leukocytes • Postmortem virus isolation from fresh brain tissue

Imaging

• Radiographs, abdominal: gas and fluid distention in GIT • Often causing a misdiagnosis of GIT obstruction

• N/A

Procedures

• N/A

• N/A

General

• Symptomatic • Supportive • Fluid therapy: aggressive

• Supportive

Medication

• Antibiotics: ampicillin and gentamicin • Antiemetics: metoclopramide or H2 blocker

• N/A

Nursing Care

• Nothing by mouth for 24 hours after vomiting and severe diarrhea • Quarantine protocol

• Strictly inpatient/quarantine • Runs and cages should be locked.

Patient Care

• Dogs should remain isolated for 1 week after complete recovery.

• None

Prevention/Avoidance

• Vaccinate out to 16–18 weeks • Isolate puppies as much as possible until vaccine series has been completed.

• Vaccinate • Strict quarantine for those suspected of having rabies • Euthanize all animals known to have rabies

Complications

• Septicemia • Secondary bacterial pneumonia • Intussusception

• N/A

Prognosis

• Survival of 3–4 days is usually followed by rapid recovery. • Immunity by natural infection is lifelong if the dog survives.

• Almost 100% fatal

• Transmitted by the fecal-oral route, saliva, vomitus, or direct contact • Stable in the environment for months to years • Rottweilers, Doberman Pinschers, Pit Bull Terriers, and Labrador Retrievers seem to be at higher risk. • Disinfect with 1:32 dilution of bleach and water or Parvocide®. • Incubation period 5–10 days

• Transmitted in the saliva • Inactivated by disinfectants • Head should be chilled on wet ice (do not freeze) and sent to a lab for analysis.

Follow-Up

Treatment

Diagnosis

Disease

Notes

CHAPTER 2 / PREVENTATIVE CARE AND VACCINATIONS

2

43

Table 2.10 / Canine Vaccination Protocol

The site of vaccine injection varies between clinics, but it is important to have a designated location for each vaccine and to note these locations in each patient’s chart. Vaccines are routinely given subcutaneously, except for the intranasal version of Bordetella. Vaccine

≤16 Weeks of Age

>16 Weeks of Age

Vaccine Classificationa

DHPP • Canine distemper (D) • Canine hepatitis/adenovirus (H) (CAV-2) • Canine parainfluenza (P) • Canine parvovirus (P)

• 1 dose at 6–9 weeks, then repeat every 3–4 weeks until 16 weeks (e.g., 1 dose at 8, 12 and 16 weeks) • 1 dose at 12 months, then every 3 years

• 1 dose initially • 1 dose 12 months after initial, then 1 dose every 3 years

Core Core

Leptospirosis • Canine leptospirosis

• 1 dose: 12 and 16 weeks • Annually dependent on patient’s risks

• 2 doses, 2–4 weeks apart • Annually dependent on patient’s risks

Noncore

Bordetella • Infectious tracheobronchitis

• IN: 1 dose at 3–12 weeks, then 1 dose 2–4 weeks later, then biannually or annually dependent on patient’s risks • SQ: 1 dose at 6–8 weeks, repeat 1 dose 2–4 weeks later, then annually dependent on patient’s risks

• IN: 2 doses, 2–4 weeks apart, then biannually or annually dependent on patient’s risks • SQ: 1 dose, then biannually or annually dependent on patient’s risks

Noncore

Rabies • Rabies virus

• 1 dose at 12–16 weeks • 1 dose every 1–3 years dependent on vaccine type and state requirements

• 1 dose initially • 1 dose every 1–3 years dependent on vaccine and state requirements

Core

Lyme • Lyme borreliosis

• 1 dose at 9–12 weeks, then repeat 2–4 weeks later • Annually, dependent on patient’s risk

• 2 doses, 2–4 weeks apart • Annually, dependent on patient’s risk

Noncore

Noncore Core

Note: Injection site, age at administration, and booster protocol may vary depending on the manufacturer of the vaccination and veterinarian’s discretion. Recommendations by the individual manufacturer should be followed. The frequency may vary depending on the state’s requirements and the veterinarian’s protocol. Note: Possible reactions range from sensitivity at the injection site, a small bump or knot at the injection site, slight fever, hives, and lethargy to anaphylactic shock (vomiting, salivation, dyspnea, and incoordination). a Core vaccines are those recommended to every dog. Noncore vaccines are recommended based on potential risk factors.

Table 2.11 / Feline Transmissible Diseases: Feline Calcivirus Disease

Feline Calicivirus (FCV)

Definition

One of the major causes of feline upper respiratory disease. An acute, highly contagious viral disease causing oral ulceration, pneumonia, and occasionally arthritis.

Presentation

2

44

Presenting Clinical Signs

Anorexia, depression, dyspnea, mild conjunctivitis, mild sneezing, nasal discharge, ulcerated tip of nose

Examination Findings

• +/− Arthralgia, enteritis, facial and limb edema, fever, gingivitis, limping syndrome, interdigital paw ulcers, oral ulcers

SECTION TWO: PREVENTATIVE CARE

Table 2.11 / Feline Transmissible Diseases: Feline Calcivirus (Continued)

Follow-Up

Treatment

Diagnosis

Disease

Feline Calicivirus (FCV)

2

General

• History/clinical signs

Laboratory

• CBC: neutrophilia and lymphopenia • Chemistry panel: ↑ bilirubin, CK • Virus isolation: cell cultures of swabs from oropharynx, lung tissue, nasal cavity, conjunctiva, feces, and blood

Imaging

• Radiographs, thoracic: generalized ↑ density of the lungs

Procedures

• N/A

General

• Self-limiting in 5–7 days • Supportive

Medication

• • • • •

Nursing Care

• Oxygen supplementation if complicated pneumonia • Nutritional support

Patient Care

• • • • •

Prevention/Avoidance

• Vaccinate • Prevent contact with FCV-infected cats. • Virus is shed continuously.

Complications

• Interstitial pneumonia • Secondary bacterial infections

Prognosis

• Excellent unless pneumonia develops • Recovered cats may shed the virus in their saliva for long periods.

Notes

Antibiotics: amoxicillin Antibiotic (ophthalmic) Pain medication Immunostimulants: interferon Corticosteroids

Keep eyes and nose clear of discharge. Support nutrition and fluid intake Airway humidification Provide soft foods if oral ulcers. Irrigate oral lesions with 0.2% chlorhexidine solution.

• Transmission is through direct contact and fomites; virus is shed in oropharyngeal, conjunctival, and nasal secretions, feces, sloughed hair and skin. • Very resistant virus; disinfect with 1:32 dilution of bleach water. • Cats that recover may remain subclinical carriers for months to years. • Cats should be tested for FIV or FeLV to rule out underlying immunodeficiency syndromes. • Occurs with FHV-1 in most cases. • Incubation period is 1–5 days. • Intermittent shedding may take place for 4 months postinfection.

CHAPTER 2 / PREVENTATIVE CARE AND VACCINATIONS

45

Table 2.12 / Feline Transmissible Diseases: Feline Infectious Peritonitis

Definition

A systemic viral disease with high mortality. This disease arises from a mutation of a benign virus, feline enteric coronavirus (FEVC) commonly found in the GIT of cats. There are 2 different forms: wet/effusive form and the dry/noneffusive, granulomatous form.

Presenting Clinical Signs

• Ataxia, behavioral changes, depression, diarrhea, failure to grow, inactivity, paresis, poor condition, seizures, urinary incontinence, vomiting, weight loss • Dry Form: dyspnea, exercise intolerance • Wet Form: abdominal distention

Examination Findings

• Fever, icterus, pallor • Dry form: anterior uveitis, chorioretinitis, iritis, irregular pupils, tumors • Wet Form: abdominal or pleural effusion

General

• Clinical signs after other conditions have been ruled out

Laboratory

• • • • • • •

Imaging

• Radiographs, thoracic: effusion • Radiographs, abdominal: effusion, organomegaly, lymphadenopathy, and ileocolic mass

Procedures

• Abdominocentesis or thoracocentesis; straw-colored fluid, viscous, clots, fibrinous, and ↑ protein • Tumor biopsy: granulomatous inflammation

General

• Therapeutic paracentesis • Fluid therapy • Supportive

Medication

• Corticosteroids: prednisone • Immunosuppressive drugs: cyclophosphamide • Immunostimulants: immunoregulin, interferon, acemannan

Nursing Care

• Nutritional support

Diagnosis

Presentation

Feline Infectious Peritonitis (FIP, Feline Coronavirus)

Treatment

2

Disease

46

SECTION TWO: PREVENTATIVE CARE

CBC: leukopenia (early in disease), leukocytosis with neutrophilia, lymphopenia (late in disease), nonregenerative anemia Chemistry panel: ↑ bilirubin, ALP, ALT, globulins and bile acids, BUN, creatinine Urinalysis: ↓ bilirubin and protein Histopathologic examination: biopsy is the only definitive method for FIP diagnosis Immunohistochemistry: most accurate FIP virus detection on biopsied tissue Titers: limited value, highest titers have ↑ likelihood of disease PCR: virus detection

Table 2.12 / Feline Transmissible Diseases: Feline Infectious Peritonitis (Continued)

Follow-Up

Disease

Feline Infectious Peritonitis (FIP, Feline Coronavirus)

Patient Care

• Confine to prevent exposure to other cats

Prevention/Avoidance

• • • •

Complications

• GIT obstruction • Neurologic disease • Pleural effusion

Prognosis

• Almost 100% mortality • Length of disease is a few days to months.

Notes

2

Prevent contact with FIP-positive cats; transmission is rare between cats. Intranasal vaccine; very low efficacy Routine disinfection Control and prevent feline leukemia virus (FeLV) infection.

• Transmitted through oral and respiratory secretions, feces, urine, and fomites, but most commonly through the mutation of FECV to FIP • Survives in the environment for several weeks • Readily inactivated by commonly used disinfectants

Table 2.13 / Feline Transmissible Diseases: Feline Panleukopenia Virus, Feline Immunodeficiency Virus Feline Panleukopenia Virus (FPV, Feline Parvovirus)

Feline Immunodeficiency Virus (FIV)

Definition

An acute, systemic, and enteric viral disease. It has a sudden onset, is highly contagious, and has a high mortality rate.

An immunodeficiency syndrome characterized by chronic and recurrent infection. Gradually selecting and destroying T-lymphocytes. This process makes cats more prone to secondary syndromes. Affected cats can be asymptomatic for >5years.

Presenting Clinical Signs

• Abdominal pain (crouching position and head between front paws), anorexia, depression, diarrhea, persistent vomiting, rough and dull hair coat

Stage 1 • Usually subclinical: fever, neutropenia, and lymphadenopathy Stage 2 • Latent phase: could last for years Stage 3 • Terminal phase: abscesses, anorexia, cachexia, dementia

Examination Findings

• Fever progressing to hypothermia and progressive dehydration

• Conjunctivitis, gingivitis, otitis, periodontitis, pneumonia, rhinitis, skin infections, stomatitis, tachycardia, urinary tract infections

Presentation

Disease

CHAPTER 2 / PREVENTATIVE CARE AND VACCINATIONS

47

Table 2.13 / Feline Transmissible Diseases: Feline Panleukopenia Virus, Feline Immunodeficiency Virus (Continued) Disease

Feline Immunodeficiency Virus (FIV)

General

• History/clinical signs

• History/clinical signs of exposure

Laboratory

• CBC: leukopenia • Chemistry panel: ↑ BUN, creatinine, and electrolyte imbalances • Virus isolation: feces • CITE test for canine parvovirus: detects FPV antigen in the acute stage • Serologic testing: rising titers • Chromatographic test strip, feces: + for FPV and CPV

• • • • • •

Imaging

• N/A

• N/A

Procedures

• N/A

• N/A

General

• Supportive • Fluid therapy • Blood transfusions

• Symptomatic • Fluid therapy • Dental care

Medication

• Antibiotics • Antiemetics: metoclopramide

• • • •

Nursing Care

• Nothing by mouth until vomiting and diarrhea subside • Heat support if hypothermic • Monitor hydration, electrolytes, and CBC

• Nutritional support

Patient Care

• Heat support • Nutritional support once eating

• Maintain current vaccines to prevent infection of respiratory disease

Prevention/Avoidance

• Vaccinate. • Prevent contact with infected cats. • Clean up feces: shedding time up to 6 weeks

• • • •

Complications

• • • •

• N/A

Prognosis

• Poor prognosis in terminal phase: ≤1 year survival

• >50% remain asymptomatic within 2 years after diagnosis • Poor prognosis in terminal phase: ≤1 year survival

• Transmitted by fomites and through all body secretions for up to 6 weeks. • Disinfect with 1:32 dilution of bleach water. • Survives months to years in the environment • In utero transmission from infected queen leads to cerebellar hypoplasia in kittens. • Incubation period: <14 days • Recovered cats have lifetime immunity against FPV.

• • • • •

Follow-Up

Treatment

Diagnosis

2

Feline Panleukopenia Virus (FPV, Feline Parvovirus)

Notes

48

Hypothermia and shock DIC Mycotic infection Jaundice

SECTION TWO: PREVENTATIVE CARE

CBC (stage 3): anemia (v), lymphopenia, neutropenia Chemistry panel: ↑ protein and globulins Urinalysis: ↑ protein ELISA: + Western blot: confirms + results of ELISA Culture, plasma, saliva, tears, urine: FeLV isolated and identified

Antibiotics for secondary infection: metronidazole Appetite stimulants: cyproheptadine, diazepam Corticosteroids: prednisone Immune stimulants: interferon, zidovudine, ddC, PMEA, staphylococcal protein A, Propionibacterium acnes, acemannan

Isolate affected cats. Neuter males. Quarantine and test incoming cats. Retest high-risk cats regularly.

Transmitted through bite wounds, in utero, and transfusions Theoretically transmitted through intimate contact or fomites Shed in the saliva Most commonly seen in unneutered roaming males A kitten may test + when <6 months old due to maternal antibodies: retest at 8–12 months after all maternal antibodies are gone.

Table 2.14 / Feline Transmissible Diseases: Feline Leukemia Virus, Feline Rhinotracheitis Virus Feline Leukemia Virus (FeLV)

Feline Rhinotracheitis Virus (FHV-1, Feline Herpesvirus)

Definition

A retrovirus causing immunosuppression and various types of cancer, specifically lymphoma and leukemia. Cats may clear initial infection, but there is no cure for persistent infection, which ultimately leads to death.

One of the major causes of feline upper respiratory disease. A highly contagious viral disease causing rhinitis, conjunctivitis, and ulcerative keratitis.

Presenting Clinical Signs

• Persistent diarrhea and wasting

• Anorexia, cough (rare), depression, excessive lacrimation, hypersalivation, loss of voice, nasocular discharge, photophobia, sneezing

Examination Findings

• Conjunctivitis, fever, gingivitis, keratitis, lymphadenomegaly, periodontitis, rhinitis, skin infections, stomatitis

• Fever, conjunctivitis, herpetic ulcers, rhinitis, ulcerative keratitis

General

• History/clinical signs

• Clinical signs

Laboratory

• CBC: lymphopenia, neutropenia, nonregenerative anemia, thrombocytopenia, and immune-mediated hemolytic anemia • ELISA: virus antigen detection • Bone marrow aspirate or biopsy • IFA test: +

• CBC: transient leukopenia, leukocytosis • Virus isolation: cell cultures of swabs from the pharynx, nasal epithelium, or conjunctiva • IFA: viral detection • Stained conjunctival smears: intranuclear inclusion bodies detection

Imaging

• N/A

• Radiographs, skull: chronic disease shows changes in the nasal cavities and frontal sinuses

Procedures

• N/A

• N/A

General

• Symptomatic

• Supportive • Fluid therapy

Medication

• Antibiotics, esp. with Haemobartonella infection • Immunomodulatory drugs: interferon

• • • • •

Antibiotics: amoxicillin and enrofloxacin Antibiotics (ophthalmic) Antiviral eye medications: Vira-A Immunomodulatory drugs: interferon Lysine

Nursing Care

• Blood transfusions; many may be necessary. Using blood from FeLVvaccinated cats may reduce the level of FeLV antigenemia in some cats.

• • • •

Nutritional support, feeding tube placement Keep eyes and nose clear of discharge. Airway humidification ↑ Environmental temperature; herpesvirus is temperature sensitive

Treatment

Diagnosis

Presentation

Disease

CHAPTER 2 / PREVENTATIVE CARE AND VACCINATIONS

2

49

Table 2.14 / Feline Transmissible Diseases: Feline Leukemia Virus, Feline Rhinotracheitis Virus (Continued) Disease

Feline Leukemia Virus (FeLV)

Feline Rhinotracheitis Virus (FHV-1, Feline Herpesvirus)

Patient Care

• Symptomatic • Nutritional support, low stress environment, management of secondary conditions

• Confine indoors to decrease environmentally induced stress.

Prevention/Avoidance

• Vaccinate outdoor cats and those living with a FeLV-positive cat. • Quarantine and test all new cats to the household or local environment. • Prevent contact with FeLV-positive cats.

• Vaccinate. • Prevent contact with FHV-infected cats. • Virus shed intermittently

Complications

• • • • •

• • • •

Prognosis

• >50% of cats die from related diseases in 2–3 years

• Good; 7–10 days

• All FeLV-positive cats must remain indoors to prevent further spread of the disease. • Test each cat prior to first vaccine or if there has been a long period of time without vaccines. • More false-positive cats when using whole blood on the ELISA test • False negatives can be seen in cats infected within the last 1–3 months. • Do not use modified live vaccines. • Transmission is most commonly through cat-to-cat bites, grooming, shared dishes, litter boxes, in utero, or through nursing

• Transmission is through direct contact and fomites. • Very resistant virus; disinfect with 1:32 dilution of bleach water • Readily inactivated by commonly used disinfectants for months to years • Cats should be tested for FIV and FeLV to rule out underlying immunodeficiency syndromes.

Follow-Up

2

Notes

50

SECTION TWO: PREVENTATIVE CARE

Lymphoma Fibrosarcoma Glomerulonephritis Toxoplasmosis Haemobartonellosis

Chronic rhinosinusitis Persistent nasal discharge Herpetic ulcerative keratitis Permanent closure of nasolacrimal duct

Table 2.15 / Feline Vaccination Protocol

The site of vaccine injection varies between clinics, but it is important to have a designated location for each vaccine and to note these locations in each patient’s chart. Feline vaccines vary as to their route of administration: subcutaneously, intranasally/intraocularly, or transdermally. The Vet Jet transdermal vaccination system utilizes an internal spring system, which disperses the vaccine through the dermis into the dendritic cells.

2

Vaccine

≥16 Weeks of Age

>16 Weeks of Age

Injection Sitea

Vaccine Classificationb

FPV • Feline panleukopenia FCV • Feline calicivirus FHV-1 • Feline viral rhinotracheitis

• 1 dose at 6–9 weeks, then repeat every 3– 4 weeks until 16 weeks (e.g., 1 dose at 8, 12, 16 weeks) • 1 dose 12 months after initial, then 1 dose every 1–3 years dependent on manufacturer and hospital policy

• 2 doses, 3–4 weeks apart • 1 dose 12 months after initial, then 1 dose every 1–3 years dependent on manufacturer and hospital policy

• SQ on right lower shoulder • IN/conjunctival sacs, depending on manufacturer

Core

FeLV • Feline leukemia

• ELISA FeLV test for virus detection prior to vaccination • 1 dose at 8 weeks, then 1 dose 3–4 weeks later • Annually dependent on patient’s risk

• Elisa FeLV test for virus detection prior to vaccination • 2 doses; 3–4 weeks apart • Annually dependent on patient’s risk

• Transdermal on the left hind lower thigh area • SQ on the left lower thigh area

Noncore

Rabies • Rabies virus (RV)

• 1 dose at 8–12 weeks dependent on vaccine type • 1 dose every 1–3 years dependent on vaccine type and state requirements • Annually using canary-pox vector rabies vaccine

• 1 dose initially • 1 dose every 1–3 years dependent on vaccine type and state requirements • Annually using canary-pox vector rabies vaccine

• SQ on right hind lower thigh area

Core

FIV • Feline immunodeficiency virus

• 1 dose at 8 weeks, then 2 doses every 2–3 weeks • Annually dependent on patient’s risk

• 3 doses every 2–3 weeks • Annually dependent on patient’s risk

• SQ

Noncore

Core Core

a

Injection site, age of administration, and booster protocol may vary depending on the manufacturer of the vaccination. Recommendations by the individual manufacturer should be followed. The frequency may vary depending on the state’s requirements and the veterinarian’s protocol. Note: Possible reactions range from sensitivity at the injection site, a small bump or knot at the injection site, slight fever, hives, lethargy, to anaphylactic shock (vomiting, salivation, dyspnea, and incoordination) and injection site sarcomas. Any bump found at the injection site should be assessed by a veterinarian. b Core vaccines are those recommended to every dog. Noncore vaccines are recommended based on potential risk factors.

ANIMAL CARE Along with medical care provided by the veterinarian, owners must take an active role in the day-to-day health of their animals. Dental care, grooming, and basic medical procedures can help provide the animal with increased

health and longevity. Besides providing the basic care, it also allows the owners to be more aware of other health problems that might otherwise be missed (e.g., gum inflammation, tumors, pruritus, otitis externa).

CHAPTER 2 / PREVENTATIVE CARE AND VACCINATIONS

51

Skill Box 2.9 / Client Education: Home Dental Care 2

Home dental care should be a daily part of each animal’s life. The commitment to time, energy, and resources from the owner will impact the quantity and quality of their animal’s life.

• Brush the visible teeth (opposite side) and then repeat on the other side. Maintenance:

Supplies:

• Brush daily, at a minimum of 3 times a week.

• Toothbrush (e.g., fingerbrush, pet toothbrush, human toothbrush), gauze, washcloth, pantyhose

• Oral examination

• Veterinary toothpaste, beef bouillon, garlic or tuna water Age: • Home dental care should begin at 8–12 weeks of age. Brushing is not critical until the adult teeth erupt, but starting early allows the animal to become accustomed to the procedure during an impressionable period of development. Introduction: • Regardless of age, introduce brushing slowly and gradually, allowing the animal to determine the amount of time at each stage. • As each step is begun, observe for the animal’s reaction and only advance to the next step once the animal is comfortable. • Massage the animal’s muzzle and lips gently. • Introduce your finger dipped in beef bouillon or garlic water (canine) or tuna water (feline) into the buccal pouch under the upper lip and rub the gum line. • Introduce your finger covered with a gauze, washcloth, or pantyhose and rub the gum line and teeth in a circular motion. • Introduce a pet toothbrush or a very soft human toothbrush held at a 45° angle to the tooth surface, brushing in a oval motion. • Introduce the toothbrush with veterinary toothpaste. • As the animal accepts the procedure, brushing of the lingual surfaces can begin. • Place the nonbrushing hand over the muzzle and tilt head backward to open the animal’s mouth.

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SECTION TWO: PREVENTATIVE CARE

• Gums: redness, swelling, bleeding, pus • Teeth: loss, instability, broken, change in color • Mouth: halitosis, growth Adjuncts to brushing: • Dental diets or treats • Rawhide bones (e.g., Nylabone) • Yearly dental examinations and cleanings, if needed Tips for successful brushing: • Select the same time each day to brush so the animal expects it (routine and repetition). • Brushing in the evening is often preferred as everyone is in a more quiet mood. • Sessions should be short, roughly 2–3 minutes. • Offer praise and reassurance during and following the brushing. Avoid: • Human toothpaste, baking soda, or hydrogen peroxide • Heavy restraint • Brushing aggressively • Brushing if the procedure may cause pain (e.g., recent thorough oral examination, existing CLL, exposed pulp cavities, gingivitis, ulcerations, tooth mobility) • Natural bones, cow hooves, hard nylon toys as they may fracture teeth

Skill Box 2.10 / Grooming

Skill Box 2.11 / Bathing

Grooming is a segment of veterinary care that is limited and typically presents itself as client education. Even though staff may not routinely provide grooming services, clients often have questions regarding the general care of their pets. Brushing, bathing, and toenail trims are the most basic of grooming procedures. There are also certain procedures that may be performed during periods of medical conditions that must be continued routinely to avoid reoccurrence of the problem, such as anal gland expression and ear cleaning and flushing. Brushing should be a routine part of pet care to remove dead fur and dirt and to prevent matting. Besides providing the animal with a shinier and healthier coat and a chance to look and feel for abnormalities, it also allows bonding between the animal and the owner. There are many types of brushes and combs available for specific types of coats; a variety of options can be helpful. Applying a detangler spray before beginning may help with tangled or slightly matted fur. Using a systematic approach, begin at the head and work toward the tail. Use a gentle stroke, as ripping or pulling at the fur is painful and will make brushing a negative experience. For animals with long, thick coats, brush the fur against the natural lay of the fur and then finish with brushing fur down. Following up with a comb may help remove the extra loose fur.

1. Location: a safe place for both owner and animal to stand, a mixture of hot and cold water available, and an area able to withstand water (e.g., shaking wet dog) • Place a towel or mat in the bottom of the tub to supply traction for the animal. • Have a leash hook fastened to the wall so the animal can be secured without having to always have a hand on the animal. 2. Supplies: multiple towels, appropriate shampoo, plastic apron, gloves (depending on type of shampoo) and protective eyewear. 3. Comb, brush, and demat to remove excess fur, which allows better penetration of shampoo as detailed above. 4. Wet down the animal completely, making sure to get water down to the skin. 5. Apply the shampoo and lather the entire animal, including face. 6. Leave shampoo on for the amount of time indicated on the bottle or by the veterinarian. • Use a timer to ensure that the shampoo is on for the correct time: do not guess. 7. Rinse the animal completely, making sure to remove all soapy residue. 8. Dry the animal’s haircoat and ear canals with a combination of shaking (removes 95% of the water) and towels. • Blow in the animal’s ear to get them to shake. • Dry the ear canals, using either cotton balls or a vinegar rinse. Note: Keep the animal in a warm place until completely dry to avoid the animal becoming chilled. 9. Comb and brush out the animal after the bath to remove all the hair that was loosened. Note: Do not use lubricants in the eyes; it may trap the shampoo in the eye instead of protecting the eye. • Do not place an animal in a heater/dryer cage without direct supervision and access to water to prevent overheating and death of the animal. • If drying an animal with a blow dryer, be sure to keep the dryer on the lowest setting and continuously moving to prevent burns to the animals. CHAPTER 2 / PREVENTATIVE CARE AND VACCINATIONS

53

2

2

Skill Box 2.12 / Nail Trimming

Skill Box 2.13 / Anal Sac Expression

Nail trimming is another routine part of pet care. Failing to trim the nails may lead to the nails growing into the pad of the paw, difficulty or inability of the pet to walk, and pain and pad injuries. Most animals are adverse to nail trimming and may need some coaxing. Choosing a time when the pet is tired and comfortable may make the experience more tolerable. When trimming, it is best to hold the trimmer perpendicular (cutting top to bottom) to the nail; when held parallel (cutting side to side), crushing and splintering of the nail may take place. When trimming nails, it is important to avoid cutting the quick, which consists of the blood vessels and nerves that supply the toenail. In dogs, light-colored nails are easy to trim as the blood supply is easily seen and avoided. Dark-colored nails can be difficult to trim and should be done in small cuts. As small cuts are made, the white to pink crescent shape will begin to appear in the middle of the nail. This represents the quick, and continuing to cut will eventually lead to bleeding. Remember to cut all nails including the dewclaws on both front and rear feet. The rear feet nails are typically shorter and require less trimming. In cats, the paw is gently squeezed to expose the nails and then they are trimmed to within 2 mm of the quick.

1. Supplies: gloves, lubricant (e.g., K-Y Jelly), alcohol, absorbent material (e.g., rolled cotton, paper towels, baby wipes), and deodorizer

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SECTION TWO: PREVENTATIVE CARE

2. Put alcohol-soaked absorbent material into the gloved hand during the expression to catch the expressed material, insert the forefinger into the rectum, and immobilize the sac between the forefinger and the thumb on the outside of the rectum. 3. Gently apply pressure to the sac with thumb and forefinger (located at the 4 and 8 o’clock positions when looking at the anus), milking from the bottom of the sac upward toward the duct opening. 4. Note the amount and character of the material expressed. Normal secretions are a clear to slightly greenish, foul-smelling (similar to dead fish) substance that is a liquid to a paste in consistency. Material that is very thick or purulent or very dark should be brought to the attention of the veterinarian. 5. Clean the perianal area of the animal with alcohol-soaked material or baby wipe and then spray with a deodorizer. • If using powdered gloves, put 2 gloves on the hand doing the expression, then remove 1 glove after each sac is expressed. • If having difficulty expressing a gland, try rolling the skin outward with the finger outside the rectum to better expose the duct. • If having trouble with positioning, switch and use the thumb on the inside and the forefinger on the outside or teach yourself to be ambidextrous and express the right gland with the left hand and vice versa.

Skill Box 2.14 / Ear Cleaning and Flushing Method

Ear Cleaning

Ear Flushing

Equipment

• Cotton ball • Cleaning solution (chlorhexidine, povidone iodine, Oti-clens, Epi-Otic) • Bulb syringe/syringe without the needle • towel

• • • • • •

Cotton ball Cleaning solution (Ceremune) Ear irrigator (filled with warm water) Video scope or endoscope Anesthetized patient 5 Fr red rubber feeding tube (cut to about ½ its length)

Technique

• Verify the patient has an intact tympanic membrane. • Using either a bulb syringe or syringe without the needle, fill the ear canal with cleaning solution. Be careful not to form a seal between the instrument and the ear canal, and do not use a direct stream on the tympanic membrane. • Put a towel or piece of roll cotton at the entrance of the ear canal and begin gently massaging the ear canal from the bottom up. This will work the solution from the bottom of the ear canal to the opening. With a cotton ball, gently wipe out any debris. Do not push cotton ball in the ear any farther than your finger will go easily. • Repeat steps 1 and 2 until the ear canal and solution on the cotton ball come out clean (5–10 times). • To dry the ear canal, use either a flushing solution or suction via an infant feeding tube attached to a syringe.

• • • • •

Take a picture of the ear canal. If cytology has not been done, take a sample of the ear debris. Insert the Ceremune or other ear cleaner, and massage gently for 3–4 minutes. Wipe out any excess at the entry of the ear. Insert the feeding tube onto the ear irrigator nozzle and turn on the machine, verifying that the pressure gauges are registering as prescribed in the manual. Position the video scope or endoscope into the ear, and then insert the feeding tube into the port and watch on the monitor screen to see the tip protrude from the scope. Depress the water button on the trumpet, release, and then depress the suction button and suction out debris and liquid. Repeat several times. Remove the feeding tube if debris is clogging the tip and clean. A reapplication of the ear cleaning solution may be necessary in ears with a lot of debris. Be sure to remove all of the Ceremune. Take a second picture of the clean canal. Insert any medications if needed.

• • • • • •

2

Note: See Figure 1.19, Ear, page 13.

CHAPTER 2 / PREVENTATIVE CARE AND VACCINATIONS

55

Chapter

3

3

Nutrition General Nutrition 58 Daily Caloric Requirement Worksheet for a Healthy Animal 59 General Life Stage Feeding Guidelines

Body Condition Scoring System 62 Disease Nutritional Requirements 64 Obesity Management 68 60

Key Words and Termsa Aerophagia Alkali Amino acid Antigenic Bioactive amines Bioavailability Cachexia Carbohydrate Daily energy requirement Digestibility Energy Fat Fatty acid Fiber Hydrolyzed protein Kilocalorie a

Life stage Malnutrition Meat byproducts Meat meal Metabolism Micronutrient Mineral Neonate Nitrogenous waste Nutrient Obesity Protein Resting energy requirement Vasoactive amines Vitamin

Abbreviations

Additional References, page

AAFCO, Association of American Feed Control Officials BCS, body condition score BW, body weight CHF, chronic heart failure DER, daily energy requirement EPI, exocrine pancreatic insufficiency FLUTD, feline lower urinary tract disease GIT, gastrointestinal tract kcal, kilocalorie ME, metabolizable energy NPO, nothing by mouth PLE, protein losing enteropathy RBC, red blood cell RER, resting energy requirement

Laboratory, 71 Parenteral nutrition, 422 Pharmacology, 567 Physical examination, 18 Urinalysis, 147

Key words and terms are defined in the glossary on page 631.

57

GENERAL NUTRITION

3

Proper nutrition is as important as physical examinations, vaccinations, and dental care in maintaining a healthy pet. Unfortunately, not much time is usually given to the subject during client education. Obesity remains the biggest nutritional challenge; it is estimated that 24–44% of dogs and cats in the United States are overweight. Understanding how to feed a pet according to its life stage, how to determine their current condition, how to alter their nutrition based on disease changes, and how to get a pet back to its ideal condition are the keys to proper clinical nutrition. The most important component of proper nutrition begins with a high-quality diet formulated to the appropriate life stage of the animal. Poor-quality, unbalanced, commercial diets; homemade diets of single-food items; indiscriminate mixtures of singlefood items; and variable supplements will lead to dietary imbalances. Along with proper nutrition, fresh, clean water must be provided at all times. Owners often look to the veterinary staff for a better understanding of the “right” diet to feed their pet. Many would like a concrete comparison

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SECTION TWO: PREVENTATIVE CARE

between different foods, but unfortunately this is virtually impossible to do. The information provided in the ingredient list and on the information panel appears at first glance to be consistent between products, but the variables that exist render a comparison unattainable. The most reliable way to evaluate a food is to evaluate the health and appearance of the animal that is eating it. Each animal is an individual and will handle each diet differently. Some basic guidelines to providing a quality diet include feeding diets that have passed the Association of American Feed Control Officials (AAFCO) feeding trials, feeding diets appropriate for the animal’s life stage, and feeding diets containing meat (not including meat byproducts and meat meal). Some indications that a diet change may be indicated for a particular pet are poor body condition, flatulence, borborygmus, ↑ fecal volume and frequency, changes in the expected appearance of the haircoat. Home-prepared diets can be a very valuable option when an approved recipe is followed to guarantee the proper nutrients have been included. Only those recipes formulated by a credentialed veterinary nutritionist should be considered and then not altered.

Skill Box 3.1 / Daily Caloric Requirement Worksheet for a Healthy Animal Many factors affect the energy requirements of animals. Understanding these factors may prevent an animal from becoming obese. Daily caloric requirements are altered by the physiologic state (e.g., adult maintenance, pregnancy, lactation, and growth), activity level, temperament, environmental temperature, and the diet’s digestibility. The calculations below provide a starting point; adjustments will need to be made based on each individual animal. Step 1: Calculate Daily Resting Energy Requirement (RER) RER = 70 × (current body weight in kg)0.75 or, for animals weighing between 2 and 30 kg: RER = (30 × current body weight in kg) + 70 = ______ kcal/day Adjust kcal based on visual and manual examination and the BCS of animal. Tip: To calculate (BW kg)0.75 without a scientific calculator: multiply the weight by itself 3 times, then take the square root twice Step 2: Calculate daily energy requirement (DER) by multiplying the RER by the activity factor. Life Stage

Activity Factor (RER × ______ = DER) Canine

Feline

2.0

1.6–2.0

Gestation Weeks 5–9 Lactation Week 1–2

1.5a

Week 3–5

a

2.0

1.5 1.5–5.0

Growth Weaning to 50% of adult BW

3.0

3.0

51% of adult BW to adult

2.0

2.0

Inactive, neutered

1.6

1.2

Inactive, intact

1.8

1.4

Active/working

2.0–6.0

1.6

Adult

a 25% of the RER should be provided for each pup in addition to the dam’s DER. These calculations do not take into consideration the type of breed and their differences in growth requirements. Adjust kcal based on visual and manual examination of animal.

Step 3: Calculate volume of food required ______ kcal/day/ ______ kcal/cup or can of food = ______ cup/can(s) of food/day Step 4: Calculate amount of each feeding ______ cup/can(s) of food/day/2–3 feedings per day = ______ cup/can(s) of food/feeding

CHAPTER 3 / NUTRITION

59

3

Table 3.1 / General Life Stage Feeding Guidelines

Each stage of an animal’s life presents changes in nutritional needs. The overall goal of nutrition is to obtain an optimum body condition score (see Table 3.2 Body Condition Scoring System, page 61) while providing the correct balance of nutrients, vitamins, and minerals. Age

Diet

Feeding Method

Comments

Birth to Weaning

• Dam/queen’s milk • Commercial replacement diets • Home prepared replacement diets • See Skill Box 2.1 Care and Feeding of Orphaned Puppies and Kittens, page 27. • Energy requirement is 22–26 kcal/100 g • Begin introducing puppy or kitten diet at 3–4 weeks of age as milk will no longer provide adequate calories or nutrients • Weaning begins at 6–8 weeks of age

• Nursing neonates will feed ad lib • See Skill Box 2.1 Care and Feeding of Orphaned Puppies and Kittens, page 27. • Starting solid food • Mix growth food with warm water to moisten and make into a slurry; place food in a shallow dish. • Allow free access 3–4 times a day. • Remove after 20–30 minutes to prevent bacterial overgrowth. • Neonates can be encouraged to eat by placing their feet in the food, smearing food on their lips, or introducing food into their mouths. • Weaning • Complete weaning should not start before 6 weeks of age (preferably 7–8 weeks of age) and not until close human contact has occurred, and typically does not need assistance after solid foods have been started. • The dam/queen should be separated from the neonates the day before weaning. The neonates should be fed, and food should be withheld from the dam/queen. Water is not removed. • The neonates should be reunited with the dam/queen overnight and be allowed to nurse to drain the mammary glands. Food only should be withheld from both the dam/queen and the neonates overnight. • The neonates are removed from the dam/queen the next day

• Body fat stores are only 1–2% at birth, presenting the risk of hypoglycemia, starvation, and hypothermia. • Adequate glycogen reserves do not develop until after first few days of nursing. • All neonates need to receive colostrum in the first 24 hours of life to ensure transfer of passive immunity. • Hypothermia can lead to poor nursing.

Weaning to 12 Months

• Puppy • Highly digestible, high-quality protein • 25–29% protein of ME • Large- and giant-breed dogs • Overfeeding and extra micronutrients (e.g., calcium) during rapid growth phase contribute to obesity and developmental orthopedic disease. • Maintain feeding puppy diet until an adult to avoid ↑ calcium consumption. • Adjust food intake to maintain a BCS of 2/5. • Kitten • 30% protein of ME • Maintain feeding kitten diet until maturity (10–12 months) if obesity is present, then ↓ amount of food fed.

• Puppy • 2–4 measured feedings per day • Large- and giant-breed dogs • Measured feedings 3–4 meals daily • Remaining food after a meal should be discarded and subsequent meals should be reduced in quantity. • Kitten • Free-feed or measured feedings 2–3 times a day • Neutering ↓ energy requirements by 24–33%

• Obesity: developmental orthopedic disease (large breed) • Thin: hypoglycemia (small breed)

Puppy and Kittens

3

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SECTION TWO: PREVENTATIVE CARE

Adult

Table 3.1 / General Life Stage Feeding Guidelines (Continued) Age

Diet

Feeding Method

Comments

Maintenance

• High-quality adult food • Homemade diets made from approved published recipes

• 2–3 measured feedings per day • See Skill Box 3.1 Daily Caloric requirement Worksheet, page 58.

• Obesity: diabetes, osteoarthritis, skin problems, surgical risk • Thin: hypoglycemia, hypothermia, muscle disorders

3

Pregnancy Canine

• Diet should gradually be changed during the last 3 weeks to a puppy growth diet to provide additional nutrients. • Avoid • Carbohydrate-free meat-type diets should be avoided during gestation and whelping to prevent hypoglycemia and ↑ neonate death.

• During the first 5 weeks, the feeding schedule should not change, and the dam should maintain her normal weight. • Weeks 6–9 • Frequency • Feed smaller, more frequent meals to accommodate the shrinking stomach size • Amount • ↑ 15% each week • By gestation, the dam’s weight should ↑ 15–25%.

• Obesity: ↓ ovulation, ↓ litter size, large neonates, dystocia • Thin: trouble conceiving, ↓ birth weights, ↑ neonate death

Feline

• High-quality diet intended for reproduction/lactation or growth

• Weeks 2–9 • Amount • ↑ Gradually to a total ↑ of 25–50% • By gestation, the queen’s weight should ↑ by about 40%.

• Obesity: large neonates, dystocia • Thin: trouble conceiving, abortion, ↓ birth weights, ↑ neonate death

Lactation Canine

• High-quality puppy growth food • Avoid • Low-calorie diets (e.g., weight-reducing diets)

• Feed free-choice • Daily energy requirements are approximately 3 times that of nonlactating adults. • Lactation peaks at 3–5 weeks postpartum and is maintained until 8 weeks postpartum. • The dam requires approximately 25% of her DER additional for each neonate.

• Obesity/thin: insufficient milk production

Feline

• High-quality diet intended for reproduction/lactation or growth

• Lactation peaks at 3–4 weeks postpartum • The queen requires 2–3 times her DER during lactation. See Skill Box 3.1 Daily Caloric Requirement Worksheet, page 58.

• Obesity/thin: insufficient milk production

Geriatric

• High-quality adult food for healthy animals • Homemade diets made from approved published recipes • Changes in diet (e.g., protein, fat, phosphorous, sodium, fiber, vitamins, minerals) can be made based upon medical conditions.

• 2–3 measured feedings per day • See Skill Box 3.1 Daily Caloric Requirement Worksheet, page 58, on calculating the appropriate amount of food. • The caloric intake may need to be reduced to obtain the desired BCS. • Avoid placing feeding dishes in hard-to-reach places.

• Obesity: diabetes, osteoarthritis, skin problems, surgical risk • Thin: hypoglycemia, hypothermia, muscle disorders

CHAPTER 3 / NUTRITION

61

Table 3.2 / Body Condition Scoring System

The Body Condition Scoring System standardizes the interpretation of the overall physical appearance of the animal. It should be a basic part of every examination and should be noted in the record for future comparison. This technique can be easily and quickly taught to clients as part of weight management at home. The BCS can change by 1 value with a 10% change in body weight. 3

Canine

Body Condition Score 1: Very Thin Ribs: easily visible and felt with no cover Waist: severe waist Tail Base: lumbar vertebrae and pelvic bones are raised with no fat between the skin and bone Side View: severe abdominal tuck Overhead View: accentuated hourglass shape

2: Underweight Ribs: easily felt with minimal fat cover Waist: easily noted Tail Base: bones are raised with minimal fat between the skin and bone Side View: prominent abdominal tuck Overhead View: marked hourglass shape

3: Ideal Ribs: easily felt with slight fat cover Waist: observed behind ribs Tail Base: smooth contour but bones can be felt under a thin layer of fat Side View: abdominal tuck Overhead View: well-proportioned waist

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SECTION TWO: PREVENTATIVE CARE

Feline

Table 3.2 / Body Condition Scoring System (Continued) Canine

Body Condition Score

Feline

4: Overweight Ribs: difficult to feel with moderate fat cover Waist: poorly discernible Tail Base: some thickening but bones can be felt under a moderate layer of fat Side View: no abdominal tuck Overhead View: back is slightly broadened

3

5: Obese Ribs: difficult to feel under thick fat cover Waist: absent Tail Base: thickened and difficult to feel bones beneath prominent layer of fat Side View: fat hangs from the abdomen Overhead View: markedly broadened and prominent paralumbar fat deposits

CHAPTER 3 / NUTRITION

63

Table 3.3 / Disease Nutritional Requirements

3

Each disease or combination of diseases alters the nutritional requirements of a patient. Each patient should have a complete nutritional evaluation to ensure the type of diet and the feeding method are appropriate. The overall consideration regarding nutrition is to optimize BCS. Often it is more important to maintain a patient eating versus providing the exact nutritional requirements. For example, it is more important for a patient with CHF to consume enough food to prevent cachexia than it is to restrict sodium. It often requires a dedicated owner to cater to the changing desires of the patient along with providing the necessary nutritional requirements. It is beyond the scope of this book to provide specific alterations; please consult dedicated nutritional references and seek the advice of a credentialed veterinary nutritionist for specific nutritional alterations. Disease

Objective

Comments

Anemia

• Support RBC production.

• Nutritional evaluation: minerals (e.g., iron), protein, vitamins (e.g., B) • Iron deficiency is usually due to excessive loss (e.g., hemorrhage, GIT ulcers, and ectoparasitism) versus inadequate intake.

Bone Loss and Fracture Repair

• Ensure diet is properly balanced. • Ensure adequate energy and protein intake.

• Nutritional evaluation: energy, minerals (e.g., calcium, phosphorus), protein • Supplemental calcium must be absorbable and balanced with phosphorous intake.

Cardiac Disease

• • • •

Control or correct cachexia. Maintain BCS. Control sodium retention. Encourage eating.

• Nutritional evaluation: amino acids (e.g., taurine), carnitine, energy, minerals (e.g., chloride, magnesium, phosphorus, potassium, sodium), water • Sodium and chloride restriction is based on the degree of cardiac disease • Additional sources of sodium should be considered (e.g., softened water, treats, table scraps) when determining total sodium intake.

Constipation

• • • •

Normalize GIT motility. ↑ Water consumption ↑ Bulk or ↓ quantity Optimize BCS.

• • • • • • • •

Nutritional evaluation: fiber, water Feed a highly digestible diet. ↑ Fiber ≤5% per week until clinical signs resolve Additional fiber may be achieved through therapeutic veterinary diets or adding ≤10% fiber to regular diet (e.g., pumpkin, high-fiber cereal). Provide small, frequent meals. ↑ Exercise and prevent obesity. Encourage defecation (e.g., frequent walks, clean litter box). Check anus/rectum for causes of poor defecation habits, tenesmus, or dyschezia.

Degenerative Joint Disease

• ↓ Degenerative joint changes • Optimize BCS.

• Nutritional evaluation: fatty acids, vitamins (e.g., E) • ± Chondroprotectives

Dental Disease

• Prevent or correct periodontal disease. • Optimize oral health.

• Nutritional evaluation: carbohydrates, minerals (e.g., calcium, phosphorus), protein, vitamins (e.g., A, B, C, D), water • Food texture and composition may contribute to ↓ plaque accumulation.

Diabetes Mellitus

• Optimize BCS. • Minimize postprandial fluctuations in blood glucose. • Consistent feeding times and caloric intake

• Nutritional evaluation: energy, fat, fatty acids, fiber, minerals, protein, soluble carbohydrates, water • Avoid semimoist foods as they contain simple carbohydrates and may have a hyperglycemic effect. • Provide small, frequent meals and weigh animal frequently. • Changes in exercise and weight may necessitate altering the insulin dose.

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SECTION TWO: PREVENTATIVE CARE

Table 3.3 / Disease Nutritional Requirements (Continued) Disease

Objective

Comments

Exocrine Pancreatic Insufficiency (EPI)

• Correct malnutrition. • Reduce requirements for digestive enzymes. • ↑ Caloric intake/density • Optimize BCS.

• Nutritional evaluation: fat, fiber, vitamins (e.g., A, D, K, cobalamin, folate) • Avoid high-fiber diets. • Provide small, frequent meals.

Flatulence

• ↓ Intestinal gas production and bacterial fermentation of undigested food • ↓ Aerophagia

• • • •

Food Allergy

• Identification and avoidance of offending foods (protein) and/or food additives • Relieve clinical signs (e.g., otitis, pruritus, dermatitis, erythema, peripheral lymphadenopathy).

• Nutritional evaluation: food additives, protein, vasoactive or biogenic amines • An elimination diet is feed exclusively for 8–12 weeks consisting of 1–2 protein sources the patient has not be exposed to and void of food additives, vasoactive and biogenic amines, and excess protein. • Regardless of diet fed (e.g., commercial or home prepared), it must be nutritionally adequate for the patient’s life stage and condition. • Diet should be continued 2–3 weeks past glucocorticoid administration. • Canned food contains the least amount of additives. • Feeding dishes should be glass, ceramic, or stainless steel. • Outdoor pets should be confined to avoid dietary indiscretions. • Avoid all flavored medications, treats, table scraps, and vitamin supplements. • With the disappearance of clinical signs, begin feeding 1 eliminated food item back daily for 7 days, discontinue if relapse is noted or assume no allergy if no reactions are seen after 7 days.

Hepatic Disease

• Maintain body weight and BCS. • Promote hepatic regeneration. • ↑ Caloric intake/density

• Nutritional evaluation: amino acids (e.g., taurine), energy, fat, fiber, minerals (e.g., iron, potassium, zinc), protein, vitamins (e.g., C, E, K) • Feed a highly digestible diet. • Provide small, frequent meals while slowly ↑ amount fed over a few days.

Hepatic Lipidosis

• Correct anorexia and malnutrition. • ↑ Caloric intake/density

• Nutritional evaluation: carnitine, energy, fat, minerals (e.g., iron, potassium, zinc), protein, vitamins (e.g., C, E, K) • Recovery is directly related to early diagnosis and treatment via enteral or parenteral nutrition.

Hyperadrenocorticism

• Prevent or correct cachexia. • Optimize BCS.

• Nutritional evaluation: fat, fiber, minerals (e.g., chloride, sodium), protein, water • Feed a highly digestible diet.

Hyperthyroidism

• Correct cachexia. • Optimize BCS.

• Nutritional evaluation: energy, fat, minerals (e.g., calcium, chloride, iodine, iron, phosphorus, potassium, selenium, sodium), protein, water • Feed a highly digestible diet. • Poor absorption of many nutrients and ↑ metabolism

Hypoadrenocorticism

• Optimize BCS.

• Nutritional factors to evaluate: energy, minerals (e.g., chloride, potassium, sodium), protein, water • Feed a highly digestible diet.

3 Nutritional evaluation: carbohydrate, fiber, protein, variable per patient Feed a highly digestible diet. Provide small, frequent meals. Discourage gluttony; provide a noncompetitive environment or slow consumption via novel methods. • ↑ Exercise and ↓ stress

CHAPTER 3 / NUTRITION

65

Table 3.3 / Disease Nutritional Requirements (Continued) Disease

Objective

Comments

Hypothyroidism

• Optimize BCS.

• Nutritional evaluation: fat, energy, fiber, trace minerals

Inflammatory Bowel Disease

• ↓ Antigenic stimulation of the GIT • Provide GIT rest and normalize motility. • ↑ Water consumption

• Nutritional evaluation: energy, fat, fatty acids, fiber, minerals (e.g., potassium, zinc), protein, vitamins (e.g., thiamin, vitamin K) • Diets may consist of a highly digestible low-residue GIT diet, ↑ fiber, or an elimination diet (a “sacrificial” novel protein is fed initially while the GIT is healing and then replaced by a second novel protein or hydrolyzed protein diet long term).

Obesity

• ↓ Body weight and optimize BCS • Control caloric intake. • Prevent obesity-related diseases.

• Nutritional evaluation: carbohydrates, energy, fat, fiber, protein • Prevention is easier than treatment of obesity. • See Skill Box 3.2 Obesity Management, page 67.

Oncology

• Prevent or correct cancer cachexia. • ↑ Nutrient intake • Encourage eating.

• Nutritional evaluation: amino acids (e.g., arginine, glutamine, glycine, tyrosine, phenylalanine, methionine, asparagine), fat, fatty acids, carbohydrates, protein, vitamins (e.g., retinoids, vitamins C and E, beta-carotene) • Feed a highly digestible diet. • Nutritional intervention must begin early in disease to prevent cachexia.

Orthopedic Disease, Developmental

• ↓ Nutrition-related disease • Optimize BCS.

• Nutritional evaluation: energy, fat, minerals (e.g., calcium, copper, phosphorus, zinc), vitamins (e.g., A, C, D) • Overfeeding and extra vitamins (e.g., calcium) during rapid growth phase in large- and giant-breed dogs lead to skeletal disease. • Switching growing animals to an adult food should be avoided as nutritional factors may be inappropriately altered (e.g., calcium). • See Table 3.1 General Life Stage Feeding Guidelines, page 58.

Pancreatitis

• ↓ Pancreatic secretions • Provide pancreatic rest. • Optimize BCS.

• • • • •

Nutritional evaluation: fat, protein, water Feed a highly digestible diet. Enteral and/or parenteral feeding may be part of the initial treatment. Traditional low-fat, weight-reducing diets may be too calorie restrictive. Canine: NPO for 3–7 days, begin with small amounts of water, gradually add in a carbohydrate (e.g., rice) and then a protein source of ↑ bioavailability (e.g., cottage cheese, lean meat)

Protein Losing Enteropathy (PLE)

• Correct cachexia. • ↓ Enteric loss of plasma protein

• • • • •

Nutritional evaluation: carbohydrates, fat, fiber, protein Feed a highly digestible diet. Determining the underlying cause of PLE may alter nutrition. Monitor for protein malnutrition. Provide small, frequent meals.

Renal Disease

• Delay progression of renal failure. • ↓ Amount of nitrogenous waste (↓ azotemia) • Prevent malnutrition and optimize BCS. • ↑ Water consumption • Encourage eating.

• Nutritional evaluation: acid load, amino acids (e.g., arginine), energy, fat, fiber, minerals (e.g., chloride, phosphorus, potassium, sodium, protein, vitamins (e.g., A, B, D), water • Feed a highly digestible diet. • Avoid excess dietary protein in moderate to severe renal failure. • Protein recommendations: • Dogs: 2.0–2.2 g/kg/day • Cats: 3.3–3.5 g/kg/day • Monitor and control mineral imbalances (e.g., phosphorus, calcium). • Optimizing BCS is more important than restricting protein. • Sodium restriction should take place gradually over 2–4 weeks.

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SECTION TWO: PREVENTATIVE CARE

Table 3.3 / Disease Nutritional Requirements (Continued) Disease

Objective

Comments

Urolithiasis, Canine– Ammonium Urate

• Maintain alkaline urine (pH of 7.0–7.5). • Dissolution and prevention of uroliths • ↑ Water consumption and subsequent ↓ urine concentration

• Nutritional evaluation: protein, water • Dissolution on average take 4 weeks. • Meat-based diets tend to have ↑ purine; vegetable-based diets may be more suitable.

Calcium Oxalate

• Maintain alkaline urine (pH of 7.1–7.7). • Prevent uroliths. • ↑ Water consumption and subsequent ↓ urine concentration

• Nutritional evaluation: minerals (e.g., calcium, magnesium, sodium), oxalates, protein, vitamins (e.g., B6, C, D), water • Medical regimen dissolution is not possible for calcium oxalate stones, once formed.

Cystine

• Maintain alkaline urine (pH of 7.5). • Dissolution and prevention of uroliths • ↑ Water consumption and subsequent ↓ urine concentration

• Nutritional evaluation: protein, water • Dissolution can be possible with the addition of 2-MPG.

Struvite

• Maintain acidic urine (pH of 6.2–6.4). • Resolve underlying infection. • ↑ Water consumption and subsequent ↓ urine concentration

• Nutritional evaluation: minerals (e.g., magnesium, phosphorus), protein, water • Dissolution on average takes 3.5 months. • Avoid long-term feeding of dissolution diet due to ↓ protein and sodium.

• Maintain alkaline urine (pH of 6.6–6.8). • Prevent uroliths. • ↑ Water consumption and subsequent ↓ urine concentration

• Nutritional evaluation: fat, fiber, minerals (e.g., calcium, magnesium, sodium), oxalates, protein, vitamins (e.g., B6, C, D), water • Medical regimen dissolution is not possible for calcium oxalate stones, once formed.

• Maintain acidic urine (pH of <6.4) • Dissolution and prevention of uroliths • ↑ Water consumption and subsequent ↓ urine concentration

• Nutritional evaluation: fat, minerals (e.g., magnesium, phosphorus, potassium), protein, water • Average dissolution is 35 days after negative radiographs • Avoid feeding dissolution diet to immature, pregnant/lactating, renal failure, CHF, metabolic acidosis, hypertensive or hypokalemic patients • Free choice feeding provides a more desirable stable urinary pH, but may contribute to obesity

• Provide GIT rest to ↑ gastric secretions and normalize motility. • ↑ Water consumption • ↑ Bulk • ↑ Caloric intake/density

• Nutritional evaluation: amino acids (e.g., glutamine), energy, fat, fiber, minerals (e.g., chloride, potassium, sodium), water • NPO for 24–48 hours, offer small amounts of water every 2–3 hours, then begin small amounts of food 6–8 times a day • Gradually reintroduce normal diet after diarrhea is resolved (2–3 normal stools in a row). • Small, frequent meals to prevent gluttony

Urolithiasis, Feline Calcium Oxalate

Struvite

Vomiting/Diarrhea

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CHAPTER 3 / NUTRITION

67

Skill Box 3.2 / Obesity Management

3

As the rate of obesity among companion animals continues to rise, clients are in the need of obesity management education. Obesity alone can lead to or further contribute to numerous health concerns, such as diabetes, FLUTD, hepatic lipidosis, orthopedic diseases, and skin diseases. Although prevention early on is the key, a weight loss program can be successfully implemented and carried out with appropriate owner compliance. Becoming overweight is as simple as consuming more energy than the body is able to utilize. There are some medical conditions that can contribute to obesity (e.g., hypothyroidism), but the majority of animals are simply eating too much relative to their exercise/activity level. Therefore, decreasing the amount of food consumed or increasing the amount of exercise will lead to weight loss. Obesity management should be implemented when an animal is classified as having a body conditioning score of 4/5 or 5/5. See Table 3.2 Body Condition Scoring System, page 61. The following steps along with owner compliance should provide a happier and healthier pet. Additional information for the owner should include monitoring the amount of treats, the feeding habits of other family members, and the foods of other household pets. • A full examination of the patient along with appropriate diagnostic testing submitted to rule out medical issues (e.g., blood work, urinalysis) • Obtain a complete dietary history including the names and amounts of food fed (e.g., commercial diets, home prepared diets, treats, table scraps), access to additional food sources (e.g., other pet’s food, other family members or neighbors feeding the pet, hunting) • Calculate the current caloric intake and restrict to 60–80% of this amount. If it is not possible to obtain an accurate diet history, calculate the DER for the optimal weight of the patient. See Skill Box 3.1 Daily Caloric Requirement Worksheet, page 58.

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• Verify the protein content of the food at the recommended calories is adequate for that particular animal (1 g protein/lb body weight/day). Failure to verify protein content may lead to muscle loss along with fat loss. • Set smaller, more reasonable weight loss goals over a specified amount of time. The use of the BCS can help the owner better understand the goal. • Weigh the animal every 2–3 weeks to ensure a weight loss and verify all recommendations are being followed. The goal of weight loss is 1–2% per week; if this number is not obtained, further restrictions in calories should be done. Weight loss >2% a week is thought to be detrimental to the patient’s health. • Treats should be <10% of the total daily calories and must be calculated into the total daily calories. • Start or increase the daily exercise program to ↑ calorie expenditure, ↑ muscle mass, and stimulate metabolism. • The addition of microsomal triglyceride transfer protein inhibitors (e.g., Slentrol) may prove beneficial, as well as modifying feeding amounts and habits. Tips for success: • Feed multiple small meals a day to satisfy the pet. • Provide appropriate snacks (e.g., low- calorie commercial treats, plain popcorn, plain rice cakes). • Enlist all family members to be active participants in the weight loss program. • Keeping pets out of the kitchen during preparation and consumption reduces begging and owner’s impulse to feed.

Section

Three

Diagnostic Skills Chapter 4: Laboratory 71 Chapter 5: Imaging 157 Color Plate Chapter 6: General Medicine 201 Chapter 7: Emergency Medicine 299

Chapter

4

4

Laboratory Blood Chemistries 74 Blood Collection, Handling, Storage, and Transport Tips 74 Blood Collection Tubes 75 Blood Chemistries 76 Bone Marrow Evaluation 83 Bone Marrow Collection, Handling, Storage, and Transport Tips 83 Supplies for Bone Marrow Collection 84 Smear Techniques 84 Evaluation 85 Bone Marrow Evaluation 85 Cell Type Identification 86 Interpretation 88 Cytology 88 Cytology Collection, Handling, Storage, and Transport Tips 88 Collection Techniques 88 FNB Needle and Syringe Selection 89 Smear Techniques 90 Evaluation 91 Cytologic Criteria of Malignancy 92

Figure 4.4: Cytologic Criteria of Malignancy Specific Tumor Cells 94 Interpretation 95 Fecal Cytology 96 Vaginal Cytology 97 Classifying Vaginal Cells 97 Staging the Estrus Cycle 98 Function Tests 98 Hematology 104 Complete Blood Count 105 Hemacytometer Use 108 Calculating a Differential 108 Evaluation 108 RBC Alterations and Morphology 108 WBC Morphology 112 WBC Alterations 113 WBC Left Shift 114 Platelet Morphology 115 Platelet Alterations 115 Coagulation Tests 115 Coagulation Screening 115 Coagulation Tests 116

93

71

Blood Transfusions 119 Crossmatching 119 Blood Typing 120 Immunology and Serology Tests 120 Microbiology 122 Microbiology Collection, Handling, Storage, and Transport Tips 122 4 Collection Techniques 123 Specimen Storage 124 Most Commonly Used Culture Media 125 Culture Media Inoculation and Incubation 126 Evaluation of Culture Growth 127 Staining Solutions and Procedures 127 Staining Problems 130 Bacteria Identification 130 Fungi Identification 133 Parasitology 134 Fecal Collection, Handling, Storage, and Transport Tips 134 Endoparasite Examination Methods 134

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Fecal Flotation Solutions 137 Blood Parasite Examination Methods Ectoparasite Examination Methods

138

139

Figure 4.35: Relative Size of Parasite Eggs Endoparasites

139

Ectoparasites Urinalysis

139

145

147

Urine Collection, Handling, Storage, and Transport Tips 147 Urine Examination/Urinalysis Gross Examination Preparation

147

148

149

Chemistry Strip Examination 149 Sediment Examination 150 Reporting of Bacteria and Sperm 151 Sediment Examination Urine Artifacts

155

151

Key Words and Phrasesa Agglutination Aggregation Anisocytosis Anisokaryosis Anticoagulants Axonemes Axostyle Basophilic Brownian movement Carbohydrate Cellularity Cestode Colorimetric Cornified Crenation Dermatophyte Encephalopathy Enzyme Epithelial Extracellular Extrinsic Fibrinogen Genal combs Globulin, α Globulin, β Globulin, γ Gluconeogenesis Glycoaminoglycans Glycogenolysis Granularity Hemolyzed Hemostasis Heparinized Hepatoid Hydatid cyst Hypercellular Hyperplasia Hyperthenuric Hypocellular Hypochromic Hypoplasia Hypothenuric Inanimate Intermediate host Intracellular Intrinsic Lipemic a

Abbreviations Lyophilized Lysed Lysosomes Macrocytosis Macrokaryosis Mesenchymal Metabolism Microfilariae Mitotic figures Mordant Mucoprotein Nematode Normocellular Normochromic Nucleoli Oncosphere Oncotic Oocyst Operculum Paratenic host Percutaneous Plasma Pleomorphism Poikilocytosis Polychromatophilic Polycythemia Postprandial Prepatent period Preprandial Proglottid Pronotal Protozoa Pyknotic Rickettsiae Rodenticide Roulleaux Serum Sporangium Sporulated Thrombosis Trematode Trophozoite Urolithiasis Vacuoles

μg, microgram μm, micrometer μmol, micromole AchRs, serum antibody against nicotinic ACT, activated clotting time ACTH, adrenocorticotropic hormone ADH, antidiuretic hormone AIHA, autoimmune hemolytic anemia Alk phos, alkaline phosphatase ALP, alkaline phosphatase ALT, alanine aminotransferase APTT, activate partial thromboplastin time AST, aspartate aminotransferase AT, adrenocortical tumors BA, blood agar BMBT, buccal mucosal bleeding time BTT, light blue top tube BUN, blood urea nitrogen CBC, complete blood count CDV, canine distemper virus Cl, chloride CNS, central nervous system CO2, carbon dioxide cPLI, canine pancreatic lipase immunoreactivity DEA, dog erythrocyte antigen DIC, disseminated intravascular coagulation dL, deciliter DM, diabetes mellitus EDTA, ethylenediaminetetra-acetic acid F, Fahrenheit FDP, fibrin degradation product FeLV, feline leukemia virus FIP, feline infectious peritonitis FIV, feline immunodeficiency virus fL, femtoliter FNA, fine needle aspirate FNB, fine needle biopsy FSP, fibrin split product GIT, gastrointestinal tract GRNTT, green top tube GTT, gray top tube HAC, hyperadrenocorticism HCO3, bicarbonate Hct, hematocrit IFA, immunofluorescence

Additional Resources, page IgE, immunoglobulin gamma E IM, intramuscular IMHA, immune-mediated hemolytic anemia IV, intravenous K, potassium kg, kilogram KPO4, potassium phosphate L, liter LTT, lavender top tube MC, MacConkey agar MCHC, mean corpuscular hemoglobin concentration MCV, mean corpuscular volume mEq, milliequivalent mg, milligram Na, sodium ng, nanogram NMB, new methylene blue NSAIDs, nonsteroidal anti-inflammatory drugs PAP, immunoperoxidase test PCR, polymerase chain reaction PCV, packed cell volume PDH, pituitary-dependent hyperadrenocorticism pg, picogram pH, potential of hydrogen PIVKA, protein induced by vitamin K antagonism pmol, picomole PT, prothrombin time PTH, prothrombin time RBC, red blood cell RTT, red top tube SAP, alkaline phosphatase SGOT, serum glutamic-oxaloacetic transaminase SGPT, serum glutamic pyruvic transaminase SST, serum separator tube T3, triiodothyronine T4, tetraiodothyronine TBT, toenail bleeding time TLI, trypsin-like immunoreactivity TP, total protein TRH, thyroid releasing hormone TSH, thyroid stimulating hormone TT, thrombin time TWBC, total white blood cell count U, unit USG, urine specific gravity WBC, white blood cell

Anesthesia, 439 Canine Transmissible Diseases, 38 Disinfectants, 627 Feline Transmissible Diseases, 44 General Medicine, 201 Injections, 348 Oncology, 273 Pharmacology, 567

4

Key words and terms are defined in the glossary on page 631.

CHAPTER 4 / LABORATORY

73

P

4

roficiency in laboratory skills is one of the most important skills of a veterinary hospital. Each clinic will use their laboratory to different levels, but the proper technique and understanding of each procedure should always be maintained for the most accurate results. The key to learning laboratory skills is to be able to recognize the normal. Having a clear understanding of what is normal allows a person to more quickly identify the abnormal. This chapter covers all aspects to laboratory medicine. Each section begins with the proper way to collect, handle, store and transport laboratory samples, followed by the precise steps needed to perform each task. Variation may exist among some protocols depending on a particular laboratory. Laboratory medicine is a critical part of each diagnosis, and this process often begins with the technician.

BLOOD CHEMISTRIES Blood chemistries evaluate the various blood levels to reach an insight into the different bodily functions. The critical part of blood chemistries is the collection and handling of each sample. For example, allowing a blood sample to remain at room temperature may elevate some chemistries and decrease others, leading to a possible incorrect diagnosis, treatment, and outcome. Extreme care and diligence should be taken with each sample to ensure the most accurate results.

Blood Collection, Handling, Storage, and Transport Tips Collection • Blood samples should be collected from a fasted patient, at least 2 hours postprandial, preferably 4–6 hours. Lipemic samples may lead to hemolysis and therefore ↓ RBC counts. Lipemic and hemolyzed samples can also falsely alter measured serum chemistries. • When feasible, enough blood should be collected to run the tests 3 times; this allows for human error, machine error, and dilution if needed. • Venipuncture site and technique significantly contribute to the quality of the sample. • Always remove the needle to the syringe and the stopper of the tube to let the blood run down the inside of the tube. Sticking a needle

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through the rubber stopper contributes to further hemolysis, especially with a <25-gauge needle. Ideally, a vacutainer system should be used to ↓ hemolysis and ensure the correct blood/anticoagulant ratio. Handling • Fill the anticoagulant tubes first to minimize clot formation, ending with the plain tubes. • Gently mix any tube containing an interactive ingredient, to avoid hemolysis. • Blood smears should be made immediately, using fresh blood after blood collection and fanned to facilitate quick drying. (See Skill Box 4.5, Smear Techniques, page 84.) • Blood smears made with an excessive amount of blood will force the feathered edge off the end of the slide, therefore pushing the larger cells off. • Allow blood to clot in an upright position to prevent cells from sticking to the rubber stopper and hemolyzing during centrifuging. • Remove serum from contact with the cells within 30–45 minutes, to prevent altered laboratory results. • Each tube should be clearly labeled with the patient’s full name, date, and time of collection. Storage • If a sample will not be evaluated in 4–6 hours, the plasma or serum should be poured off and refrigerated. • Blood smears should be dried completely to avoid the formation of condensation inside the slide container and subsequent damage of cellular morphology. • Blood smears should be made and stored at room temperature; refrigeration may cause condensation therefore damaging the cellular morphology. • Do not freeze whole blood, because this causes hemolysis. • Samples to be frozen should be immediately placed in an ice bath, centrifuged, transferred into a plastic tube, and frozen. Transport • Wrap ice packs or blood tubes with paper towels or newspapers to avoid direct contact and subsequent hemolysis.

Table 4.1 / Blood Collection Tubes Tube

Contents

Uses

General Information

• Glucose determinations

• Prevents RBCs from metabolizing glucose by inhibiting enzymes in the glycolytic pathway to more accurately measure blood glucose concentrations than an SST or RTT (e.g., diabetes mellitus and insulinoma)

Whole Blood (unclotted) or Plasma Samples • Immediately invert tubes 6–10 times to prevent coagulation. Gray top tube (GTT)

• Potassium oxalate and Sodium fluoride

4

Green top tube (GRNTT)

• Lithium heparin

• Lead determinations

• Binds with lead • Not appropriate for cell morphology

Lavender top tube (LTT)

• EDTA

• Hematology smears

• Does not alter cell volume or morphology

Light blue top tube (BTT)

• Buffered sodium citrate

• Coagulation determinations

• Measures clotting time (e.g., von Willebrand’s disease, warfarin poisoning, activated partial thromboplastin time [APTT], prothrombin time [PT]) • Must be a perfect venipuncture stick to avoid activation of coagulation pathways • Tube must be filled to ensure proper dilution of blood with anticoagulant.

Serum Samples • Invert tube to activate clotting, stand upright for 20 minutes, and then centrifuge for 15 minutes to ensure proper separation. Serum separator tube (SST), red/gray swirl top

• Clot activator polymer gel

• Blood chemistries

• Serum is not able to mix with clotted blood once centrifuged. • The clotting activator can interfere with some lab tests (e.g., phenobarbital levels).

Red (RTT)

• Plain

• Blood chemistries, serology, and blood banking

• Serum and clotted blood can resuspend if the tube is tilted. • Serum should be separated after centrifugation to a separate plain container. • Glucose is metabolized at approximately 10% per hour when left in contact with cells.

Tip: To determine the amount of fluid in a sample, evaluate a well-hydrated patient’s packed cell volume (PCV). A PCV of 50% will yield a sample with 50% cells and 50% fluid. Therefore, a 10-mL sample will yield 5 mL fluid.

CHAPTER 4 / LABORATORY

75

Table 4.2 / Blood Chemistries Chemistry

Definition

Normal Range

Associated Conditions

Handling and Special Considerations

Alanine Aminotransferase (ALT, SGPT)

Source • Major: hepatocytes • Minor: cardiac muscle, skeletal muscle, pancreas Role • Amino acid metabolism Notes • Liver specific • There is a correlation between ALT levels and hepatic cell damage, but not liver function. • ↑ ALT often seen 2–3 days after hepatic insult and resolves by 14 days

Canine/Feline • 5–65 U/L

↑ Cholangitis/cholangiohepatitis, congestive heart failure, diabetes mellitus, dilated cardiomyopathy, canine/feline, ehrlichiosis, endocardiosis, exocrine pancreatic insufficiency, feline hypertrophic cardiomyopathy, hepatic disease/ failure, hepatic lipidosis, hyperadrenocorticism, hyperparathyroidism, hypertension, hyperthyroidism, hypoadrenocorticism, pancreatitis, peritonitis, pyometra, Rocky Mountain spotted fever, thrombocytopenia, toxoplasmosis

Handling • Hemolysis and lipemia; ↑ values Storage • Room temperature or refrigerator for 24 hours • 2 days at 68° F • 1 week at 32°–39° F • Do not freeze sample. Notes • Corticosteroids and anticonvulsants; ± ↑ values (canine)

Albumin

Source • Hepatocytes Role • Maintain osmotic pressure by retaining fluid within the vascular compartment. • Binding and transport protein Notes • Edema and effusions = ↓ values • 35–50% of total plasma protein • Best interpreted with globulin levels

Canine • 2.3–4.0 g/dL Feline • 2.6–4.0 g/dL Danger level • 1.0

↑ Rocky Mountain spotted fever ↓ Brucellosis, cholangitis/ cholangiohepatitis, ehrlichiosis, heartworm disease, hepatic disease/ failure, hepatic lipidosis, glomerular disease, hyperglobulinemia, hypertension, inflammatory bowel disease, pleural effusion, protein losing enteropathy, toxoplasmosis

Handling • Extreme hemolysis and lipemia; ↑ values Storage • Keep sample covered to prevent dehydration; ↑ values • 1 week at 68° F • 1 month at 32–39° F Notes • Ampicillin; ± falsely ↑ values

Albumin-to-Globulin Ratio (A : G ratio)

Source • See Albumin and Globulin Role • See Albumin and Globulin Notes • First indicator of protein abnormality • Divide the albumin concentration by the globulin concentration.

Canine • 0.6–1.2 Feline • 0.5–2.0

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Handling • See Albumin and Globulin Storage • See Albumin and Globulin Notes • See Albumin and Globulin

Table 4.2 / Blood Chemistries (Continued) Chemistry

Definition

Normal Range

Associated Conditions

Handling and Special Considerations

Alkaline Phosphatase (Alk phos, ALP, SAP)

Source • Major: liver (adult animals), bone (young animals) • Minor: kidneys, intestines Role • Assist in various chemical reactions Notes • Canines can often handle a 2–4-fold ↑ in value before significant signs of disease. • Interpretation is slightly different between canines and felines because of half-lives and amount of hepatic ALP present.

Canine • 10–84 U/L Feline • 10–70 U/L

↑ Cholangitis/cholangiohepatitis, congestive heart failure, diabetes mellitus, drugs (glucocorticoids, barbituates, etc.), ehrlichiosis, hepatic disease/failure, hepatic lipidosis, hyperadrenocorticism, hyperparathyroidism, hypertension, hyperthyroidism, pancreatitis, pyometra, Rocky Mountain spotted fever, thrombocytopenia, toxoplasmosis

Handling • Do not use EDTA or oxalate coagulants. Storage • At room temperature >24 hours; ↑ values • 8 days at 32°–39° F Notes • N/A

Ammonia

Source • Liver and muscle Role • Byproduct of the breakdown of proteins, amines, amino acids, nucleic acids, and urea Notes • N/A

Canine • 45–120 μg/dL Feline • 30–100 μg/dL Danger level • >1,000 (canine)

↑ Cholangitis/cholangiohepatitis, hepatic disease/failure, hepatic lipidosis

Handling • Heparinized sample preferred • Centrifuge and pour off plasma immediately. Storage • Store on ice and assay within 1 hour. • Freeze immediately and assay within 2 days. Notes • Vein occlusion for an extended period or strenuous exercise; ↑ values • Antibiotics, enemas, lactulose, diphenhydramine, parenteral amino acids, narcotics, diuretics, or blood transfusions may alter laboratory results.

Amylase

Source • Major: pancreas • Minor: liver and small intestines Role • Breakdown of starches and glycogen in sugars Notes • ↑ values are not always indicative of severity of disease nor specific for pancreas

Canine • 300–1,500 units Feline • 500–1,500 units

↑ Pancreatitis, peritonitis, chronic renal failure, toxoplasmosis

Handling • Hemolysis; ↑ values • Lipemia; ↓ values • Do not use EDTA Storage • 7 days at 68° F • 1 month at 32°–39° F Notes • Corticosteroids; ± ↓ values • Saccharogenic method; ± false ↑ values (canine)

CHAPTER 4 / LABORATORY

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4

Table 4.2 / Blood Chemistries (Continued) Chemistry

Definition

Normal Range

Anion Gap (AG)

Source • N/A Role • To differentiate causes of metabolic acidosis Notes • To calculate: (Na+ − K+) − (Cl− + HCO3−) = AG

Canine • 12–25 Feline • 13–25

Aspartate Aminotransferase (AST, SGOT)

Source • Major: hepatocytes • Minor: cardiac and skeletal muscles, kidneys, pancreas and erythrocytes Role • Amino acid metabolism Notes • Not liver-specific; ↑ values may indicate liver damage, strenuous exercise, IM injections • Tends to parallel ALT values when caused by hepatic disease

Canine • 16–60 U/L Feline • 26–43 U/L

↑ Cholangitis/cholangiohepatitis, congestive heart failure, diabetes mellitus, endocardiosis, feline dilated cardiomyopathy, feline hypertrophic cardiomyopathy, hepatic disease/ failure, hepatic lipidosis, hyperthyroidism, hypoadrenocorticism, peritonitis, toxoplasmosis

Handling • Hemolysis and lipemia; ↑ values Storage • 2 days at 68° F • 2 weeks at 32–39° F Notes • N/A

Bicarbonate (Venous TCO2)

Source • All cells Role • Aids in transport of CO2 from tissues to the lungs • Bicarbonate/carbonic acid buffer system Notes • 95% of total CO2 measured

Canine/Feline • 21–31 mEq/L

↓ Metabolic acidosis, acute renal failure

Handling • Chill in ice water to prevent alteration of acid–base composition. Storage • Do not freeze, as it results in hemolysis. Notes • N/A

Bilirubin

Source • Hemoglobin via liver processing Role • N/A Notes • Byproduct of erythrocyte degradation • Total bilirubin is composed of conjugated and unconjugated bilirubin. • Not liver specific

Canine/Feline • 0.0–0.5 mg/dL

↑ Cholangitis/cholangiohepatitis, hepatic disease/failure, hemobartonellosis, hemolytic anemia, hepatic lipidosis, hyperthyroidism, pancreatitis, peritonitis, toxoplasmosis

Handling • Lipemia; ↑ values Storage • Not stable when stored in the light or at 68° F • 2 weeks at 32–39° F in the dark Notes • Total bilirubin may ↓ by 50%/hr with direct exposure to sunlight or artificial light.

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Associated Conditions

Handling and Special Considerations Handling • Refer to N.a, K., Cl−, and HCO3− Storage • Refer to N.a, K., Cl−, and HCO3− Notes • Drugs used in combination may blunt the gap ↑.

Table 4.2 / Blood Chemistries (Continued) Chemistry

Definition

Normal Range

Associated Conditions

Handling and Special Considerations

Blood Urea Nitrogen (BUN, SUN)

Source • Amino acids via liver processing Role • N/A Notes • Byproduct of amino acid breakdown • 75% of the kidney must be nonfunctional before ↑ values are seen

Canine • 6–29 mg/dL Feline • 10–35 mg/dL

↑ Canine/feline dilated cardiomyopathy, congestive heart failure, cystic calculi, ehrlichiosis, endocardiosis, hepatic disease/failure, hypertension, hyperthyroidism, hypoadrenocorticism, mastitis, pancreatitis, pyelonephritis, renal failure, Rocky Mountain spotted fever ↓ Cholangitis/cholangiohepatitis, hepatic disease/failure, hepatic lipidosis, overhydration, dietary protein restriction

Handling • N/A Storage • 8 hours at 68° F • 10 days at 32–39° F Notes • 18-hour fast is recommended, because high-protein diets can cause ↑ values

Calcium

Source • Bones Role • Maintenance of neuromuscular excitability and tone • Inorganic ion transfer across cell membranes • Blood coagulation Notes • Hemoglobin and bilirubin; ↑ values with colorimetric test methods • Hypoalbuminemia; ↓ values

Canine/Feline • 8.0–12.0 mg/dL Danger level • ≤7.0 mg/dL or ≥16.0 mg/dL

↑ Hyperparathyroidism, hypoadrenocorticism, neoplasia, renal failure ↓ Dystocia, eclampsia, hypoparathyroidism, pancreatitis, protein losing enteropathy, renal failure

Handling • Hemolysis and contact with cork stoppers; ↓ values • Lipema; ↑ values • Citrate, oxalate, or EDTA anticoagulants; ↓ values Storage • 10 days at 68° F or 32–39° F Notes • N/A

Chloride

Source • Extracellular fluid Role • Acid-base balance • Maintenance of water distribution • Osmotic pressure in blood Notes • Hemoglobin and bilirubin; ↑ values with colorimetric test methods • Tends to parallel serum sodium

Canine • 100–115 mEq/L Feline • 117–128 mEq/L

↑ Metabolic acidosis ↓ Canine dilated cardiomyopathy, constipation, aggressive diuretics, severe emesis, Rocky Mountain spotted fever

Handling • Hemolysis and lipemia; ↓ values Storage • Stable if separated from blood cells Notes • Potassium bromide, acetazolamide, ammonium chloride, androgens, cholestyramine, lithium, demeclocycline and amphotericin; ↑ values

CHAPTER 4 / LABORATORY

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79

Table 4.2 / Blood Chemistries (Continued) Chemistry

Definition

Normal Range

Associated Conditions

Handling and Special Considerations

Cholesterol

Source • Major: hepatocytes • Minor: adrenal cortex, ovaries, testes and intestinal epithelium Role • Steroid hormone production Notes • Helpful in screening for hypothyroidism and Cushing’s disease

Canine 150–275 mg/dL Feline 75–175 mg/dL

↑ Diabetes mellitus, hepatic disease, failure, hyperadrenocorticism, hypertension, hypoadrenocorticism, hypothyroidism, pancreatitis, Rocky Mountain spotted fever ↓ Drugs, exocrine pancreatic insufficiency, hepatic disease/failure, protein losing enteropathy

Handling • Hemolysis, fluoride, and oxalate; ± ↑ values, depending on testing method Storage • Very stable at 68° F if separated from blood cells Notes • Corticosteroids; ± ↑ values

Creatine Kinase (CK)

Source • Cardiac and skeletal muscle and brain tissue Role • Enzyme that cleaves creatine in muscle for energy utilization Notes • Peaks 6–12 hours after muscle injury and returns to normal in 24–48 hours unless damage is ongoing • Very specific, but almost too sensitive • Only large ↑ are clinically significant (≥10,000 U/L) or chronic elevations (≥2,000 U/L) indicating ongoing muscle damage

Canine/Feline • 50–300 U/L

↑ Encephalitis, feline dilated cardiomyopathy, feline hypertrophic cardiomyopathy, hypothyroidism, myasthenia gravis, polymyositis

Handling • Severe hemolysis, icterus, IM injections; ↑ values • EDTA, citrate, fluoride, exposure to sunlight, and delayed analysis; ↓ values Storage • Not stable, do not freeze; analyze as soon as possible Notes • Exercise, recumbency, IM injections; ± ↑ values

Creatinine

Source • Skeletal muscle Role • N/A Notes • Byproduct of creatine degradation • 75% of the kidney must be nonfunctional before ↑ values are seen

Canine • 0.6–1.6 mg/dL Feline • 1.0–2.0 mg/dL

↑ Canine/feline dilated cardiomyopathy, congestive heart failure, drugs, ehrlichiosis, endocardiosis, hypertension, hyperthyroidism, hypoadrenocorticism, severe muscle damage, pancreatitis, pyelonephritis, renal failure, Rocky Mountain spotted fever, toxoplasmosis

Handling • N/A Storage • 1 week at 86–98.6° F Notes • Exercise, active muscle wasting, and meal containing meat; mild ↑ values

Fibrinogen

Source • Hepatocytes Role • Clot formation Notes • No fibrinogen found in serum, because it is removed from the plasma by the clotting process • Used mostly in cattle and horses

Canine • 100–245 mg/dL Feline • 110–370 mg/dL

↑ Cholangitis/cholangiohepatitis, hepatic failure, severe inflammation ↓ DIC, liver failure/end stage

Handling • Heparin; ↓ values Storage • Several days at 68° F • Several weeks at 32–39° F Notes • N/A

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Table 4.2 / Blood Chemistries (Continued) Chemistry

Definition

Normal Range

Associated Conditions

Handling and Special Considerations

Gamma Glutamyltranspeptidase (GGT)

Source • Major: hepatocytes • Minor: kidneys, pancreas, intestines, and muscle cells Role • Enzyme: function unknown Notes • Values typically parallel ↑ in ALP; can be less influenced by secondary nonhepatic conditions or enzymeinducing drugs • Slightly more sensitive and specific for feline hepatic disease than canine

Canine • 2–10 U/L Feline • 1–8 U/L

↑ Anterior uveitis, brucellosis, deep pyoderma, ehrlichiosis, feline immunodeficiency virus, hepatic disease/failure, meningitis, pleural effusion, pyometra

Handling • N/A Storage • 2 days at 68° F • 1 week at 32–39° F Notes • Corticosteroids or anticonvulsant therapy; ± ↑ values

Globulins

Source • α-Globulins: hepatocytes • β-Globulins: hepatocytes • γ-Globulins: plasma cells Role • α- and β-globulins: transport and bind proteins • γ-Globulins: antibody Notes • Total serum globulin concentration = total serum protein concentration − albumin concentration

Canine • 2.7–4.4 g/dL Feline • 2.6–5.1 g/dL

↑ Diabetes mellitus, hepatic failure, hyperadrenocorticism, hypertension, hyperthyroidism, immune mediated disease, neoplasia, pancreatitis, polyconal gammopathies, renal failure, acute ↓ Acute blood loss, heartworm disease, protein losing enteropathy/ nephropathy

Handling • Hemolysis and lipemia; ↑ values Storage • See Albumin and Total Protein Notes • Dehydration; ↑ values • Neonatal animals are 60–80% of adult values; ↓ values

Glucose

Source • Dietary intake and gluconeogenesis or glycogenolysis by the liver Role • Cellular energy Notes • Indicator of carbohydrate metabolism or endocrine function of the pancreas

Canine • 65–130 mg/dL Feline • 70–125 mg/dL Danger level • ≤60 mg/dL

↑ Diabetes mellitus, hypertension, hyperthyroidism, hyperadrenal, hypoparathyroidism, pyelonephritis, renal failure ↓ Dystocia, hepatic failure, failure, hypoadrenocorticism, insulinoma, neoplasia, peritonitis, sepsis

Handling • GTT at 6–10mg/mL of blood as a glucose preservative Storage • Separate from blood cells immediately (<30 minutes) • 8 hours at 68° F • 72 hours at 32–39° F Notes • 16–24-hour fast is recommended, except if hypoglycemia suspected • Glucose levels can drop by 10%/hr if not separated from the blood cells • Stress; ↑ values

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Table 4.2 / Blood Chemistries (Continued) Chemistry

Definition

Normal Range

Associated Conditions

Handling and Special Considerations

Inorganic Phosphorus

Source • Bones Role • Energy storage, release, and transfer, carbohydrate metabolism and composition Notes • Inversely related to calcium

Canine • 3.0–7.0 mg/dL Feline • 3.5–6.1 mg/dL

↑ Bone lesions, chronic renal failure, toxins ↓ Emesis/diarrhea, fanconi syndrome, hepatic lipidosis, hyperparathyroidism, hypoadrenocorticism

Handling • Hemolysis and lipemia; ↑ values Storage • Separate from blood cells immediately • 3–4 days at 68° F • 1 week at 32–39° F Notes • Anabolic steroids, furosemide, mannitol, minocycline, and IV KPO4 may alter values

Lipase

Source • Pancreas and gastric mucosa Role • Break down the long-chain fatty acids of lipids Notes • Value is not representative of severity of disease • Tends to parallel serum amylase

Canine • 0–425 units Feline • 0–200 units

↑ Pancreatitis, hyperadrenocorticism, liver disease, renal disease, failure

Handling • Lipemia; ↑ values • Do not use calcium-binding anticoagulants Storage • 1 week at 68° F • 3 weeks at 32–39° F Notes • Corticosteroids; ± ↑ values

Lipids/Triglycerides

Source • Diet; intestinal absorption Role • Fat metabolism • Stimulus of intestinal lymph flow Notes • Animals at an ↑ risk are obese, high dietary intake of fats and genetic predisposition (e.g., Miniature Schnauzer and Himalayan cats

Canine • 50–150 mg/dL Feline • 17–50 mg/dL Danger level • >1,000 mg/dL

↑ Diabetes mellitus, hyperlipidemia, hypothyroidism, pancreatitis, postprandial ↓ Lymphangectasia, protein-losing enteropathy

Handling ↑ Lipemia; ↑ values Storage • N/A Notes • 12-hour fast recommended

Magnesium

Source • Bones Role • Activator of enzyme systems and involved in production and decomposition of acetylcholine Notes • ↑ Bilirubin can cause ↑ values of magnesium

Canine • 1.8–2.4 mg/dL Feline • 2.0–2.5 mg/dL Danger Level • <1.0 or >10.0 mg/dL

↑ Hypoadrenocorticism, renal failure ↓ Metabolic conditions

Handling • Hemolysis and metal containers; ↑ values • Only heparin anticoagulants should be used. Storage • Samples are very stable. Notes • N/A

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Table 4.2 / Blood Chemistries (Continued) Chemistry

Definition

Normal Range

Associated Conditions

Handling and Special Considerations

Potassium

Source • Intracellular fluid Role • Muscular function, respiration, cardiac function, nerve impulse transmission, and carbohydrate metabolism Notes • N/A

Canine • 4.0–5.7 mEq/L Feline • 4.0–5.8 mEq/L Danger level • ≤2.5 or ≥7.5 mEq/L

↑ Diabetes mellitus, hypoadrenocorticism, massive tissue trauma, acute renal failure, urethral obstruction ↓ Canine/feline dilated cardiomyopathy, congestive heart failure, constipation, diabetes mellitus, gastrointestinal losses, hepatic lipidosis, peritonitis, renal failure

Handling • Hemolysis (esp. Akitas) and refrigeration of an nonseparated sample; ↑ value Storage • Do not freeze nonseparated samples. • Stability is not known. Notes • Plasma is the preferred sample.

Sodium

Source • Extracellular fluid Role • Water distribution, body fluid osmotic pressure maintenance, and pH balance Notes • “Pseudohyponatremia” seen in cases of hyperlipidemia or severe hyperproteinemia

Canine • 140–158 mEq/L Feline • 145–160 mEq/L

↑ Dehydration, heat stroke ↓ Canine dilated cardiomyopathy, congestive heart failure, gastrointestinal losses, hypoadrenocorticism, chronic renal failure, Rocky Mountain spotted fever

Handling • Heparin; ↑ value • Hemolysis; ↓ value Storage • Stability is not known. Notes • Diuretic drugs; ↓ value

Total Protein (TP)

Source • See Albumin and Globulins Role • Oncotic blood pressure, transport mechanism, and immunity Notes • Composed of albumin and globulins

Canine • 5.4–7.6 g/dL Feline • 6.0–8.1 g/dL

↑ Dehydration, gammopathy ↓ Acute blood loss, overhydrated

Handling • Severe hemolysis and sample dehydration; ↑ value Storage • Keep sample covered to prevent dehydration. • Stability is not known. Notes • See Albumin and Globulins

BONE MARROW EVALUATION Bone marrow evaluations can be used to diagnose, to stage certain neoplasias, or to monitor conditions and the body’s response to treatments. The collection and preservation of bone marrow samples are critical to producing diagnostic slides. Properly collected and prepared slides are often evaluated in-house for a preliminary diagnosis before receiving a confirmation from a cytopathologist.

Bone Marrow Collection, Handling, Storage, and Transport Tips Collection • Bone marrow samples degenerate rapidly after collection: neutrophils are the first to take on morphologic changes resembling neoplasia. • Samples should be obtained and prepared within 30 minutes of an animal’s death. CHAPTER 4 / LABORATORY

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Skill Box 4.1 / Supplies for Bone Marrow Collection • Surgical preparation materials

• Place bone marrow aspirate immediately into an EDTA lavender top tube if slides cannot be made immediately.

• Sterile surgical supplies (e.g., gloves, drapes)

• Smears must be made within 30 seconds if an EDTA/isotonic solution is not used, to avoid clotting and cell morphology distortion.

• Analgesic/anesthetic drugs

• Allow the slides to air dry. • Samples must be stained as soon as possible to retain accurate morphology.

3

• 16–18 gauge, 1–1 /4-inch bone marrow biopsy needle

4

Handling

• Scalpel blade

• Staining typically requires 2 times the usual stain contact time to reach adequate staining.

• 12 or 20 mL syringe • Clean microscope slides • 10–20 mL syringe with 2–3% EDTA/isotonic fluid solution Tip: Injecting 0.35 mL isotonic solution into a 7-mL EDTA blood collection tube produces 0.42 mL of 2.5% EDTA/isotonic fluid solution.

Skill Box 4.2 / Smear Techniques Technique

Definition/Uses

Procedure

General Information

Smear Without EDTA

• Samples collected using a clean, dry syringe

1. Hold a slide at a 45–70° angle. 2. Drip the marrow sample down the tilted slide, allowing the marrow flecks to adhere to the slide. 3. With the first slide laying flat, place a second slide on top, allow the drop to spread, and gently pull each slide horizontally in opposite directions. 4. Slides are air-dried and then stained.

• Sample must be smeared within 30 seconds of collection.

Smear With EDTA

• Samples collected using an EDTA/ isotonic solution–filled syringe

1. Sample collected into an EDTA/isotonic solution syringe is expelled onto a Petri dish. 2. Tilt the Petri dish to allow the fluid to drain to the bottom and the marrow flecks to remain adhered to the dish. 3. Using a PCV tube, collect a marrow fleck/spicule and gently place it on a glass slide. 4. Place a coverslip at a 45° angle on the slide so that the corner of the coverslip hangs off the slide. 5. Pull the corner of the coverslip to make a smear of the marrow fleck. 6. Slides are air-dried and then stained.

• Sample must be smeared within a few minutes of collection.

Note: Make some slides using no pressure and some using gentle digital pressure placed on the coverslip.

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1. Prepare a slide with stain.

Storage

2. Scan the slide, using ×4 magnification.

• Slides need to be completely dry before placing in a slide holder.

a. b. c. d.

Transport • Padding should be placed around both sides of the slide holder to prevent breakage (e.g., bubble wrap, padded envelopes). • Do not mail slides with bottles containing formalin, because the fumes may alter the staining capabilities of the slides.

Verify adequate staining. Verify proper slide preparation. Determine the cellularity. Determine the quantity and maturation of megakaryocytes.

3. Examine the slide, using ×10 magnification. a. Cell size b. Cell type

Evaluation

4

4. Examine the slide, using ×40 magnification.

An air-dried slide should quickly be evaluated with new methylene blue to verify the presence of marrow elements (e.g., megakaryocytes) and its diagnostic quality. If the slide is not adequate, further samples should be taken. Once quality slides are available, a stepwise approach should be taken to ensure a thorough evaluation is completed.

a. Chromatin pattern b. Nucleoli 5. Examine the slide, using oil immersion magnification. a. Myeloid:erythroid ratio

Table 4.3 / Bone Marrow Evaluation Definition

Examination

Classification

Cellularity

Proportion of cells compared to fat cells

Low power (×4–10)

Proportion • Normocellular: 30–70% • Hypercellular: >50–70% • Hypocellular: <30–50%

Megakaryocytes

Quantity, maturation, and morphology

Low power (×4–10)

Quantity • Hypoplasia: <3/large fleck • Hyperplasia: >50/large fleck Maturation • Mature: >50%

Erythrocytes

Quantity, proportions, and morphology

Low and high power (×10–100)

Quantity • Rubricyte: 60–70% • Metarubricyte: 30–35% • Prorubricyte: 2% • Rubriblast: <1% Morphology • Karyolysis, pyknosis of immature cells, cytoplasmic or vacuolation, megaloblastic change

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Table 4.3 / Bone Marrow Evaluation (Continued) Examination

Classification

Granulocytes

Quantity, proportions, and morphology

Low and high power (×10–100)

Quantity • Metamyelocyte, band neutrophils, segmented neutrophils: 80% • Myeloblast, promyelocyte, myelocyte: 20% Morphology • Basophilic cytoplasm, vacuolation

Myeloid:Erythroid Ratio

300–500 cells are evaluated in differing areas and classified as either myeloid or erythroid

High power (×100)

• Normal: slightly > 1 : 1

Organisms

Identification

High power (×100)

• Microorganisms: Histoplasma capsulatum, Toxoplasma gondii, Cytauxzoon felis, Erlichia sp. • Parasites: Mycoplasma sp., Babesia sp.

Note: Lymphocytes, plasma cells, monocytes, macrophage, and iron storage can also be evaluated.

Table 4.4 / Cell Type Identification (See Figure 4.1, 4.2, and 4.3, CP-3) Cell Type

Erthyrocytes

4

Definition

86

Appearance

Rubriblast

• • • •

1–2 Blue nucleoli Large, round, dark purple nucleus with smooth edges Fine granular, linear chromatin Distinct blue tint

Prorubricyte

• • • •

Smaller than rubriblasts Round nucleus with smooth edges Coarse and thickened chromatin Reddish tinge

Rubricyte

• • • •

Smaller than prorubricyte Dark clumps of coarse chromatin that begin to disappear Disappearing nucleoli Redder

Metarubricyte

• Larger than a mature RBC • Very dark, pyknotic nucleus • Chromatin and nucleoli are gone

Reticulocyte

• • • •

SECTION THREE: DIAGNOSTIC SKILLS

Large Nonnucleated Basophilic stippling when stained Residual, nonfunctional RNA

Table 4.4 / Cell Type Identification (See Color Plates 4.1, 4.2, and 4.3) (Continued) Cell Type Myeloblast

• • • • •

Large Nongranular, blue–pink cytoplasm Round to oval, red nucleus Chromatin with stippled pattern 1–2 pale blue nucleoli

Progranulocyte/Promyelocyte

• • • •

↑ Cytoplasm with small, pink granules Dark nucleus Chromatin is dark and lacy in pattern ± Nucleoli

Myelocyte

• • • •

Metamyelocyte

• Indented or U-shaped nucleus • Cytoplasm stains light blue • Can be confused with monocytes of peripheral blood

Band

• U-shaped nucleus with smooth edges • ± Chromatin clumps present • Cytoplasm stains light blue

Megakaryoblast

• Not commonly distinguished in bone marrow samples because of size and number present • 2 reddish nuclei • Small amount of basophilic cytoplasm

Promegakaryoblast

• Dividing nuclei • Deep blue cytoplasm • 2–4 Nucleoli

Megakaryocyte

• Extremely large • Abundant, deep blue to pale blue granular cytoplasm • >4 Nucleoli

Granulocyte Platelet

Appearance

4

Oval nucleus Chromatin is dense with a coarse pattern Cytoplasm stains gray–blue Granules take on stain • Eosinophil—red granules • Canine: pleomorphic • Feline: rod-shaped • Basophil—blue granules • Canine: round, red–purple, and few to many • Feline: oval, lavender, and fill cytoplasm • Can be confused with monocytes of peripheral blood

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Interpretation

4

Once a slide has been evaluated, the results are interpreted in conjunction with the results of the complete blood count (CBC). Interpretation may lead to a definitive diagnosis or be just 1 more step in the diagnostic path. Depending on the findings, additional tests may be indicated or an initial treatment plan may be established. Even though the preliminary diagnosis can be made by the veterinarian, it is recommended that these slides be sent to a cytology laboratory for confirmation and staging by a board-certified clinical pathologist/hematologist.

cinoma), the stage of disease, and its prognosis. Although the final diagnosis must lie in the hands of the veterinarian, the technician may make crucial evaluations and interpretations of the slide material, aiding the veterinarian in the diagnosis.

Cytology Collection, Handling, Storage, and Transport Tips Collection • Multiple collection attempts at multiple sites from the lesion should be made to ensure a representative sample. • Adequate pressure must be used with fine-needle aspiration (FNA) to ensure retrieval of cells.

CYTOLOGY Cytology is performed in a clinical setting on a day-to-day basis. A technician well trained in cytology can quickly and easily make preliminary findings. These findings may aid in the distinction in the type of cell (e.g., adenocar-

• Excessive negative syringe pressure or prolonged aspiration often leads to blood contamination and nondiagnostic slides. • Several slides should be made to allow different staining techniques.

Skill Box 4.3 / Collection Techniques Technique

Uses

Procedure

Comments

Imprints

• External lesions or fresh tissue samples from a surgical biopsy or necropsy

1. Blot the lesion or area to be imprinted with a clean, dry gauze. 2. Touch the lesion against a clean glass slide to make an imprint. • Can repeat several times on 1 slide. • Imprint ulcers before and after cleaning.

• Typically collects the fewest number of cells with the greatest amount of contamination

Scrapings

• External lesions or tissues from surgical biopsy or necropsy

1. Clean lesion and blot dry. 2. Hold scalpel perpendicular to lesion. 3. Pull the blade toward oneself several times in a scraping motion. 4. Transfer the material to the middle of a glass slide with the scalpel blade and smear.

• Collects a large number of cells and possibly a large amount of bacterial contamination and inflammation

Swabs

• Fistulous tracts and vaginal collections

1. Moisten a sterile swab with saline. 2. Gently roll the swab against the inside wall of the tract or vagina. 3. Gently roll the swab across a slide to transfer material in a thin smear.

• Only alternative for tract-like lesions • ↑ Cell damage with rough or improper handling

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Skill Box 4.3 / Collection Techniques (Continued) Technique

Fine Needle Biopsya

Aspirate

a

Nonaspirate

Uses

Procedure

Comments

• Lesions

1. Isolate and firmly hold the tumor. 2. Insert the needle into the tumor and apply strong negative pressure by pulling the plunger 3/4 of the way back and release pressure. 3. Redirect the needle to a different part of the tumor and again apply pressure; continue this several times in different locations. 4. Quickly smear the contents, using 1 of the smear techniques. (See Skill Box 4.5 Smear Techniques, page 90.) • If the tumor is large enough, negative pressure may be maintained while the needle is being redirected.

• Avoids superficial contamination, but with ↑ contamination of tissues surrounding the tumor during aspiration • ↑ Blood contamination with certain types of tumors • Allows for collection from multiple locations within the lesion

1. Isolate and firmly hold the tumor. 2. Insert the needle only into the tumor and rapidly move the needle up and down while maintaining the same track. 3. Remove the needle and attach an air-filled syringe and quickly expel the contents onto a clean glass slide. 4. Smear the contents, using 1 of the smear techniques. (See Skill Box 4.5 Smear Techniques, page 90.)

• Avoids superficial contamination, but with ↑ contamination of tissues surrounding the tumor during aspiration • Enough material collected for only 1 smear, which may reduce diagnostic yield

• Any mass or solid lesion that is of large enough size to isolate • Ultrasound-guided biopsy of deep tissues • Highly vascular lesions

Fine needle biopsy to the center of a mass typically yields necrotic debris and inflammatory cells, peripheral locations may produce the best results. Difficult in small masses ≤10 mm.

Skill Box 4.4 / FNB Needle and Syringe Selection • The softer the tissue being aspirated, the smaller are the gauge of needle and syringe. • Do not use needles larger than 21 gauge, because they produce core biopsies and have a greater likelihood of blood contamination. • 12-mL syringes are a safe bet for all tumors.

Handling • The material obtained must be prepared and smeared on a slide immediately to avoid drying, clumping, and clotting. • Do not allow the smear to reach the edges of the slide if possible. • Rapidly dry the slide after smearing by waving in the air or using a blow dryer. • Slides should be marked as to which side is the top by using the patient’s information. • 2–3 air-dried unstained slides and 2–3 air-dried stained slides should be prepared when sending to the laboratory. The stained slides are a precaution for those cells that do not hold up well unstained for extended periods. • Fluid samples should be sent with prepared slides if possible. CHAPTER 4 / LABORATORY

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Skill Box 4.5 / Smear Techniques The most common error in cytology is sample handling by the laboratory technician. An improperly prepared slide may contain ruptured cells or areas too thick to read, or the sample may dry before it is smeared. All of these errors may lead to improper evaluation, but they can be remedied by proper technique and care on the part of the laboratory technician.

4

Technique

Definition/Uses

Procedure

Blood Smear Technique

• Produces a thin layer of fluid material across the slide • Fluid samples

1. Expel the aspirate material onto a glass slide. 2. Place the second glass slide at a 30–40° angle to the first slide in front of the material. 3. Pull the second slide back into the material and then gently, but swiftly, push across to the end of the first slide. • Rest the “smearing” slide against a fingertip to push across allows a gentle and smooth movement. • The end of the smear should have a feathered edge and not run off the edge of the slide.

Squash Preparation

• Produces well-smeared slides • Thicker samples (e.g., bone marrow aspirates)

1. Expel the aspirate material onto a glass slide. 2. Place a second glass slide on top of the material at a right angle. 3. Without applying any downward pressure, quickly and smoothly slide the top slide across the bottom slide to smear the material.

Squash-Modified Preparation

• Produces well-smeared slides with a ↓ tendency for cell rupture • Thicker samples (e.g., bone marrow aspirates)

1. Follow steps 1 and 2 above. 2. Rotate the top slide 45° and then lift up.

Combination Technique

• A combination using the squash preparation and the blood smear technique • Any sample

1. Expel the aspirate material onto a glass slide. 2. Mentally divide the material into 3 sections and do a blood smear technique on one third of the slide and a squash preparation on the opposite third.

Starfish Preparation

• Prevents destruction of fragile cells • Any sample

1. Expel the aspirate material onto a glass slide. 2. Using the tip of the needle, spread the material out into the shape of a starfish.

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SECTION THREE: DIAGNOSTIC SKILLS

Storage • Slides need to be completely dry before placing in a slide holder. Transport • Padding should be placed around both sides of the slide holder to prevent breakage (e.g., bubble wrap, padded envelopes). • Do not mail slides with bottles containing formalin, because the fumes may alter the staining capabilities of the slides. • Protect the slides from moisture as the sample may become distorted.

Evaluation Once each slide has been properly collected and prepared, it is often evaluated in the clinic for a preliminary diagnosis. The technician is an integral part of this procedure by evaluating the slide and noting any alterations. The DVM then confirms the slide contents and makes a preliminary diagnosis. The slide is sent to a reference laboratory for official diagnosis. 1. Prepare a slide with stain. 2. Scan the entire slide using ×4 magnification. a. Verify adequate staining. b. Check for staining features and artifacts.

c. Check for overall cellularity and localized areas of cellularity. d. Check for crystals, foreign bodies, parasites, and fungal hyphae. 3. Examine the slide, using ×10 magnification. a. Cell size b. Cell type c. Cellularity 4. Examine the slide, using ×40 magnification. a. Chromatin pattern b. Nucleoli

4

5. Examine the slide, using oil immersion magnification. a. Cell inclusions b. Cell organisms c. Mitotic figures Tip: Placing a drop of immersion oil on a prepared slide (excluding a wet mount) covered by a coverslip enhances the clarity of the slide contents. To increase magnification to ×100, another drop of immersion oil can be placed on top of the coverslip and examined. To save the slide for later evaluation, the coverslip can be gently slid off horizontally to avoid damaging the slide’s contents.

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Table 4.5 / Cytologic Criteria of Malignancy

Any slide showing 1 or a combination of the following cellular changes should be carefully reviewed for potential malignancy. A cytology laboratory should be consulted for clarification if needed. Nuclear characteristics have proven to be the most reliable source of determining malignancy. However, all aspects of the cells should be evaluated. Some types of malignant cells do not routinely show any of the following characteristics; therefore, all other aspects of the complete workup should be viewed simultaneously.

4

Cytologic Characteristics

Appearance

Tumor Cell Types

Nuclear

• • • • • •

Anisokaryosis Macrokaryosis Variation in nuclear : cytoplasmic ratio Coarse chromatin pattern that clumps Irregular nuclear pattern Abnormal size, shape, and appearance of nucleoli • Irregular nuclear membrane

Epithelial • Round nucleus with a smooth to slightly coarse chromatin pattern and usually centrally located • 1 or more nucleoli Mesenchymal • Oval nucleus and centrally located Round cell • Centrally or eccentrically located

Cytoplasmic

• Vascuolization • Variable amount of cytoplasm from cell to cell • Basophilia with Wright’s stain • Abnormal cytoplasmic boundaries

Epithelial • ↑ Cytoplasm with secretory products or vacuolated Mesenchymal • Abnormal cytoplasmic boundaries and extensions • Moderate amount Round cell • Well-defined cytoplasmic boundaries • Variable amount, granularity, and vacuolization

Structural

• Anisocytosis • Macrocytosis • Pleomorphism

Epithelial • Large to very large cells • Round to oval to caudate cells, easily exfoliating into sheets, clusters, or clumps Mesenchymal • Small to medium cells • Spindle-shaped cells hard to exfoliate • Individual cells or in disorganized clusters Round cell • Small to medium cells • Round to oval cells; easy to exfoliate individual cells

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Table 4.5 / Cytologic Criteria of Malignancy (Continued)

4

Figure 4.4 Cytologic criteria of malignancy. Note: Courtesy of Dina A. Andrews, DVM, Ph.D, DipACVP.

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Table 4.6 / Specific Tumor Cells

The following chart gives a general description of common tumor types. Multiple variations can be seen because of location, duration, and malignancy. Each cell should be evaluated in lieu of the rest of the slide and the general findings of the animal. The diagnosis of a particular condition must be made by the veterinarian. Tumor Type

Epithelial Mesenchymal

Basophilic cytoplasm with ± vacuoles with secretory products Variable nuclear size and nuclear : cytoplasm ratio Nuclei often eccentrically displaced to the periphery of the cells Round to oval cells appearing in clusters Variable nucleolar shape and number

Mammary Adenocarcinoma

• • • • •

Perianal Adenoma

• Hepatoid appearing in clumps • Round to oval nuclei with 1–2 nucleoli • Abundant, foamy, and gray to tan cytoplasm with ± granules

Sebaceous Gland Tumor

• • • •

Squamous Cell Carcinoma

• Basophilic cytoplasm to abundant, pale cytoplasm • Large nuclei with clumped chromatin • Variable nuclear : cytoplasm ratio

Lipoma

• Large cells distended with fat or lacy, collapsed cells

Osteosarcoma

• Variably sized nucleus with clumped chromatin • Spindle-shaped • Abundant, foamy basophilic cytoplasm

Soft Tissue Sarcoma

• Anisocytosis or spindle shaped • Dark blue cytoplasm with ± vacuoles and pink granules • Variable number and size of nucleoli

4

94

Appearance

SECTION THREE: DIAGNOSTIC SKILLS

Large cell Nucleus with a slightly coarse chromatin pattern ↑ Nuclear : cytoplasm ratio ± Basophilic and foamy cytoplasm

Table 4.6 / Specific Tumor Cells (continued)

Round Cell Tumor

Tumor Type

Appearance

Histiocytoma • Color Plate 4.5, CP-4

• • • • •

Anisocytosis Poikilocytosis Variable amount of pale blue cytoplasm ↑ Nuclear:cytoplasm ratio Round, oval, or irregularly shaped nuclei with lacy or finely stippled chromatin pattern

Lymphoma • Color Plate 4.6, CP-4

• • • •

Dense nuclear margins with basophilic cytoplasm ↑ Nuclear:cytoplasm ratio Granular chromatin ≥1 Nucleolus

Mast Cell Tumors • Color Plate 4.7, CP-4

• • • •

Anisocytosis Round to oval nuclei, stain palely Fine to coarse, blue-black to reddish-purple granules within cytoplasm Variable nuclear:cytoplasm ratio depending on differentiation and grade

Melanoma

• Green-black to brown granules that are irregular in shape and size in cytoplasm • Poikilocytosis

Plasma Cell Tumor

• • • •

Interpretation Once a slide has been evaluated, the results should confirm an inflammatory and/or neoplastic process. The distinction of inflammation alone often will enable the veterinarian to determine an initial protocol and treatment plan.

4

Oval to round cells with coarse, clumped chromatin 1 small nucleolus ± Basophilic cytoplasm Nonstaining Golgi apparatus eccentrically placed

If the slide is found to have neoplastic cells, they are then reviewed against the criteria of malignancy. A preliminary diagnosis on cell type, associated disease, and malignancy can be made by the veterinarian. Often, the results are sent to a cytology laboratory for confirmation and staging.

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Table 4.7 / Fecal Cytology

Appearance

Clostridium sp. • Color Plate 4.8, CP-4

• • • •

Giardia • Color Plate 4.9, CP-5

Trophozoites • Pear-shaped with a concave ventral surface • Two outlined nuclei resembling eyes along with a nose and mouth, which are axonemes and median bodies • Forward or “falling leaf” motility • Size: 6–10 μm Cysts • Crescent-shaped indentation when collapsing in fecal float solution • Nuclei, cyst wall, and axonemes seen • Size: 11–13 μm

Curved or Spiral Bacteria

Organism

Yeast

4

Fecal cytology is an important diagnostic tool for identifying inflammatory cells and potentially pathogenic organisms of the GIT. It is indicated in diarrheic animals, either acute or chronic. The first step is to assess the presence and quantity of bacteria. One predominant bacteria may indicate it as an pathogenic organism and a bacterial culture should be pursued. Some conditions may have more than 1 predominant bacteria (e.g., malabsorption, maldigestion). The presence of small numbers of epithelial cells may be found in normal animals. However, the presence of neutrophils or eosinophils may be indicative of inflammatory disease (e.g., Salmonella, Campylobacter sp., eosinophilic colitis). Fecal cytology may also reveal protozoal (e.g., Giardia) or fungal (e.g., Histoplasma sp.) organisms. Fecal cytology is set up in 1 of 2 ways: wet prep or dry prep. See Skill Box 4.16 Endoparasite Examination Methods page 134, for further information.

96

Large, gram-positive rods More easily recognized in the sporulated form “Safety pin” appearance, which represents a nonstaining spore within the sporangium (the body of the cell) >5 per ×100 field may indicate overgrowth

Campylobacter • Color Plate 4.10, CP-5

• • • • •

Treponeme and Spirillum Type (true spirochetes) • Color Plate 4.11, CP-5

• Gram-negative • Stiff corkscrew helical rods with tight spirals • Corkscrewing motility

Brachyspira

• Looser, sinusoid, thin spirals • Rapid, nematode-like movement; when attached to shed epithelial cells in large numbers resemble flagella

Trichomonas sp.

• Single nucleus and undulating membrane • Rolling and erratic motility, flexing axostyle visible, jerky movement • Can be confused with Giardia (feline; diarrheic)

Candida-like • Color Plate 4.12, CP-5

• Rarely internal structures; smaller than Giarda cysts

Cyniclomyes (Sarrharomycopsis)

• Large elongated yeast with bipolar inclusions; sometimes see branching

SECTION THREE: DIAGNOSTIC SKILLS

Gram-negative Tiny, curved, gram-negative rods (not tightly spiraled) Two attached together as a “seagull” or “W” shape “Swarm of bees”: rapid and darting motility Size: 1.5–5 μm

Vaginal Cytology Vaginal cytology is used in evaluating an animal’s stage of estrus cycle. Because of the constant changing of cellular structures during the estrus

cycle, the evaluation of vaginal cells should be done every few days and in conjunction with a thorough medical history and examination (e.g., multiple, sequential samples increase accuracy of estrus stage estimation).

Table 4.8 / Classifying Vaginal Cells

Noncornified Squamous Epithelial Cells

Appearance

Parabasal cells

• Small round cells with a small amount of cytoplasm • Round, distinct nuclei • Uniform in size and shape

Intermediate cells

• Large round cells with a large amount of cytoplasm • Round nuclei

Superficial Intermediate cells

• ↑ Cytoplasm that is irregular, folded, and angular • Smaller nuclei, pyknotic

Cornified Squamous Epithelial Cells

Vaginal Cells

4

Superficial cells

• Large cells • ↑ Cytoplasm, folded and angular • Distinct edges As the cell ages • ± Nucleus (nucleated with young cells and anuclear with older/advanced cells) and vacuoles

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Table 4.9 / Staging the Estrus Cycle Estrus Stage

Definition

Cell Appearance

Anestrus

• No physical changes • Does not attract or accept males • Duration: <4.5 months

• Intermediate or parabasal cells • ± Neutrophils • ± Bacteria

Proestrus

• Swollen vulva, bloody vaginal discharge • Attracts, but will not accept males • Duration: 4–13 days

Early • Noncornified squamous epithelial cells • Neutrophils and erythrocytes • ± Bacteria Late • Superficial intermediate cells and cornified epithelial cells • ↓ Neutrophils and ↑ erythrocytes • ± Bacteria

Estrus

• Swollen vulva and pinkish to straw colored discharge • Accepts males • Duration: 4–13 days

Early • 90% Cornified squamous epithelial cells • ± Superficial intermediate cells • ± Erythrocytes • Bacteria Late • ↑ Neutrophils and ↓ erythrocytes • Bacteria

Metestrus/Diestrus

• Vulvar swelling and discharge • Does not attract or accept males • Duration: 2–3 months

Early • Cornified squamous epithelial cells • ↑ Cytologic debris Late • Intermediate and parabasal cells • ± Neutrophils and erythrocytes

4

FUNCTION TESTS Function tests are used to force a system in the body to perform in a specific way (e.g., suppression or stimulation) to provide predictable results. Depending on the results, the information received will help to determine whether the system is functioning correctly. Most of these procedures require

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a specific protocol of fasting, injections, and blood drawing times; however, individual laboratories should be consulted regarding their specific protocol. As with any laboratory test, collection and handling remain the area of biggest human error as well as the area easiest to monitor and perform correctly.

Table 4.10 / Function Tests Test

Definition/Uses

Normal Range

Protocols

Handling and Special Considerations

Adrenocorticotropic Hormone (ACTH) Endogenous Plasma, Concentration

Distinguishes between pituitarydependent hyperadrenocorticism (PDH) and adrenocortical tumors (ATs) and primary and secondary hypoadrenocorticism

Canine • 2.2–25 pmol/L • <2.2 = AT • 2.2–10 = nondx • >10 = PDH

• Fast for 12 hours. • Collect a blood sample.

Handling/Storage • Lipemia; may interfere with the assay • Sample should be immediately placed in an ice bath, centrifuged, transferred into a plastic tube, and frozen. • Send by overnight air on dry ice to testing laboratory. • Aprotinin can be added to the EDTA tube to inhibit the degradation of ACTH and remove the need to freeze sample. Notes • N/A

Tube: LTT Amount: full tube Use: Hyperadrenocorticism, Hypoadrenocorticism

ACTH Stimulation Test or ACTH Response Test Tube: SST or RTT Amount: 0.5 mL serum or plasma each sample

The adrenal gland will respond to exogenous ACTH stimulation by glucocorticoid release in proportion to the glands’ size and development. This test measures actual cortisol hormone.

Canine Pretest: • 0–10 μg/dL Posttest: • 8–22 μg/dL Feline Pretest: • 0.4–4.0 μg/dL Posttest: • 8–12 μg/dL

• Obtain baseline sample. • Cosyntropin • Canines: 0.25 mg IM and felines 0.125 mg IM cosyntropin. • Draw blood sample 1 hour post for canines and 30 minutes and 1 hour post for felines. • ACTH gel • Give 1 unit/lb of ACTH gel IM. • Draw blood sample 2 hours post for canines and 1 and 2 hours post for felines.

Handling/Storage • Delay in separation of serum/plasma from blood cells and lipemia; ↓ values • Sample should be immediately placed in an ice bath, centrifuged, transferred into a plastic tube, and frozen. Notes • Discontinue prednisone, prednisolone, cortisone, and fludrocortisone 24–48 hours before test.

Evaluates the effect of exogenous ADH on the renal tubular ability to concentrate urine in the face of dehydration or water deprivation

Canine/Feline • ↑ in urine specific gravity (USG)

• Immediately after a water deprivation test; give 0.5 U/ kg vasopressin IM (max of 5 U) • Empty the urinary bladder and measure specific gravity and osmolality at 30, 60, 90, and 120 minutes

Handling/Storage • N/A Notes • Withhold all food and water until the test has been completed.

Use: Hyperadrenocorticism, Hypoadrenocorticism; screening and monitoring therapy

ADH Response Test or Vasopressin Response Test Use: Diabetes insipidus; differentiates between central and nephrogenic diabetes insipidus

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4

Table 4.10 / Function Tests (Continued) Test

Definition/Uses

Normal Range

Protocols

Handling and Special Considerations

Ammonia Tolerance Test (ATT)

Detect abnormal portal blood flow and liver dysfunction

Canine Preammonia: • 44–116 μg/L Postammonia: • 85–227 μg/L Danger level • >1,000 μg/dL

• Fast for 12 hours and give enemas to clear lower bowel • Obtain baseline sample • Give ammonium chloride at 0.1 g/kg (max of 3 g) • Orally dissolved in 20– 50 mL water and given by stomach tube • Rectally as a 5% solution • Orally as a powder in gelatin capsules • Draw heparinized blood samples at 30 to 45 (gelatin capsules) minutes post

Handling/Storage • Centrifuged immediately, pour plasma off and analyze within 1–3 hours or freeze at −68° F Notes • Not recommended for felines • Do not perform if resting ammonia levels are already ↑, because it may cause hepatic encephalopathy. • Oral administration may cause regurgitation. • Vomiting may occur but does not invalidate test. • Venous occlusion, vigorous activity before, and muscle exertion during restraint; ↑ values • 3–10-fold ↑ indicates portosystemic shunts

A dysfunctional hepatobiliary system allows ↑ levels of bile acids to be found systemically. This test is a very sensitive function test of hepatic and biliary abnormalities.

Canine/Feline Fasted: • <5 μmol/L Postprandial: • <25 μmol/L

• Fast for 12 hours. • Obtain a baseline sample. • Feed ≥2 Tbsp of a high-fat diet to a dog and ≥1 Tbsp to a cat. • Collect a blood sample 2 hours post.

Handling/Storage • N/A Notes • Ursodeoxycholic acid; altered values • Hemolysis: ↓ values • Ileum disease and large-volume diarrhea; ↓ values

A direct measurement of pancreatic lipase versus the general measurement of total serum lipase activity

Canine • 1.9–82.8 μg/L

• Fast for 12–18 hours. • Collect a blood sample.

Handling/Storage • Separate serum and send sample on ice with a direct carrier to Texas A&M GI Lab. Notes • N/A

Tube: GRNTT Amount: full tube

4

Use: Hepatic disease and portosystemic shunting

Bile Acids Tube: SST Amount: 0.5 mL serum each Use: Hepatic disease, portosystemic shunting, and cholestatic disorders Canine Pancreatic Lipase Immunoreactivity (cPLI) Tube: SST Amount: 0.5 mL serum Use: Pancreatitis and Pancreatic mass

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Table 4.10 / Function Tests (Continued) Test

Definition/Uses

Normal Range

Protocols

Handling and Special Considerations

Dexamethasone Suppression Test High-dose

Differentiates pituitary-dependent hyperadrenocorticism (PDH) from adrenocortical tumors (ATs) in canines. The injected dexamethasone is expected to shut off ACTH production through negative feedback, as seen with PDH. This is also a diagnostic screening test for HAC in felines.

Canine PDH: Pretest: • 1.1–8.0 μg/dL Posttest: • 0.1–1.4 μg/dL or ≤50% of pretest level AT: Pretest: • 2.5–10.8 μg/dL Posttest: • 1.4–5.2 μg/dL

• Obtain a baseline sample. • Give 0.01 mg/kg dexamethasone IV. • Collect a blood sample at 4 (optional) and 8 hours post.

Handling/Storage • N/A Notes • N/A

Used to diagnose or confirm HAC

Canine Pretest: • 1.1–8.0 μg/dL Posttest: • 0.1–0.9 μg/dL • (nondx 1.0–1.4 μg/dL) Feline Pretest: • 1–4 mg/mL Posttest: • <1.5 μg/dL

• Obtain a baseline sample. • Give 0.01 mg/kg (canine) and 0.1 mg/kg (feline) dexamethasone sodium phosphate IV. • Collect a blood sample at 4 and 8 hours post.

Handling/Storage • N/A Notes • Keep felines in a stress-free environment during testing.

Folate is absorbed in the jejunum and cobalamin in the ileum. Reflect intestinal absorptive function and the status of the intestinal flora.

Canine Folate • 3.5–11 μg/L Cobalamin • 300–700 ng/L Feline Folate: • 6.5–11.5 μg/L Cobalamin • 290–1,500 ng/L

• Fast for 12 hours. • Collect a blood sample.

Handling/Storage • Folate hemolysis; ↑ value • Avoid prolonged exposure to light and heat. Notes • N/A

Adjunctive test used to diagnose DM and to monitor glycemic control during insulin therapy

Canine • 370 μmol/L Feline • 375 μmol/L

• Obtain a blood sample.

Handling/Storage • N/A Notes • Corticosteroids, progestins, thiazide diuretics, growth hormone, dextrosecontaining fluids and morphine; ↑ value

Tube: SST Amount: 0.5 mL serum each Use: Hyperadrenocorticism

Dexamethasone Suppression Test Low-dose Tube: SST Amount: 0.5 mL serum each Use: Hyperadrenocorticism

Folate and Cobalamin Tube: SST Amount: 1 mL serum Use: Intestinal bacterial overgrowth, malabsorption, exocrine pancreatic insufficiency, inflammatory bowel disease, or intestinal neoplasia Fructosamine Tube: SST or RTT Amount: 0.5 mL serum Use: Diabetes mellitus

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CHAPTER 4 / LABORATORY

101

Table 4.10 / Function Tests (Continued) Test

Definition/Uses

Normal Range

Protocols

Handling and Special Considerations

Prothrombin Time (PTH, PT)

A vitamin K–dependent coagulation protein (factor) made by the liver. Evaluates extrinsic and common coagulation pathways

Canine • 5–8 sec Feline • 8–11 sec

• Collect a blood sample.

Handling/Storage • Tube must be completely full. • Centrifuge at 3,000 rpm for 10 minutes, remove plasma. • If >24 hours to run test, spin sample, and freeze plasma. Notes • N/A

Identifies an immune response specifically against muscle AchRs.

Canine • <0.6 nmol/L Feline • <0.3 nmol/L

• Collect a blood sample.

Handling/Storage • Separate serum and ship overnight on ice/chilled. Notes • Corticosteroid therapy can lower serum antibody levels.

Evaluates the ability of the thyroid gland to suppress pituitary TSH secretion followed by a drop in T4 secretion.

Canine/Feline • ↓ in serum T4 after 72 hours of oral T3

• Obtain a baseline sample for T4 and T3. • Give 25 μg/cat of T3 orally TID, starting the next morning for 7 doses. • On the morning of the 3rd day, give 25 μg orally of T3 and redraw blood sample within 4 hours for T3 and T4.

Handling/Storage • N/A Notes • Rise in T3 confirms owner’s compliance in giving medication.

Evaluate the resting thyroid hormone concentration, a measurement of the total T4 or T3.

Canine T4: • 1.0–4.0 μg/dL T3: • 0.5–1.8 ng/mL Feline T4: • 1.8–4.5 μg/dL T3: • 0.4–1.6 ng/mL

• Collect a blood sample.

Handling/Storage • N/A Notes • Corticosteroids, illness, estrus, pregnancy, obesity, stress; altered values • T3 is not as accurate in the early stages of disease.

A measurement of thyroid hormone not bound to a protein (unbound) and available for entry into cells

Canine • 0.3–0.5 ng/dL Feline • 0.8–5.2 ng/dL

• Collect a blood sample.

Handling/Storage • N/A Notes • Least likely to be affected by nonthyroidal diseases

Tube: BTT Amount: 1.8 mL whole blood

4

Use: Liver disease and anticoagulant toxicity Serum Antibody Against Nicotinic AchRs Tube: SST Amount: 1 mL serum Use: Myasthenia gravis T3 Suppression Test Tube: RTT Amount: 0.1 mL serum Use: occult Hyperthyroidism

Thyroid Hormone, Basal Serum (T4 and T3) Tube: SST Amount: 1 mL serum Use: Hyperthyroidism, Hypothyroidism

Thyroid Hormone, Free (Free T4 and Free T3) Tube: SST Amount: 0.5 mL serum Use: Hyperthyroidism, Hypothyroidism

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Table 4.10 / Function Tests (Continued) Test

Definition/Uses

Normal Range

Protocols

Handling and Special Considerations

Thyroid-Releasing Hormone (TRH) Stimulating Test or TRH Response Test

TRH is responsible for the release of thyroid-stimulating hormone (TSH) from the anterior pituitary and the eventual synthesis of thyroid hormone. Evaluates thyroid gland function by the degree of change after the administration of TRH.

Canine • >2 μg/dL post-TRH or ≥0.5 μg/dL above baseline T4 Feline • Little to no ↑

• Obtain baseline sample. • Give 0.1 mg/kg TRH IV. • Collect blood sample 4 and 6 hours post (canine) and 4 hours post (feline).

Handling/Storage • N/A Notes • TRH administration typically causes hypersalivation, tachypnea, and vomiting up to 4 hours post-stimulation.

TSH is responsible for stimulating the synthesis of thyroid hormones in the thyroid gland.

Canine • 0.02–0.5 ng/mL

• Collect a blood sample.

Handling/Storage • N/A Notes • N/A

Test of pancreatic digestive function. A ↓ amount of serum TLI is found when there is a ↓ in the amount of functioning pancreatic cells.

Canine • 5–35 μg/L Feline • 17–49 μg/L

• Fast for 12 hours. • Collect blood sample.

Handling/Storage • Allow to clot at room temperature. • Serum is stored at −68° F. Notes • More sensitive and specific for pancreatitis than amylase/lipase

Although urine creatinine stays relatively constant in an animal with stable kidney function, increased urine cortisol levels are seen with hyperadrenocorticism.

Canine • <1.35 × 10−5

• Obtain urine sample. • Determine cortisol and creatinine concentrations.

Handling/Storage • N/A Notes • Avoid stress while obtaining urine sample. • Obtain at home with a morning sample • False positives are common.

To determine the significance of protein in the urine; not dependent on urine concentration

Canine • <0.3 Feline • <0.6

• Obtain urine sample via cystocentesis. • Determine protein and creatinine concentrations.

Handling/Storage • N/A Notes • Performed on a morning sample

Tube: SST Amount: 0.5 mL serum each Use: Hyperthyroidism (feline), Hypothyroidism (canine) Thyroid-stimulating Hormone Concentration (endogenous TSH) Tube: SST Amount: 0.5 mL serum Use: Hypothyroidism Trypsin-like immunoreactivity (TLI) Tube: SST or RTT Amount: 1 mL serum Use: Exocrine Pancreatic Insufficiency, Pancreatitis Urine Cortisol:Creatinine ratio Amount: 3–4 mL urine Use: Hyperadrenocorticism

Urine Protein:Creatinine Ratio Amount: 1 mL Cystocentesis sample Use: Glomerulonephritis and renal disease

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4

Table 4.10 / Function Tests (Continued) Test

Definition/Uses

Normal Range

Protocols

Handling and Special Considerations

Water-Deprivation Test

To dehydrate the body to the point of signaling ADH release and the subsequent concentration of urine by the kidneys

Canine • 1.045 Feline • 1.075 • A USG of 1.025 is considered an adequate response.

• Stop either test when the animal loses ≥5% of body weight, becomes ill, or USG is >1.025. Gradual • Determine unrestricted daily water intake. • Measure USG and weigh animal. • Reduce water intake by 5% daily (not <66 mL/kg/day). • Measure USG and weigh animal daily. Abrupt • Empty urinary bladder and measure USG and weigh animal. • Withhold food and water until the end of the test. • Every 2–4 hours, empty urinary bladder, measure USG, and weigh animal.

Handling/Storage • N/A Notes • Contraindications: dehydration, renal disease, and azotemia • A modified water-deprivation test is the ADH response test immediately after the standard water-deprivation test. • BUN should be monitored regularly throughout both tests.

Use: Diabetes insipidus

4

HEMATOLOGY Even though many clinics send their blood samples out to reference laboratories for evaluation or use in-house automated machines, knowledge of how to perform a manual complete blood count (CBC) can be very useful in certain situations. For example, during emergency situations, when time is crucial, the technician may be asked to perform an in-house CBC—or when the automated machine is malfunctioning. The results will provide the veterinarian with crucial information regarding the patient’s hematology status (e.g., anemia, infection, and neoplasia). See Under Blood Chemistries for Blood Collection, Handling, Storage, and Transport Tips.

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A CBC consists of RBC and WBC evaluation, PCV, TP, hemoglobin (Hgb) concentration, differential, platelet estimate, RBC indices, and a reticulocyte count. These tests are all run using a whole blood sample from an anticoagulant tube, such as EDTA. (See Skill Box 4.1, Blood Collection Tubes, page 74.) The assessment of morphology and cell counts must be performed in a monolayer area of the slide. Thicker areas and the feathered edge should be evaluated for large structures, such as: platelet clumps, microfilaria, and mast cells. Cell inclusions are often confused with platelets and stain precipitate; their location (e.g., within the cell, surface of cell) should always be verified by focusing through the cell.

Skill Box 4.6 / Complete Blood Count Procedure

Definition/Uses

Technique

Normals

Associated Conditions

Packed Cell Volume (PCV, hematocrit, Hct)

• Percentage of whole blood that is composed of RBCs

• Fill a capillary tube 2/3–3/4 full with whole blood and plug 1 end with a clay sealant. • Centrifuge and read results as a percentage. • Record the color and transparency of the plasma.

Canine • 37–55% Feline • 24–45% Plasma • Yellow and clear

• ↑ Polycythemia, dehydration, stress, neonates • ↓ Anemia, overhydration, weanlings

4

Total Protein Concentrationa (TP)

• Indicates oxygen transport capacity of the blood

• Break a spun capillary tube above the buffy coat level and put the plasma onto the face of the refractometer.

Canine • 5.4–7.6 g/dL Feline • 6.0–8.1 g/dL

• ↑ Dehydration • ↓ Overhydration

Hemoglobin Concentration (Hgb)

• Indicates how well the blood is transporting oxygen

• Follow manufacturer’s guidelines for machine’s use.

• 1/3 of the PCV

• ↑ (Falsely) lipemia, Heinz bodies • ↓ Hypochromic anemias

RBC Count

• Gives an accurate count of RBCs • Machine counters have shown to be more accurate than manual counting. • The main use of a RBC count is to calculate indices.

1. Prepare the sample (1 : 200 dilution) and hemacytometer (see Skill Box 4.7, page 108) 2. Find the grid at ×4, focus on the center square of the grid and then increase magnification to ×10, count the RBCs in the center square and each of the 4 corners using ×100. 3. Average the totals from grids of both stages and add 4 zeros. 4. Round to the nearest tenth place and put in scientific notation.

Canine • 5.5–8.5 × 106/μL Feline • 5–10 × 106/μL

• ↑ Polycythemia, dehydration • ↓ Anemia, overhydration

WBC Count (TWBC)

Gives an accurate count of total W.BCs

1. Prepare the sample (1 : 20 dilution) and hemacytometer. 2. Count the entire grid on ×10. 3. Average the totals from both grids. 4. (Averaged totals [AT] + 10% of AT) × 100 e.g., Grid #1 = 75 Grid #2 = 85 75 + 85 = 160/2 = 80 80 + 8 × 100 = 8,800 μL

Canine • 6,000–16,000 μL Feline • 5,000–19,000 μL

• ↑ Hemolysis, inflammation, hemorrhage, immune-mediated disease, infection, leukemia, necrosis, neoplasia, toxemia • ↓ Bone marrow disease, radiation, drug administration, retroviruses, myeloproliferative, lymphoproliferative diseases

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105

Skill Box 4.6 / Complete Blood Count (Continued) Procedure

Definition/Uses

Technique

Normals

Associated Conditions

Differential

• Indicates the number of specific WBCs found circulating in the blood • The TWBC count should roughly equal the differential totals

1. Examine a prepared blood smear using ×100. 2. Count up 100 WBCs (neutrophils [N], bands [B], lymphocytes [L], monocytes [M], eosinophils [E], and basophils) and classify according to type. 3. See Skill Box 4.8 Calculating a Differential, page 108.

Canine • N—3,600–11,500 • B— 0–300 • M—15–1,350 • L—1,000–4,800 • E—100–1,250 Feline • N—2,500–12,500 • B— 0–300 • M—0–850 • L—1,500–7,000 • E—0–1,500

• Variable dependent on type of cell(s) ↑ or ↓

Nucleated RBCs (nRBC) Color Plate 4.13

• Early release of immature RBCs • The corrected value should be calculated when >5 nRBCs are found and then used to calculate the differential.

1. While performing the differential, keep track of any nRBCs 2. Calculate a corrected TWBC count Corrected TWBC count = Observed TWBC count × 100 100 + nRBC

• N/A

• Anemia, lead poisoning, hemangiosarcoma

Platelet Estimate

• Indicates ability for adequate clotting

1. Examine a prepared blood smear using ×100 in which the RBCs are close but not touching, typically near the periphery of the slide. 2. Count 5 different fields and average. 3. Multiply by 15,000 and 18,000 to obtain a range. • When large areas of clumping are seen, assume adequate numbers of platelets.

Canine • 200,000– 500,000 μL Feline • 300,000– 800,000 μL

• ↑ Myeloproliferative disorder, megakaryocytic leukemia • ↓ B12, iron, or folic acid deficiency, drug toxicity, acute hemorrhage, radiation, viruses, uremia, aplastic anemia

4

Reticulocytes Not until a polychromatophilic erythrocyte is stained with Wright’s stain are they termed reticulocytes. These cells are large, anucleated cells containing RNA stained with a supravital stain (e.g., NMB). The RNA appears as blue intracellular granules. In canines, all reticulocytes are accounted for; however, in felines there are 2 types of reticulocytes and they should be counted and reported separately. Felines have aggregate reticulocytes and punctuate reticulocytes. Aggregate reticulocytes resemble canine reticulocytes and have distinct dark clumps of blue granules and would appear as polychromatophilic erythrocytes with Wright’s stain. Punctuate erythrocytes have individual scattered blue granules with no clumping and would appear as macrocytic mature red blood cells with Wright’s stain. When performing a reticulocyte count, only aggregate reticulocytes are counted as they are the best indicator of regenerative anemia. An ↑ in reticulocytes is expected 2–4 days after blood loss or destruction. A count >60,000 cells/μL indicates regenerative anemia and <60,000 cells/μL indicates a nonregenerative response. See Color Plates 4.13 and 4.17.

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Skill Box 4.6 / Complete Blood Count (Continued) Procedure

Definition/Uses

Technique

Normals

Associated Conditions

Reticulocyte Count

• Immature RBCs • Used to evaluate the bone marrow’s response to anemia • Perform along with a CBC when severe anemia is present. • PCV values: • Canine: ≤30% • Feline: ≤20%

1. Mix together an equal part of whole blood with NMB, and agitate, and let it sit for 10 minutes. 2. Prepare a blood smear. 3. Examine under ×100 by counting 1,000 RBCs while separately keeping track of the number of reticulocytes. 4. Divide the reticulocyte number by 1,000 and convert to a percentage. 5. Calculate the corrected reticulocyte number. Corrected retic. % = Observed retic. % × PCV Normal mean PCV for species

• <1%

• ↑ Regenerative anemias

RBC Indices Mean Corpuscular Volume (MCV)

• Indicates the size or volume of RBCs • Classifies anemias as normocytic, macrocytic, or microcytic

MCV (fl) =

Canine • 60–77 fL Feline • 39–55 fL

• ↑ Reticulocytosis, B12, folic acid deficiency • ↓ Iron deficiency

Mean Corpuscular Hemoglobin (MCH)

• The mean weight of Hgb in a RBC • Used as a lab check • ↑ MCH should see a ↑ MCV • ↓ MCH should see a ↓ MCV

MCH (PG) =

Canine • 19–24 PG Feline • 12–17 PG

• ↑ Hemolysis • ↓ Iron deficiency

Mean Corpuscular Hemoglobin Concentration (MCHC)

• Indicates the average hemoglobin concentration in each RBC • Classifies anemias as hypochromic or normochromic

MCHC (g dL) =

Canine • 32–36 g/dL Feline • 30–36 g/dL

↑ Hemolysis, lipemia, Heinz bodies ↓ Iron deficiency

PCV (%) × 10 RBC count × 106 μL

Hgb (g dL) × 10 RBC count × 106 μL

Hb (g dL) × 100 PCV (%)

4

a Score the capillary tube with the edge of slide just above the buffy coat to allow easy breaking. Using the unbroken end, tap onto the surface of the refractometer or blow air into the tube to expel the plasma.

CHAPTER 4 / LABORATORY

107

Skill Box 4.7 / Hemacytometer Use 1. Prepare the WBC or RBC sample, following manufacturer’s directions. 2. Shake the sample just before use to redistribute the cells. 3. Fill the stylette by squeezing the bottle and expelling any air bubbles. 4

4. Place the hemacytometer on the table, and place the coverslip on top. 5. While stabilizing the hemacytometer, place the stylet in the indented portion and gently squeeze just until the stage is filled • Overfilling of the stage will result in multilevels of RBCs and give falsely ↑ values. 6. Load up the other indented area as previously described.

Skill Box 4.8 / Calculating a Differential 1. Count up 100 WBCs and differentiate their type and record totals as %/μL. e.g., 45 neutrophils = 45%/μL = 0.45/μL 45 lymphocytes = 45%/μL = 0.45/μL 7 monocytes = 7%/μL = 0.07/μL 3 eosinophils = 3%/μL = 0.03/μL 0 basophils = 0 100 WBCs 2. Multiply each WBC type by the previously obtained TWBC count. e.g., TWBC count = 8,650 8,650 × 0.45 = 3893/μL neutrophils 8,650 × 0.45 = 3893/μL lymphocytes 8,650 × 0.07 = 606/μL monocytes 8,650 × 0.03 = 260/μL eosinophils 8,652/μL TWBC 3. The TWBC should roughly equal the TWBC count. e.g., TWBC (8,652) = TWBC count (8,650)

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Evaluation Once these tests have been performed, the blood is examined and evaluated on the basis of its morphology, inclusions, and presentation. While viewing in a monolayer area of the slide, the abnormality can be graded as the number per oil immersion field or the terms occasional and rare can be used. 1. Prepare a blood smear slide with stain or use the prepared slide from the differential. 2. Scan the slide, using low magnification. a. Platelet aggregation b. RBC rouleaux c. RBC agglutination 3. Examine the slide, using oil immersion magnification. a. RBC morphology i. Size ii. Shape iii. Color iv. Alterations b. WBC morphology i. Toxic changes ii. Nuclear degeneration iii. Cytoplasmic inclusions iv. Alterations c. Platelet i. Distribution ii. Alterations

RBC Alterations and Morphology The normal morphology of a canine RBC is a large, biconcave disc (7.5 μm) of uniform size with central pallor. A normal feline RBC is a slightly smaller biconcave disk (5 μm) with only slight central pallor. When observing the prepared slide for RBC morphology, the cells should be evaluated for alterations in size, shape, color, and inclusions.

Table 4.11 / RBC Alterations and Morphology (See figures in Color Plate 6–11) Alteration

Definition

Appearance

Associated Conditions

Agglutination

• Immunoglobulin related cell bridging

• Irregular, spherical aggregation or clumping of cells

• IMHA, mismatch blood transfusion

Rouleaux

• ↑ Concentration of plasma proteins (e.g., fibrinogen, immunoglobulins) which results in linear aggregations of erythrocytes

• Linear stacks or stack of coins

• Multiple myeloma, lymphoproliferative disorders, inflammatory conditions • Slight amount is a normal findings in canines and felines

Basophilic Stippling • Color Plate 4.13

• Residual RNA

• Very small, dark-blue inclusions on the surface of the RBC

• Anemia or lead poisoning

Distemper • Color Plate 4.14

• Virus antigen or viral inclusion bodies (identification variable)

• Variable sized round, oval, or irregular inclusions • Most often seen in polychromatophilic cells • Faint blue or magenta

• Canine distemper virus

Heinz Bodies • Color Plate 4.17

• Denatured hemoglobin caused by certain chemicals or oxidant drugs • Seen in up to 10% of normal feline RBCs

• Single, light-colored, rounded protrusions within the RBC membrane • Best seen using new methylene blue stain

• Lymphosarcoma, chronic renal failure, hyperthyroidism, diabetes mellitus, and oxidative toxins (e.g., onions, zinc, acetaminophen)

Howell-Jolly Bodies • Color Plate 4.13 • Color Plate 4.15 • Color Plate 4.30

• Basophilic nuclear remnants seen in young RBCs

• Dark blue to black spherical inclusions

• Splenic disorders

Hypochromasia • Color Plate 4.18

• ↓ Hemoglobin concentration • Can be confused with torocytes and immature polychromatophilic erythrocytes

• ↑ Area of central pallor • Doughnut appearance

• Iron deficiency • Often associated with anisocytosis in regenerative anemia

Polychromasia • Color Plate 4.16 • Color Plate 4.17 • Color Plate 4.20

• Immature erythrocytes that have been released early • When polychromatic erythrocytes are stained with a supravital stain (e.g., NMB), they are termed reticulocytes.

• Bluish or gray tint

• Iron deficiency, regenerative anemia

Microcytosis

• ↓ Cell volume

• RBCs smaller than normal

• Iron deficiency

Macrocytosis

• ↑ Cell volume • Immature RBCs, reticulocytes

• RBCs larger than normal

• Regenerative anemia

Arrangement

4

Inclusions

Morphology, Color

Morphology, Size

CHAPTER 4 / LABORATORY

109

Table 4.11 / RBC Alterations and Morphology (Continued) Alteration

Definition

Appearance

Associated Conditions

Anisocytosis • Color Plate 4.30

• Variation in cell volume • Multiple possibilities (e.g., early cell release or increased cell division of RBCs) • The number of cells showing variation and the degree of variation from the largest to the smallest cells should be noted

• Variation in cell size

• Liver disease, spleen disorders, regenerative anemia

Acanthocytes (spur cell) • Color Plate 4.20

• Caused by cholesterol concentration changes in the cell membrane

• Irregularly spiculated

• Severe liver disease, disseminated intravascular coagulation (DIC), hemangiosarcoma, hepatic lipidosis, lymphosarcoma, portosystemic shunts, and renal disease

Blister Cells (prekeratocytes) • Color Plate 4.18

• Fusion of inner cell membranes

• Blister or vacuole on the cell membrane

• Iron deficiency

Crenation

• pH changes associated with slowdrying blood films

• Notched or scalloped cell membrane

• Artifact • Mostly seen in cats

Dacrocytes

• Deformed during maturation process • Can be confused with smeared RBCs during smear preparation

• Tear shaped

• Myelofibrosis

Eccentrocytes (hemi-ghost cells)

• Fusion of opposing oxidized cell membranes

• Shifting of hemoglobin to 1 side, crescent shaped clear area outlined by a thin layer of membrane and lack of central pallor

• Oxidative injury

Echinocytes (burr cells)

• Mechanism unknown, possibly calcium or adenosine triphosphate (ATP) changes in vivo

• Evenly spaced, blunt to sharp projections of uniform shape and size • Scalloped edge

• Renal disease, lymphosarcoma, doxorubicin toxicity, electrolyte depletion, and snake bites

Keratocytes (bite or helmet cells) • Color Plate 4.18

• Blister cells (vacuolated cells) that enlarge and break open on 1 side of cell membrane

• Spiculated cells with 2 or more projections

• DIC, congestive heart failure, hemangiosarcoma, glomerulonephritis, and chronic doxorubicin toxicity

Leptocytes (codocytes, target cells) • Color Plate 4.19

• Characterized by ↑ membrane and ↓ hemoglobin levels

• Folded or resemble a target

• Nonregenerative anemia

4 Morphology, Shape

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SECTION THREE: DIAGNOSTIC SKILLS

Table 4.11 / RBC Alterations and Morphology (Continued) Alteration

Definition

Appearance

Associated Conditions

Nucleated RBCs (metarubricytes, normoblasts) • Color Plate 4.1 • Color Plate 4.13 • Color Plate 4.16

• Early release of RBCs still maintaining its • Dark purple nucleus in a normal-size nucleus RBC

• Regenerative anemia, splenic dysfunction, severe stress, hyperadrenocorticism, and corticosteroid treatment

Poikilocytosis

• Characteristic of ↑ RBC fragility

• Variation in shape

• Liver, kidney, spleen, and other vessel problems

Schistocyte (fragments, helmet cells) • Color Plate 4.20

• Shearing of the RBC by intravascular trauma

• Irregularly shaped fragments and sharp pointed projections

• DIC, vascular neoplasms, severe burns, and iron deficiency

Spherocyte • Color Plate 4.16

• ↓ Amount of cell membrane caused by partial phagocytosis by macrophages • Very difficult to distinguish in cats

• Small, dark, round RBCs with little or no central pallor

• Autoimmune hemolytic anemia (AIHA), transfusions, parasitic infections, zinc toxicity and snake venom toxicity

Stomatocytes (mouth cells)

• Multiple possibilities (e.g., leakage of sodium and potassium from the cell membrane)

• Cup shaped • Split-like center opening

• Liver disease, inherited disorders (e.g., Alaskan malamutes)

Torocytes

• Often confused with hypochromasia

• Bowl-shaped or “punched-out cell” • Thick outer ring of hemoglobin with a sharply defined central clear area

• Insignificant

Babesia spp. • Color Plate 4.21

• Rare protozoan, tick-transmitted disease of dogs

• Babesiosis (acute intravascular and extravascular • Large, teardrop- or ring-shaped hemolysis with hemoglobinuria) intercellular structures, often seen in pairs • Size: 1.5–3.0 μm

Cytauxzoon felis • Color Plate 4.22

• Rare protozoan, tick-transmitted disease of cats

• Small, irregular rings within RBCs, lymphocytes, or macrophages • Size: 0.5–2.0 μm

• Hemolytic anemia, icterus, depression, and fever

Mycoplasma haemocanis

• Rare rickettsial disease affecting dogs

• Chain of small cocci or rods that stretch across the surface of an RBC • Chains may branch • Size: 0.3–3.0 μm

• Splenectomized or immunocompromised dogs

Mycoplasma haemofelis Color Plate 4.15

• Common rickettsial disease of cats • Parasite is cyclic, and multiple slides may need to be evaluated for a diagnosis. • Parasite rapidly disappears with antibiotic treatment (e.g., tetracyclines).

• Nonrefractile cocci, rod- or ring-like structures on the periphery of RBCs • Stain dark purple • Size: 0.5–1.0 μm

• Immunocompromised cats, feline hemobartonellosis, or feline infectious anemia

4

Parasites

CHAPTER 4 / LABORATORY

111

WBC Morphology The job of WBCs is to defend the body against foreign organisms, conducting their business in the tissues themselves. They are typically nonfunctional in

the circulatory system. WBC morphology is significantly different between each type of cell. The frequency that they appear in the body is the order listed below.

Table 4.12 / WBC Morphology (See figures in Color Plate 6–11)

4

WBC

Definition

Appearance (stained)

Associated Conditions

Neutrophils (Polys, Segs) • Color Plate • Color Plate • Color Plate • Color Plate

• First line of defense against infection • Highly motile and phagocytic • Replaced in the body 2.5 times per day

• Convoluted and segmented nucleus • Clear to light pink cytoplasm with diffuse granules • Coarse and clumped chromatin

• ↑ Fear, exercise, stress, or inflammation • ↓ Severe infections, infectious agents causing decreased bone marrow production, chemical toxicity, and genetic disorders

Bands • Color Plate 4.23

• Immature neutrophils • Hyposegmented nucleus with the constriction being <1/2 the width of the nucleus • Left shift is an ↑ in immature neutrophils

• Nucleus is horseshoe shaped with large round ends

• ↑ Inflammation, bacterial infection, and neoplasia

Lymphocytes • Color Plate 4.24 • Color Plate 4.30

• Immunity and antibody production • Virus and tumor defense

• Large, round, slightly indented, dark nucleus • Round cell with a small amount of blue cytoplasm • Large, pink cytoplasmic granules

• ↑ Fear, excitement, chronic infections, leukemias, and lymphosarcoma • ↓ Corticosteroids, immunodeficiency diseases, loss of lymph, and impaired lymphopoiesis

Monocytes • Color Plate 4.25 • Color Plate 4.26

• Highly phagocytic; digesting particulate and cellular debris • Antiviral and antitumor qualities • Become macrophages once in extravascular space

• Large, elongated, lobulated, or indented nucleus • Bluish-gray cytoplasm • Large cell with lacy appearance caused by vacuoles • Pink dustlike inclusions • Diffuse nuclear chromatin • Blunt, agranular, light blue cytoplasmic pseudopods

• ↑ Corticosteroids, stress, or severe infections and hemorrhages

Eosinophils • Color Plate 4.27 • Color Plate 4.29 • Color Plate 4.30

• Ingest products of antibody/antigen reactions • Replaced once daily

Canine • Clear cytoplasm with small to large, dull orange granules partially filling cell Feline • Pale cytoplasm with small, dull orange granules completely filling cell

• ↑ IgE stimulation, parasitic infections and allergies • ↓ Corticosteroids

Basophils • Color Plate 4.28 • Color Plate 4.29

• Their function is still unclear, but related to immunity • Rarely seen, possibly because of rapid degranulation

Canine • Dark purple granules partially filling cell • Highly segmented nucleus • Gray-blue cytoplasmic vacuoles Feline • Violet cytoplasm with oval, nonstaining granules • Highly segmented nucleus

• ↓ Hyperlipemia, chronic IgE stimulation and allergies

112

4.15 4.23 4.29 4.30

SECTION THREE: DIAGNOSTIC SKILLS

Table 4.13 / WBC Alterations

Neutrophil toxic change refers to morphologic changes due to altered bone marrow production. The neutrophils’ function is not altered, and they function normally. During an inflammatory response, the bone marrow releases neutrophils at an accelerated rate causing morphology changes such as Döhle bodies, cytoplasmic basophilia, and vacuolation. Reported by an index of 1+, 2+, etc. See Color Plates 4.32 and 4.33. Alteration

Definition

Appearance

Associated Conditions

Distemper

• Virus

• Variable sized round, oval, or irregular cytoplasmic and nuclear inclusions • Most often seen in polychromatophilic cells • Faint blue or magenta

• Distemper virus

Döhle Bodies • Color Plate 4.32 • Color Plate 4.33

• Retained rough endoplasmic reticulum • Seen with ↓ time in the marrow for maturation

• Bluish–gray, angular cytoplasmic inclusions • Typically found at the periphery of the cell • Size: 0.5–2.0 μm

• Severe toxemia, inflammation, and infection

Chediak-Higashi Syndrome

• Autosomal recessive inherited disorder • Fusion of preexisting granules • Persians are most commonly affected

• 1–4 large (2.0 μm), fused lightly pink or eosinophilic cytoplasmic lysosomes in neutrophils • Band appearing eosinophils

• Chediak-Higashi syndrome

Cytoplasmic Basophilia • Color Plate 4.32 • Color Plate 4.33

• Persistent ribosomes

• Varying degree of solid to patchy light blue to blue-purple cytoplasm

• Severe toxemia, inflammation, and infection

Cytoplasmic Vacuolation • Color Plate 4.33

• Disruption in bone marrow production, resulting in a loss of granule and membrane integrity

• Foamy, bubble-like, nonstaining circles

• Systemic toxicity

Mucopolysaccharidoses

• Deficiency of lysosomal enzymes needed for the degradation of glycoaminoglycans

• Dark purple or magenta granules in neutrophils • Granules and vacuoles in lymphocytes

• Mucopolysaccharidoses, lysosomal storage disorders

Nuclear Hypersegmentation

• Prolonged circulating life

• ≥5 nuclear lobes

• Aged neutrophils, prolonged storage of blood

Nuclear Hyposegmentation

• Early release of bands and immature neutrophils

• Unsegmented nucleus

• Steroid use, inflammatory response if intense/severe

Pelger-Huët anomaly

• Seen in heterozygotes for Pelger-Huët anomaly

• Hyposegmented mature neutrophils with a coarse chromatin pattern without inflammation present

• Pelger-Huët anomaly

Pyknosis

• Result of improper anticoagulant • Effect on nucleus

• Condensed, lysed or damaged nucleus

• Insignificant

Inclusions

4

Morphology

CHAPTER 4 / LABORATORY

113

Table 4.13 / WBC Alterations (Continued)

4

Alteration

Definition

Appearance

Associated Conditions

Reactive Lymphocyte (Immunocytes) • Color Plate 4.31

• Immune-stimulated T- and B-cells

• Cytoplasm and basophilia and a larger, more convoluted nucleus

• Antigenic stimulation (e.g., canine ehrlichiosis)

Vacuolated Lymphocytes

• Accumulation of storage products (e.g., proteins, carbohydrates, lipids)

• Cytoplasmic vacuoles

• Acquired lysosomal storage disorder, prolonged storage of blood

Cytauxzoon felis

• Rare protozoan, tick-transmitted disease of cats

• Small, irregular rings within RBCs, lymphocytes, or macrophages • Size: 0.5–2.0 μm

• Hemolytic anemia, icterus, depression, and fever

Ehrlichia canis

• Rickettsia, tick-transmitted disease of dogs

• Large granular lymphocytes • ↑ Cytoplasm and cell size • Variable sized pink cytoplasmic granules typically clustered next to the nucleus (difficult to find)

• Ehrlichiosis

Parasites

Table 4.14 / WBC Left Shift

An increased number of circulating immature neutrophils indicates a left shift. Bands are the most common immature neutrophil identified; however, metamyelocytes and myelocytes can also be seen in more severe cases. Appearance Left Shift

• ↑ Immature neutrophils • >300 μL/blood

Regenerative Left Shift

• • • •

Degenerative Left Shift

• Neutropenia or slight neutrophilia • Mature cells < immature cells • Leukopenia

Transitional Left Shift

• Moderate to marked neutrophilia • Mature cells < immature cells

Right Shift

• Nuclear hypersegmentation

Stress Leukogram (Corticosteroid Leukogram)

• • • •

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SECTION THREE: DIAGNOSTIC SKILLS

Neutrophilia Mature cells > immature cells Lymphopenia Monocytosis

Mature neutrophilia Lymphopenia Eosinopenia +/− Monocytosis

Platelet Morphology

1. Venipuncture should be atraumatic while using the largest vein possible.

Platelets absorb and carry plasma factors needed to form fibrin to facilitate hemostasis. These thrombocytes vary in size and shape and are nonnucleated with pale blue to lavender granules. They are often seen in clumps at the periphery or feathered edge of a prepared slide. See color plates 4.15, 4.17, and 4.30.

2. Drawn blood should come into contact with the tube additive as soon as possible. 3. The following tubes will give invalid results and should not be used: LTT, GRNTT, SST. 4. Spun samples that are hemolyzed or have visible clots should be redrawn.

4

Table 4.15 / Platelet Alterations Alteration

Definition

Appearance

Associated Conditions

Megathrombocytes (Stress platelets, shift platelets, or giant platelets) • Color Plate 4.31

• Seen in felines, contributes to not being able to use an electronic counter

• Larger than an RBC

• Bone marrow disorders, myelo proliferative disorders

Table 4.16 / Coagulation Screening

Specific coagulation tests are chosen based on which factors they are able to evaluate. Coagulation Factor

ACT

APTT

PIVKA

PT

TT

Extrinsic Pathway

Coagulation Tests Hemostasis is the normal arrest of bleeding and abnormalities of this process can be seen as excessive bleeding (hemorrhage) or excessive hemostasis (intravascular thrombosis). The coagulation process is a sequence of events divided into 3 pathways; intrinsic, extrinsic, and common. Each pathway consists of several coagulation factors that contribute to the entire hemostasis process. A deficiency or abnormality in any 1 or combination of factors can alter the entire process leading to a coagulopathy. Coagulation tests are performed in patients exhibiting signs of questionable clotting abilities. They are able to distinguish between a coagulation problem and a patient with damaged or diseased blood vessels. These tests or a combination of tests can aid in a diagnosis (e.g., von Willebrand disease, DIC) or as monitoring to a hereditary condition or current condition. Blood drawn for coagulation tests must be collected and handled following very specific guidelines to obtain proper results. Activation of the clotting pathway will give erroneous results. Some tips to remember are:

III

X

VII

X

X

Intrinsic Pathway VIII

X

X

IX

X

X

XI

X

X

XII

X

X

I (Fibrinogn)

X

X

II (Prothrombin)

X

X

V

X

X

X

X

X

X

Common Pathway X X

X

X X

X

X

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115

Skill Box 4.9 / Coagulation Tests Test

Definition

Procedure

Normals

Activated Clotting Time (ACT)

• Test of intrinsic clotting mechanism • Less sensitive than APTT • Clot formation may be inhibited by administration of salicylates, NSAIDs, anticoagulants, antibiotics, barbiturates.

1. Warm syringe and tube containing diatomaceous earth to 98° F (37° C).a 2. Inject 2 mL freshly drawn whole blood into tube and invert 5 times to mix. 3. Begin the clock with the injection of blood into the tube and incubate in a warm water bath for 1 minute. 4. Observe at 5-second intervals for the first sign of clotting. • Place the tube back in incubation between each 5-second check.

Canine • 60–120 seconds Feline • 60–75 seconds • May be slightly prolonged with thrombocytopenia

Buccal Mucosal Bleeding Time (BMBT)

• Making a standard wound and noting the time to the cessation of bleeding. • Some NSAIDs, analgesics and sedatives may alter the results. • Evaluates platelet dysfunction and severe von Willebrand disease

1. Make a deep puncture at a site with no hair (e.g., buccal, gingiva, nose). 2. Begin timing when blood appears. 3. Remove the blood with filter paper at 30second intervals. 4. Stop timing when there is no more blood. • Do not touch the skin with the filter paper.

Canine/Feline • 1–5 minutes

Toenail Bleeding Time (TBT)

• Evaluates platelet dysfunction, severe von Willebrand disease, hemorrhagic phase of DIC, and coagulation factor deficiencies

1. Clip a toenail back past the quick to cause bleeding. 2. Keeping the animal undisturbed, monitor for the bleeding to cease.

Canine/Feline • <5 minutes

Platelet Estimate

• Estimation of platelet number

1. Examine a prepared blood smear, using ×100 on a place where the RBCs are close but not touching near the periphery. 2. Examine at least 5 fields to ensure accurate results.

Canine • 8–29/×100 field Feline • 10–29/×100 field

Clot Retraction Test

• Evaluation of platelet number and function and intrinsic and extrinsic pathways.

1. Draw a blood sample into a plain sterile tube and incubate at 37° C. 2. Exam the tube at 60 minutes where a clot should be evident. 3. Examine the tube at 4 hours to find a retracted clot. 4. Examine the tube at 24 hours to find a markedly compact clot.

• 60 minutes: clot evident • 4 hours: clot retracted • 24 hours: clot markedly compact

Quick Assessment Tests

4

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SECTION THREE: DIAGNOSTIC SKILLS

Skill Box 4.9 / Coagulation Tests (Continued) Test

Definition

Procedure

Normals

• Test of intrinsic clotting mechanism and common coagulation pathways • Measure the time in seconds for fibrin clot formation. • Proper dilution is crucial to the accuracy of this test.

1. Draw a fresh blood sample to fill a BTT. 2. Gently invert sample 6–10 times to activate anticoagulant. 3. Refrigerate if testing is <24 hours or centrifuge sample, pipette off plasma, and freeze in a plastic tube.

Canine • 8–13 seconds Feline • 13–30 seconds

Fibrin Split Product (FSP) or Fibrin Degradation Product (FDP)

• Measures the presence of products that result from the action of plasmin on fibrin and fibrinogen • Proper dilution is crucial to the accuracy of this test. • Aids in DIC diagnosis

1. Draw a fresh blood sample to fill an FDP tube (2 mL). 2. Gently invert sample 6–10 times. • Clot formation should occur shortly after blood draw.

Canine/Feline • <10 mg/mL

Fibrinogen

• Quantitative measure of plasma fibrinogen

1. Draw a fresh blood sample to fill an LTT. 2. Gently invert sample 6–10 times to activate anticoagulant.

Canine • 100–250 mg/dL Feline • 100–350 mg/dL

Protein C Activity Assay

• Measures the percentage of protein C • Aids in the diagnosis of thrombotic disorders and hepatic disease

1. Draw a fresh blood sample, using a needle (vacutainer preferred), into a 2-mL BTT, or use a syringe containing citrate (1 part citrate to 9 parts blood). • Do not use a dry syringe and then transfer blood into a BTT. 2. Centrifuge blood and gently pipette off plasma into a plastic container and freeze.

Canine • 75–135% Feline • 65–120%

Protein Induced by Vitamin K Antagonism/Absence (PIVKA Test)

• Detects any coagulation factor deficiency of extrinsic clotting mechanism and common coagulation pathways

1. Draw a fresh blood sample to fill a BTT. 2. Gently invert sample 6–10 times to activate anticoagulant. 3. Centrifuge sample, pipette off plasma, and freeze in a plastic tube.

Canine • <25 seconds

Prothrombin Time (PT)

• Test of extrinsic clotting mechanism and common coagulation pathways • Measures the time in seconds for fibrin clot formation • Proper dilution is crucial to the accuracy of this test. • Used for vitamin K antagonist poisons

1. Draw a fresh blood sample to fill a BTT. 2. Gently invert sample 6–10 times to activate anticoagulant. 3. Refrigerate if testing is <24 hours or centrifuge sample, pipette off plasma, and freeze in a plastic tube.

Canine • 5–8 seconds Feline • 8–11 seconds

Definitive Tests Activated Partial Thromboplastin Time (APTT)

CHAPTER 4 / LABORATORY

4

117

Skill Box 4.9 / Coagulation Tests (Continued) Test

Definition

Procedure

Normals

Thrombin Time (TT)

• Test abnormalities of the conversion of fibrinogen to fibrin • Measures the amount of time for a fibrin clot formation in citrated plasma after the addition of thrombin • Normal values with rodenticide poisonings

1. Draw a fresh blood sample to fill a BTT. 2. Gently invert sample 6–10 times to activate anticoagulant. 3. Refrigerate if testing is <24 hours or centrifuge sample, pipette off plasma, and freeze in a plastic tube.

Canine/Feline • 10–12 seconds

von Willebrand Factor Assay (vWF)

• Measurement of vWF antigen • Proper dilution is crucial to the accuracy of this test. • Do not test during pregnancy, estrus, lactation.

• Draw sample before beginning therapy (e.g., plasma, cryoprecipitate) or wait 48 hours post therapy. 1. Draw a fresh blood sample, using a vacutainer needle, into a 2-mL BTT, or use a syringe containing citrate (1 part citrate to 9 parts blood). • Do not use a dry syringe and then transfer blood into a BTT. 2. Centrifuge blood and gently pipette off plasma into a plastic container. • Within 30 minutes, the sample should be centrifuged, transferred into a plastic tube, and frozen.

• Variable, dependent on bleeding time and vWF antigen percentage

4

a

118

Place the tube against your body (e.g., armpit or hand) for easy incubation.

SECTION THREE: DIAGNOSTIC SKILLS

Blood Transfusions

Skill Box 4.10 / Crossmatching Crossmatching determines the compatibility between donor and recipient blood by washing erythrocytes and incubating them with plasma. This procedure will identify incompatibilities that are not identified on blood typing since blood typing only identifies the most common types. However, crossmatching will not pick up low titer antibodies or WBC antigens and not identify incompatibilities to DEA 1 blood types unless previous sensitization (e.g., prior transfusion history) has occurred. Crossmatching is not a substitute for blood typing; both procedures must be performed on every patient (especially feline). Crossmatch

Use

Procedure

Results

Major

• Comparing donor erythrocytes to recipient serum • Checking for preformed antibodies in the recipient serum against RBCs from the donor

Positive • Any hemolysis or agglutination voids any chance of transfusions with this donor. • Agglutination appears as grape-like clusters.

Minor

• Comparing recipient erythrocytes to donor serum • Checking for preformed antibodies in the donor serum that could hemolyse recipient RBCs

1. Collect 1 mL of donor blood and 1 mL of recipient blood and place them each in a separate purple top tube (EDTA) or green top tube (heparin). Spin each tube for 10 minutes to separate plasma. Remove and save the plasma from each in clean glass or plastic tubes. 2. Wash the RBCs by taking 0.2 mL of RBCs and diluting in 5 mL of 0.9% saline. Spin this for 1 minute, remove the supernatant, and repeat the procedure 2 more times with the pelleted RBCs. 3. Prepare 3 tubes by labeling them as Major, Minor, and Recipient Control. To each tube, add 2 drops of plasma and 2 drops of blood to each as follows: • Major crossmatch: recipient plasma + donor cells • Minor crossmatch: donor plasma + recipient cells • Recipient control: recipient plasma + recipient cells 4. Let the tubes sit at room temperature for 15–30 minutes and then centrifuge for 15 seconds. 5. Check the supernatant for hemolysis and then gently resuspend the pellet by tapping the tube to check for RBC agglutination. Agglutination or hemolysis of the control indicates immune-mediated disease. 6. If agglutination is not observed, transfer a small amount to a slide and examine for microscopic agglutination.

4

Positive • Severe hemolysis or agglutination voids transfusion with this donor. • If the donated plasma with slight hemolysis or agglutination is to contribute substantially to the recipient’s plasma volume, the plasma should be removed from the whole blood and packed RBCs should be reconstituted with sterile saline.

CHAPTER 4 / LABORATORY

119

Skill Box 4.11 / Blood Typing Procedure

Results

Canine

Follow the manufacturer’s directions • Add the diluent to each well to rehydrate the lyophilized material. Add 1 drop of the controls and purple top blood sample to appropriate wells. Mix each well and then rock the test card. Prop the card up at a 10° angle to allow the blood to fall to the bottom of the well. Note the wells where gross agglutination has occurred.

• If the patient shows gross agglutination in the well marked “Patient Test” and there is no autoagglutination, the patient is DEA 1.1 positive. If no agglutination is visible in the well marked “Patient Test,” the patient is DEA 1.1 negative. • If the patient is very anemic, the pattern of agglutination may be in the form of discrete, small aggregations, each like the head of a large pin, rather than gross agglutination. • Any fine, granular appearance developing after 2 minutes should be disregarded in determining results.

Feline

Follow the manufacturer’s directions • Add the diluent to each well to rehydrate the lyophilized material. Add 1 drop of the controls and purple top blood sample to appropriate wells. Mix each well and then rock the test card. Prop the card up at a 10% angle to allow the blood to fall to the bottom of the well. Note the wells where gross agglutination has occurred.

• If the assay was run correctly, visible agglutination should have occurred in at least 1 of the wells marked “Patient Test.” • If the patient sample shows agglutination in the well marked “Type A,” the cat tested has blood group A. If the patient sample shows agglutination in the well marked “Type B,” the cat tested has blood group B. If the patient sample shows agglutination in both patient wells, the cat tested has blood group AB. • If the patient is very anemic, the pattern of agglutination may be in the form of discrete, small aggregations, each like the head of a large pin, rather than gross agglutination. • Any fine, granular appearance developing after 2 minutes should be disregarded in determining results.

4

IMMUNOLOGY AND SEROLOGY TESTS Table 4.17 / Immunology and Serology Tests

Immunology and serology tests are specialized laboratory tests used to obtain information regarding the functioning status of the immune system and the diagnostic identification of antibodies in the serum, respectively. They can be valuable tools in the diagnostics of infectious diseases and autoimmune diseases when used in conjunction with other diagnostics. Due to the complexity of these tests, reference laboratories are required for their processing. Each laboratory has varying requirements for sample submission and should be referred to for more information. See Blood Chemistries for Blood Collection, Handling, Storage, and Transport Tips, page 74. Test

Technique

Associated Conditions

Coombs’ Test (Direct Antiglobulin Test)

A species-specific Coombs’ reagent is added to the blood. RBCs that are coated with antibodies will cause agglutination with the added reagent.

• Autoimmune hemolytic anemia (AIHA)

Enzyme-Linked Immunosorbent Assay (ELISA)

A tray with antibody coated wells is filled with the sample. If any antigen is present, it will bind with the antibody in the coated wells. A second enzyme-tagged antibody is added and binds to the antibody–antigen complex. A substrate that reacts with the enzyme is then added and results in a color change if antigen is present. The color change is proportional to the amount of antigen in the sample. The antigen may be actual viral/bacterial material (e.g., FeLV) or the host’s antibody vs. the pathogen (e.g., FIV).

• Heartworm, canine parvovirus, FIV, FIP, FeLV, toxoplasmosis, progesterone, atopy, nonregenerative anemia, allergies, and Lyme disease

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SECTION THREE: DIAGNOSTIC SKILLS

Table 4.17 / Immunology and Serology Tests (Continued) Test

Technique

Associated Conditions

Immunodiffusion

Viral antigen and an antibody are placed into separate wells in agar. They diffuse through the agar and form a visible band of precipitation if any viral antigen is present.

• Viral and fungal pathogens

Immunofluorescence Assay (IFA) Direct IFA

An antibody for a specific virus is tagged with a fluorescent dye and combined with the sample. If the specific virus is present, the antibody will bind and appear fluorescent during microscopic examination.

• Ehrlichiosis and Rocky Mountain spotted fever

Indirect IFA

An antiviral antibody (immunoglobulin) that was produced in an animal (e.g., rabbit) and a fluorescent tagged antirabbit immunoglobulin are combined with a sample. The second antibody combines with the first antibody, which binds to any viral antigen present in the sample. The antibody-antibody-antigen complex will fluoresce during microscopic examination.

• Cryptosporidium, FIV, Giardia, and systemic lupus erythematosus

Immunoperoxidase Test (PAP)

A specific antibody is bound to the cell or tissue sample. The detection of specific antibody can be done through 3 different methods, all consisting of tagging the antibody and eventually generating a colored product.

• CDV, distemper, FeLV, FIP, Neospora, Toxoplasma

Intradermal Tests

Allergenic extracts are injected intradermal and observed for changes. A wheal formation indicates the presence of antibodies and an allergic reaction.

• Allergies; flea allergy

Latex Agglutination

Small, spherical antibody (or antigen)–coated latex particles are suspended in water. The sample is added, and any antibody–antigen complex will undergo agglutination. The water will be milky or contain clumps of latex particles.

• Canine rheumatoid factor, brucellosis, and DIC antigen complexes that form will cause agglutination.

Polymerase Chain Reaction (PCR)

A specific nucleic acid primer reacts with a portion of the genome from the microorganism in question. The combination is amplified to produce many fragments of the DNA sequence. Electrophoresis is then used to detect the combination and to measure its size and migration pattern. • Often used to confirm results of other tests

• Herpesvirus, FeLV, FIV, coronavirus, Bartonella, Ehrlichia, etc.

Radioimmunoassay

An antibody for a specific virus or antigen is tagged with a radioactive element (e.g., iodine) and combined with the sample. A gamma counter is used to identify the antibody–antigen complex.

• Thyroid diseases

Serum Antinuclear Antibody (ANA)

Serum is serially diluted and added to a prepared slide with 10 areas of monolayer cell lines. If antinuclear antibodies are present, they bind to the nucleus and can be detected through immunofluorescence or immunoperoxidase techniques.

• Glomerulonephritis, immune mediated thrombocytopenia, polyarthritis, polymyositis, systemic lupus erythematosus

CHAPTER 4 / LABORATORY

4

121

Table 4.17 / Immunology and Serology Tests (Continued) Test

Technique

Associated Conditions

Serum Rheumatoid Factor

Latex beads are coated with an antigen which will bind to the rheumatoid factor antibody found in serum or synovial fluid of affected animals

• Polyarthritis of erosive/lytic type

Western Blot (Immunoblot)

Antigens are separated by electrophoresis and blotted to nitrocellulose sheets. The sheets are incubated with labeled antibodies and then observed for bound antibodies by using enzymatic or radioactive methods. • Used to confirm ELISA results

• FIV

4

MICROBIOLOGY A small animal laboratory should only be responsible for presumptive identification of bacteria. Further tests for a definitive diagnosis should be sent to a referral laboratory, where they have access to a greater number of techniques and equipment. Skill Box 4.12 outlines basic guidelines for collection of the sample followed through to the preliminary evaluation and interpretation of bacterial growth. Books dedicated to the subject of microbiology should be consulted for further discussion of alternative tests and techniques.

122

SECTION THREE: DIAGNOSTIC SKILLS

Microbiology Collection, Handling, Storage, and Transport Tips Collection • Collect sample aseptically. • Collect an adequate amount of the samples to allow for complete examination. • Samples should be attained before starting antibiotic therapy.

Skill Box 4.12 / Collection Techniques Site

Collection

Abortion

• Entire fetus or multiple specimens from a range of body parts should be obtained as soon as possible after the animal has died.

Abscess/Wound

• Unruptured: sterile syringe with wide-bore needle • Ruptured: swab near the edge of the wound and take scrapings from the inside wall of the abscess.

Anaerobic bacteria

• Sterile syringe with fine-gauge needle • Expel all air out of syringe before obtaining sample.

Blood

• 5–10 mL of blood from at least 2 different sites and immediately placed in separate blood culture bottles. Collect multiple samples throughout the day.

Ear

• Swabs of both ears canals and middle ear if needed

Eye

• Corneal scrapings, swab of the conjunctival sac, or swab of lacrimal secretions

Fecal

• 1 g freshly voided or rectal examination–obtained feces • Clean anus before collection to avoid contamination with anal skin microflora.

Genital

• Swab of vulvar mucosa

Leptospirosis

• 20 mL of midstream urine

Urine

• 5 mL urine via a catheter or cystocentesis

4

Note: See Cytology, Skill Box 4.3, page 88, and Urinalysis, page 150, and Skill Box 12.8, page 434, and Skill Box 12.10, page 435, sections for specimen collection techniques.

Handling • Samples should be handled carefully to avoid human contamination. • Separate multiple samples to avoid cross contamination. • Maintain a clean environment in which the laboratory tests are run. • Wood-shafted and cotton-tipped swabs should not be used with samples suspected of Chlamydia.

Storage • Swabbed samples need to be placed in a transport media if they are not immediately inoculated. • Agar plates must be stored inverted to prevent condensation buildup on the surface of the agar.

• Sample should be clearly marked with patient’s name, number, origin of the sample, time of collection and whether it was refrigerated.

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Table 4.18 / Specimen Storage

4

Test

Specimen

Storage

Acid-Fast Stain

Tissue

• Red top tube

Slides

• Slide holder

Anaerobic Bacteria

Fluid

• Sterile syringe with fine-gauge needle in a rubber stopper secured with tape • Culturette swab

Blood

Blood (5–10 mL)

• Blood culture bottle (commercially prepared)

Chlamydia

Tissue or dacron swab

• Chlamydia transport media

Culture and Sensitivity (bacterial)

Swab

• Culturette swab or Transwab

Fluid

• Red top tube

Tissue

• Enteric transport media or red top tube

Fecal Culture

Feces

• • • •

Fungal culture

Hair, scrapings or swab (yeast only)

• Red top tube • Culturette swab • Transwab

Fluid

• Screw-cap tube

Slides

• Slide holder

Swab

• Culturette swab • Transwab

Fluid or tissue

• Red top tube

Swab

• Culturette swab • Transwab

Fluid

• Red top tube

Tissue

• Enteric transport medium • Red top tube

Plate with growth

• Culture plate

KOH Preparation

Scrapings or clipped hair or nails

• Red top tube

Mycoplasma

Fluid and tissue

• Mycoplasma transport media • Culturette swab • Note: Mycoplasma may adhere to swabs, giving negative results

Sensitivity Only

Plate with growth

• Culture plate

Urine

Fluid

• Culture needs to be set up within 2 hours to avoid overgrowth of insignificant bacteria or refrigerated for no longer than 18–24 hours

Gram Stain

Identification Only

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Culturette swab Enteric transport media Red top tube Clean, dry container

Transport • Tape the lids and caps of inoculated tubes and plates before shipment.

• Empty the water that has accumulated on the lid to avoid it dropping onto the agar plate and mixing the colonies of bacteria.

• Tissue submitted for fungal cultures should be frozen and marked “Caution” because of its zoonotic potential.

4 Table 4.19 / Most Commonly Used Culture Media

Numerous types of culture media are available; however, most veterinary clinics use only a few. The more extensive cultures are sent to reference laboratories for growth and interpretation.

a

Medium

Preparation

Uses

Interpretations

Blood Agar

• Trypticase soy agar • Sheep’s blood

• Enriched media that supports the growth of most bacteria

• Observe for growth, rate of growth, morphology, and hemolytic patterns: • Gamma: no lysis or color change • Alpha: incomplete lysis of RBCs, greenish halo around the bacterial growth • Beta: lysis of RBCs, clear halo around bacterial growth

Brain–Heart Infusion Broth

• Calf’s brain • Beef’s heart • Dextrose

• Enrichment media to increase the number of organisms

• Subcultures are made onto agar plates after incubation of 24 hours

Dermatophyte Test Medium

• • • •

• Detection of Microsporum canis and Microsporum gypseum

• Observable growth with a simultaneous red color change in 14–21 days

MacConkey Agar

• Crystal violet • Bile acids • pH indicator

• Selects for gram-negative and Enterobacteriaceae • Helps differentiate bacteria

• Pink to red colonies: lactose fermenters • Colorless to light yellow colonies: nonlactose fermenters

Thioglycollate Brotha

• Thioglycollic acid • Yeast extract • Dextrose

• Supports growth of anaerobic and facultative anaerobic bacteria

• Turbid or streaks if turbidity is not disturbed

Sabouraud’s dextrose agar Antibiotic Cycloheximide Phenol red

Thioglycollate broth should not be used as the only source of collection media.

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Skill Box 4.13 / Culture Media Inoculation and Incubation

General Points for Proper Technique • Keep culture plates closed unless inoculating or transferring specimens. • Do not set down the tube cap of medium to avoid contamination. • Flame the neck of the tube before and after transferring specimens. 4

b. Stab only: stab the wire through the agar and then slowly withdraw it along the same stab path. c. Butt and Slant: combine the above 2 methods, starting with the stab method and finishing with the slant method. 4. Remove the wire and reflame.

• When flaming the inoculation loop or wire, place the end closest to the handle in the hottest portion of the flame, the blue portion, and then move toward the loop to prevent splattering.

Broth Inoculation

• When transferring the sample to the agar, use a gentle touch to avoid tearing the surface of the agar.

2. Dip the wire into the specimen to be cultured.

Plate Inoculation 1. Mentally divide the agar plate into 4 quadrants. 2. Flame and cool the inoculation loop.

1. Flame and cool the inoculation loop or wire. 3. Insert the loop or wire into the broth just below the surface and touch the side of the tube. 4. Remove the loop or wire and reflame. Tip: Work with 2 inoculation loops; one can be cooling while the other is in use.

3. Dip the loop into the specimen to be cultured. 4. Streak the specimen in quadrant A.

Incubation of Cultures

5. Repeat steps 2–4 while slightly overlapping the previous quadrant and then moving around to each quadrant. Be sure to only overlap the previous quadrant’s streaks 1–2 times to prevent excessive numbers of bacteria in 1 area. Quadrant D is expected to grow isolated colonies.

• Maintain incubator temperature at 98.6° F and humidity of 70%.

7. Remove the loop and reflame.

Slant Inoculation 1. Flame and cool the inoculation wire. 2. Dip the wire into the specimen to be cultured. 3. Types of slant inoculations: a. Slant only: make a “S” shape across the slant with the tip of the inoculation wire.

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• Plates should be placed upside down to prevent the accumulation of condensation on the surface of the agar plate. • Tube media screw caps should be left loose during incubation. • Cultures should be incubated for 48 hours and checked after 24 hours. • To ↑ the level of carbon dioxide, place the plates upside down in a glass jar with a candle on top. Light the candle and place a tightly fitting lid on top. Allow the candle to burn itself out, which will decrease the amount of oxygen and increase the amount of carbon dioxide. This does not create an anaerobic environment. • Place a bowl of water in the bottom of the incubator to maintain a high humidity.

Evaluation of Culture Growth

c. Acid-fast stain d. Negative stain

1. Identify the source of the sample.

5. Differentiation tests

2. Growth Significant

Not Significant

• Only 1–2 types of bacterial growth • >3 Types of scant bacterial growth • Circular colonies with clear edges, • Large, irregular, and granular smooth, convex, or rounded colonies and spreading edges • Opaque to gray

• Heavily pigmented

3. Changes to the media a. Hemolytic pattern b. Color change c. Odor 4. Microscopic evaluation

a. Catalase test i. Differentiates between catalase-positive (e.g., staphylococci) and catalase-negative (e.g., streptococci, enterococci) bacteria ii. Positive test: formation of bubbles b. Oxidase test i. Differentiates between oxidase-positive (e.g., Bordatella bronchiseptica, Pseudomonas aeruginosa) and oxidase-negative (e.g., enterobacter species, escherichia species) bacteria ii. Positive test: purple color change c. Indole test i. Differentiates between indole-positive (e.g., Escherichia coli, Proteus vulgaris) and indole-negative (e.g., Streptococcus pyogenes, Salmonella typhimurium) bacteria ii. Positive test: red color on the surface of the tube

a. Simple stain b. Gram stain

Skill Box 4.14 / Staining Solutions and Procedures The first step to identification of microbiology slides is to properly prepare the slide. All staining of slides should be done on an air-dried heat-fixed slide. To heat-fix a slide, make several rapid passes of the slide over a flame source (e.g., matches, lighter, or Bunsen burner). Once the slide has been immersed in staining solution, it should be agitated to allow fresh stain to remain in contact with its surface. Staining Technique

Uses

Preparation

Procedure

Interpretation

Diff-Quik (modified Wright’s stain)

General cytology and demonstration of bacteria

• Fixative: methanol, triarylmethane dye • Eosinophilic: xanthene dye • Basophilic: thiazine dye mixture

1. Dip the prepared slide 5 times slowly in methanol fixative. 2. Repeat above with eosinophilic stain and basophilic stain. 3. Rinse with water. 4. Air dry.

• Clear differentiation of cellular morphology • Staining ranges from pale pink to dark purple.

Giemsa Stain

Detection of spirochetes and rickettsiae

• Fixative: methanol • Giemsa powder • Glycerol

1. Fix the prepared slide in absolute methanol for 3–5 minutes and air dry. 2. Place the slide in diluted stain; 0–30 minutes. 3. Rinse with water and air dry.

• Purplish-blue stained bacteria

Differential Stains

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4

Skill Box 4.14 / Staining Solutions and Procedures (Continued) Staining Technique

Uses

Preparation

Procedure

Interpretation

Gram Stain

Distinguish between gram-positive and gram-negative bacteria based on their cell wall structure

• Primary stain: crystal violet • Mordant: Gram’s iodine • Decolorizer: alcohol • Counterstain: dilute carbol fuchsin or safranin

1. Flood the prepared slide with crystal violet; 30–60 seconds. 2. Rinse with water for 5 seconds. 3. Flood the slide with ram’s iodine; 30–60 seconds. 4. Rinse with water for 5 seconds. 5. Decolorize until the purple color is gone; ∼10 seconds. 6. Rinse with water for 5 seconds. 7. Flood the slide with dilute carbol fuchsin; 30–60 seconds. 8. Rinse with water for 5 seconds. 9. Air dry or blot between towels.

• Purple-stained bacteria are gram-positive. • Red-stained bacteria are gram-negative.

Lactophenol cotton blue

Detection of fungi

• Lactophenol cotton blue

Same as simple stain

• Visualization of hyphae, septae, and structure of spores

Ziehl/Neelson or Acid-Fast Stain

Detection of Mycobacterium spp. and Nocardia

• Carbol fuchsin • Acid alcohol • Methylene blue

1. Flood the prepared slide with carbol fuchsin and heat over a flame until it steams and then let it sit; 5 minutes. 2. Rinse with water. 3. Decolorize with acid alcohol until the red color is gone; 1–2 minutes. 4. Rinse with water. 5. Counterstain with methylene blue; 2 minutes. 6. Rinse with water and dry over low heat.

• Acid-fast bacteria stain red. • Non–acid-fast bacteria stain blue.

Modified Ziehl/ Neelson Stain With Brilliant Green

Detection of Mycobacterium spp. and Nocardia

• Carbol fuchsin • Acid alcohol • Brilliant green

1. Flood the prepared slide with carbol fuchsin; 3 minutes then heat. 2. Rinse with water. 3. Decolorize with acid-alcohol; 3 minutes. 4. Rinse with water. 5. Counterstain with brilliant green; 3 minutes. 6. Rinse and dry.

• Acid-fast bacteria stain red. • Non–acid-fast bacteria stain green.

Modified Ziehl/ Neelson Stain With Methylene Blue

Detection of Brucella, Nocardia, and Chlamydia

• Carbol fuchsin • Acetic acid • 0.5% Methylene blue

1. Flood the prepared slide with dilute carbol fuchsin; 10 minutes. 2. Rinse with water. 3. Decolorize with acetic acid; 20–30 seconds. 4. Rinse with water. 5. Counterstain with methylene blue; 2 minutes. 6. Rinse and dry.

• Brucella and Chlamydia stain bright red and in clumps.

4

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Skill Box 4.14 / Staining Solutions and Procedures (Continued) Staining Technique

Uses

Preparation

Procedure

Interpretation

Detection of capsules and difficult to stain bacteria (e.g., spirilli)

A negatively charged chromogen stain • India ink • Nigrosin

1. Prepare an air-dried slide. 2. Apply 1–2 drops of stain to prepared slide. 3. Apply coverslip and examine as a wet mount.

• Capsules appear clear and unstained, surrounded by dark particles.

Demonstration of bacteria and general morphology and shape arrangement

A positively charge chromogen stain • Carbol fuschin • Crystal violet • Methylene blue • New methylene blue • Safranin

Technique #1 1. Place 1 drop on the coverslip and apply to prepared slide. 2. Place a paper towel over the coverslip and apply gentle pressure to absorb excess stain. Technique #2 1. Place 1 drop of stain next to the coverslip on a prepared slide and allow the stain to leak under the coverslip. 2. Place a paper towel over the coverslip and apply gentle pressure to absorb excess stain.

Simple Stains Negative Staining

Simple Stain

4 • Visualization of cell shape and arrangement • Reticulocytes, Heinz bodies, urine sediments, and oily preparations (e.g., suspected lipomas using new methylene blue)

Note: Stains should be periodically filtered, using filter paper to remove any precipitate that may have formed. Note: Rinse slides on the reverse side to avoid disturbing the sample. Note: If a slide is overstained with Diff-Quik, place the slide in methanol for several minutes to destain and then restain. If the slide is understained with Diff-Quik, restain the slide with the appropriate stain color.

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Skill Box 4.15 / Staining Problems To avoid staining problems, use fresh clean stains and slides, do not touch the surface of the slide, and immediately stain slides after air-drying. Problem

Solution

Excessive Staining

• • • •

↓ Staining time Rinse adequately between stains and after staining. Prepare a thinner sample on the slide. Allow slide to dry before applying coverslip.

Weak Staining

• • • •

↑ Staining time Change stains. Stain slides sooner after air-drying. Keep the caps tightly placed on the stain containers to prevent evaporation.

Uneven Staining

• • • • •

Use only clean and dry slides. Do not touch the sample area of the slides before or after preparation. Place slides at an angle for drying to prevent liquid from drying onto the slide. Inadequate mixing of stains. Keep the caps tightly placed on the stain containers to prevent contamination and evaporation.

Slide Precipitate

• • • • •

Rinse adequately between stains and after staining (refer to Skill Box 4.14), page 127. Use clean slides. Do not allow stains to dry onto slide while staining. Change or filter stains periodically and regularly. Keep the caps tightly placed on the stain containers to prevent contamination and evaporation.

4

Table 4.20 / Bacteria Identification Organism

General Information

Associated Conditions

Microscopic

Culture

Bordetella bronchiseptica

• Gram-negative

• Upper respiratory infection and pneumonia

• Small rods

• BA: small, circular, dewdrop shape with +/− beta-hemolysis; slow grower • MC: weak growth

Borrelia burgdorferi

• Spirochete

• Lyme disease

• Refer to reference laboratory for identification.

• Refer to reference laboratory for identification

Brucella canis

• Gram-negative

• Infertility, abortion, and diskospondylitis

• Small, red coccobacillus in clumps

• BA: round, smooth, glistening, and translucent

Campylobacter spp. • Color Plate 4.10, CP-5

• Gram-negative • Does not survive outside the host ≥3 hours

• Gastroenteritis, infertility, and abortion

• Tiny, curved, gram-negative rods (not tightly spiraled) • Two attached together as a “seagull” or W shape • “Swarm of bees,” rapid and darting motility

• Refer to reference laboratory for identification.

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Table 4.20 / Bacteria Identification (Continued) Organism

General Information

Associated Conditions

Microscopic

Culture

Chlamydia

• Resemble gram-negative • Obligate, intracellular parasite

• Conjunctivitis and pneumonia

• Small, red, pleomorphic coccobacilli in clumps

• N/A

Clostridium • Color Plate 4.8, CP-4

• Gram-positive • Obligate anaerobes • Resistant to most disinfectants, requires 20 minutes of boiling or 121º C in an autoclave for 20 minutes

• Gastroenteritis, otitis and tetanus

• Large, spore-forming rods with rounded ends • “Safety pin” appearance with a swollen, clear center and dark staining ends

• BA: 1–3 mm in diameter, round to slightly irregular, raised, granular, transparent with a double zone of hemolysis • MC: no growth

Escherichia coli

• Gram-negative • Facultative anaerobes • Readily killed by disinfectants, sunlight, and desiccation

• Genital tract infection, musculoskeletal infection, pneumonia, enteritis, abscesses, urinary tract infection, and sepsis

• Small, non–spore-forming rods

• BA: large, smooth, gray, mucoid colonies with +/− hemolysis • MC: red growth, lactose fermentation, hemolytic pattern

Fusobacterium

• Gram-negative • Obligate anaerobes

• Pleuritis and abscesses

• Slender, long rods with pointed ends and long beaded filaments

• BA: small, smooth, convex and whitish-yellow in color colonies with a narrow zone of alpha- or beta-hemolysis

Mycobacterium tuberculosis

• Gram-positive

• Pulmonary nodules (dogs) and gastrointestinal problems (cats)

• Small, straight or slightly curved acid-fast rods, singly or in clumps

• Refer to a reference laboratory for identification

Mycoplasma spp.

• Gram-positive • Lack a cell wall; therefore do not stain adequately enough to evaluate • Readily killed by common disinfectants

• Genital tract infection, arthritis, conjunctivitis (cats) and pneumonia

• Small, coccobacillus-like, non– spore-forming, no cell wall and +/− pleomorphic

• Refer to a reference laboratory for identification

Nocardia spp.

• Gram-positive aerobes • Saprophyte in the soil • Partially acid-fast

• Pleuritis and abscesses in multiple tissues

• Branching, filamentous rods or coccobacilli

• BA: irregularly folded, raised, smooth to rough with a dry granular texture; slow grower • MC: no growth

Pasteurella spp.

• Gram-negative • Facultative anaerobes • Readily killed by most common disinfectants

• Conjunctivitis, genital tract infection, upper respiratory infection, pneumonia, pleuritis, abscesses and urinary tract infections

• Small, non–spore-forming coccobacilli or rods

• BA: round, smooth, gray colonies with +/− hemolysis • MC: no growth

Proteus spp.

• Gram-negative • Facultative anaerobes • Readily killed by common disinfectants, sunlight and dessication

• Cystitis, urinary tract infections, diarrhea, wounds and otitis

• Medium-sized non–spore-forming rods

• BA: large, smooth, gray, swarming, mucoid colonies with +/− hemolysis • MC: colorless growth that may spread

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4

Table 4.20 / Bacteria Identification (Continued)

4

Organism

General Information

Associated Conditions

Microscopic

Culture

Pseudomonas spp.

• Gram-negative • Killed by most common disinfectants, ↑ resistance to high dilutions of quaternary ammonium compounds and phenolic compounds

• Conjunctivitis, otitis musculoskeletal infection, abscesses, and urinary tract infections

• Small rods

• BA: 3–5 mm in diameter, irregular, spreading, translucent, bluish-metallic sheen, betahemolysis and grape-like odor • MC: yellow-green pigmented growth with a grape-like odor

Rickettsia

• Resemble gram-negative • Obligate, intracellular parasite • Smallest organism able to reproduce on its own • Can not live outside the host

• Rocky Mountain spotted fever, salmon poisoning disease, Ehrlichia and Hemobartonella

• Small, pleomorphic coccobacilli

• N/A

Salmonella

• Gram-negative • Readily killed by common disinfectants, sunlight, and dessication

• Gastroenteritis, abortion, hepatitis, and septicemia

• Small, non–spore forming rods

• BA: large, smooth, gray, mucoid colonies with +/− hemolysis • MC: colorless growth

Spirochetes • Color Plate 4.11, CP-5

• Gram- negative

• Lyme disease, leptospirosis,

• Stiff corkscrew helical rods with tight spirals • Corkscrewing motility

• N/A

Staphylococcus aureus/intermedius

• Gram-positive • Stable, surviving for months when dried in pus or other body fluids • ↑ Resistance to common disinfectants

• Conjunctivitis, genital tract infection, mastitis, pyoderma, otitis, osteomyelitis, musculoskeletal infection, pneumonia, abscesses and urinary tract infections

• Cocci, often in grape-like clusters, non–spore forming, +/− capsules

• BA: 4 mm in diameter, round, smooth, glistening with a double zone of hemolysis and gold pigmentation • MC: no growth

Streptococcus spp.

• Gram-positive • Facultative anaerobes • Remain living for weeks to months after being expelled from the body • Readily killed by common disinfectants

• Conjunctivitis, genital tract infection, otitis, pneumonia, abscesses, and urinary tract infections

• Cocci, +/− singly or in chains of varying lengths and non–spore forming

• BA: 1 mm in diameter, round, smooth, glistening and resemble dewdrops with beta-hemolysis (Alpha and gamma-hemolysis are typically normal flora) • MC: no growth

Note: BA = blood agar, MC = MacConkey agar.

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Table 4.21 / Fungi Identification Organism

Associated Conditions

Microscopic

Culture

Aspergillus

• Nasal infections • Common laboratory contaminant

• Preparation: clear cellophane tape with lactophenol blue or scrapings mixed with 10% sodium hydroxide • Identification: short pieces of thick, septate hyphae

• • • •

Blastomyces —Dermatitidis

• Pulmonary nodules, internal ulcers • Abscesses

• Preparation: wet mount with 20% KOH • Identification: large, oval or spherical, thick-walled with a single bud that is connected to the mother cell by a wide base

• Refer to reference laboratory for confirmation by culture.

Candida spp. • Color Plate 4.12

• Mycotic stomatitis (canine) • Enteritis (kittens)

• Preparation: scrapings of lesions made as wet mounts with 20% KOH, India ink, or lactophenol cotton blue • Identification: thin-walled (no capsule) oval budding yeast cells and +/− pseudohyphae

• • • •

Coccidiodes immitis

• Systemic and bone infections

• Preparation: unstained wet mounts • Identification: thick-walled sporangia

• Caution: Because of its zoonotic potential, refer to a reference laboratory for culture.

Cryptococcus —neoformans

• Paranasal and CNS infections

• Preparation: A small amount of discharge is mixed on a slide with water and India ink in a 1 : 2 ratio • Identification: budding yeast-like cells with large capsules

• • • •

Histoplasma capsulatum

• Systemic, pulmonary and gastrointestinal infections • Soil borne

• Preparation: Giemsa or Wright’s method • Identification: small oval cells surrounded by a halo seen intracellularly in monocytic cells

• Caution: Because of its zoonotic potential, refer to a reference laboratory for culture.

Malassezia –pachydermatis • Color Plate 4.34, CP-11

• Chronic otitis externa (canine) • Pyoderma

• Preparation: wet mounts with 10% NaOH • Identification: oval or bottle-shaped, small budding cells

• • • •

Microsporum canis

• Dermatophytosis

• Preparation: place a few pieces of plucked hair, scales, or crust from skin scraping, 20% KOH, and black India ink on a slide, and apply a coverslip with gentle pressure • Gently heat the slide, and let it sit for 10–15 minutes. • Identification: spores and chains of highly refractile arthrospores

• Medium: dermatophyte test medium (DTM, modified Sabouraud dextrose agar) • Additive: Phenol red, pH indicator • Incubation: 2 weeks at room temperature • Identification: flat colony, white surface and silky in center, red color change to agar

Medium: Blood agar or Sabouraud dextrose agar Additive: none Incubation: 48 hours at 77–98.6º F Identification: flat, white, and floccose, then turns green to dark green and powdery

4

Medium: Blood agar or Sabouraud dextrose agar Additive: none Incubation: 2 days at 77–98.6º F Identification: creamy, smooth colonies with yeastlike odor

Medium: Blood agar or Sabouraud dextrose agar Additive: none Incubation: 14 days at 95–98.6º F Identification: wrinkled, whitish granular colonies to mucoid, cream to brown colonies

Medium: Blood agar or Sabouraud dextrose agar Additive: Olive or coconut oil Incubation: 14 days at 77º F in a CO2 incubator Identification: greenish pigmentation

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133

Handling

PARASITOLOGY Fecal analysis is 1 of the most common laboratory tests run in small animal clinics. The skills required for preparing and reading these tests are minimal and are expected of every technician. Regardless of their simplicity, the result of these tests and subsequent treatment often leads to a full recovery by the patient.

• Samples should be handled carefully to avoid human contamination. • Maintain a clean environment in which to run the laboratory tests. • Maintain clear records as to the procedure performed. Storage • Fecal samples can be stored in whirl pak bags, small plastic sandwich bags, plastic containers, or disposable laboratory gloves turned inside out.

Fecal Collection, Handling, Storage, and Transport Tips 4 Collection

• Samples can be stored indefinitely in 10% formalin (1 part feces to 9 parts formalin), with minor limitations.

• Sample must be as fresh as possible because of rapid development of eggs once passed. • Owner should witness animal defecating to ensure freshness and observe for any straining, fresh blood, or other problems.

• Samples should not be stored by freezing, 70% ethyl alcohol, or 100% methyl alcohol. Transport

• Fresh samples not to be examined in 2 hours should be refrigerated for no longer than 24 hours.

• Sample should be cooled to 39.2º F in the refrigerator and then packed on ice or cold packs for 24–48 hours.

• Submit the amount equal to the size of an adult male’s thumb, at least 10 g.

• Place important papers in a separate plastic bag in case of sample fluid leakage.

• Sample should be clearly marked with patient’s name, number, time of collection, and whether it was refrigerated.

Skill Box 4.16 / Endoparasite Examination Methods Method

Uses

Technique

Comments

Gross Examination

• Consistency • Color • Blood, mucus, or adult parasites

• Visualize the feces or vomitus.

• Reveals conditions (e.g., blood) not seen in other methods

Direct Smear: Wet Prep

• Protozoa (e.g., Giardia) • Parasite burden • Bacteria (e.g., spirochetes, Cryptosporidium, Campylobacter)

1. Place a drop of saline or water with an equal amount of feces on a slide. Thoroughly mix the feces and water and smear to make a thin film over slide. 2. Remove any large pieces of feces and add a coverslip to examine. 3. Examine under ×10 for parasite eggs, ×40 for protozoal organisms, and ×100 for bacteria. • Stain can be added to the side of the coverslip for clearer identification.

• No egg distortion • Not a concentrated technique (small sample size) leading to low numbers • Motility can be a helpful diagnostic aid

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Skill Box 4.16 / Endoparasite Examination Methods (Continued) Method

Uses

Technique

Comments

Direct Smear: Dry Prep

• Protozoa (e.g., Giardia) • Parasite burden • Bacteria (e.g., spirochetes, Cryptosporidium, Campylobacter)

1. Place a small amount of feces on a slide and thinly spread out using an applicator stick. 2. Heat fix and stain with Diff-Quik. 3. Examine under ×10 for parasite eggs, ×40 for protozoal organisms, and ×100 for bacteria.

• No egg distortion • Not a concentrated technique (small sample size) leading to low numbers • Not able to judge motility of parasites

Standard or Simple: Flotation

• Most parasites • Parasite burden

1. Place 1–2 g feces in a suitable container (e.g., paper cup) and add flotation solution. 2. Mix the contents thoroughly with a tongue depressor and strain through a tea strainer or cheesecloth into a second container. 3. Pour this mixture into a test tube and add more flotation solution until a meniscus is formed. 4. Place a glass coverslip over the meniscus for 10–15 minutes. 5. The coverslip is then removed, placed on a slide, and examined.

• Commercial fecal flotation kits available • Less efficiently recovers eggs than the centrifugal flotation method • Misses larvae that settle because of gravity

Centrifugal Flotation

• Most parasites • Parasite burden

1. Mix 1 tsp feces in a paper cup with enough water or flotation solution to make a semisolid suspension. 2. Place a tea strainer or cheesecloth over a second paper cup, and empty the contents on top of it. 3. Push the liquid through the strainer with the tongue depressor and then discard the solid waste. 4. Pour the strained mixture into a 15 mL centrifuge tube. 5. Fill the tube with flotation solution to form a slight positive meniscus; do not overfill the tube. 6. Place a coverslip on top of the tube. 7. Put the tube in a balanced centrifuge and spin at 1,300 RPM for 5 minutes. 8. Remove the tube and let it stand for 10 minutes. 9. Lift the coverslip directly upward and place on a glass microscope slide.

• More efficiently recovers eggs than the standard flotation method • Requires a centrifuge with a horizontal rotor and the ability to hold 15-mL tubes • Misses larvae that settle because of gravity

Baermann Technique

• Nematode larvae

1. Fill the funnel with warmed water or physiologic saline (86º F) to cover the wire screen. 2. Spread a piece of cheesecloth or gauze square over the wire screen in the funnel. 3. Place 5–15 g feces, soil, or tissue on the cheesecloth and fold any excess cloth over the sample. Make sure that the warm water covers the sample. 4. Leave the sample undisturbed overnight (>8 hours). 5. Place a glass slide under the cut-off pipette and allow 1 drop of the liquid to fall onto the slide. 6. Apply a coverslip and examine. If the slide is negative, repeat several times for assurance.

• Efficient recovery of larvae

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Skill Box 4.16 / Endoparasite Examination Methods (Continued) Method

Uses

Technique

Comments

Fecal Culture

• Hookworm larvae • To distinguish between parasites that have similar-appearing eggs and cysts

1. Place feces in a glass jar rinsed with 0.1% sodium carbonate solution or on a piece of filter paper in a Petri dish. 2. Cover the container and place in a dark area for 7–10 days. There should be enough moisture in the container to produce condensation on the sides; if not, add a small amount of water. 3. After 7–10 days, rinse the container with a small amount of water, collect liquid, and centrifuge. 4. Examine the sediment with a microscope.

• Guaranteed identification

Wet Mount/Fecal Culture • InPouchTM

• Tritrichomonas foetus

Following the manufacturer’s instructions: Remove the pouch from the bag and confirm that ∼1 mL of liquid is in the upper chamber. Open the pouch and insert an applicator stick with 0.03 g of fresh feces or a coated swab into the liquid of the upper chamber. Remove the feces by gently rubbing the stick between thumb and forefinger and walls of chamber. Close the pouch and label. Wet Mount Stand the pouch upright for 15 minutes to concentrate T. foetus at the bottom of the pouch. Place the viewing clip horizontally across the pouch and then lay the pouch across the microscope and examine, paying special attention to the edges. Fecal Culture Squeeze all liquid into the lower pouch, close pouch, and incubate for 18–24 hours. Mix the pouch up and down against an edge 3–4 times. Place the viewing clip horizontally across the pouch and then lay the pouch across the microscope and examine.

• The addition of excess fecal material will make the medium too cloudy to view. • If no T. foetus is seen, evaluate daily for 2–4 days and up to every other day for 12 days. • 1–10 organisms is sufficient to result in a presumptive positive test. • Fecal culture is typically more accurate than the wet mount.

4

Note: A dried tapeworm proglottid may be rehydrated by soaking in water or physiologic saline for 1–4 hours. Note: Additional fecal cytology information can be found at Skill Box 4.7 Fecal Cytology, page 95.

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SECTION THREE: DIAGNOSTIC SKILLS

Skill Box 4.17 / Fecal Flotation Solutions Fecal flotation solutions are used to assist in the discovery of parasitic eggs in fecal material. The solution chosen must have a specific gravity that allows parasite eggs to float and the bulk of fecal material to sink. Because water has a specific gravity just slightly lower than many parasite eggs, sugar or salts are added to increase the solution’s specific gravity and allow the eggs to float. The desired specific gravity is between 1.2 and 1.25 g/mL. Solutions with a specific gravity >1.35 g/mL will allow both debris and parasite eggs to float, making egg identification more difficult. A specific gravity <1.10 will force both debris and parasite eggs to sink, giving no diagnosis. Solutions that are purchased premixed are preferred because of quality control. Solutions mixed in the clinical setting tend to have less quality control and give variable results. Almost all solutions will form crystals on the slide if left sitting. Media

Preparation

Specific Gravity

General Information

Magnesium Sulfate

• Magnesium sulfate: 400 g • Tap water: 1,000 mL

1.20

• Readily available and inexpensive

Sodium Chloride

• Sodium chloride: 400 g • Tap water: 1,000 mL • Stir while adding the sodium chloride to water. Heating is not necessary, but speeds the dissolution.

1.18–1.20

• Readily available and inexpensive • Corrodes expensive laboratory equipment • Severely distorts eggs

Sodium Nitrate

• Sodium nitrate: 400 g • Tap water: 1,000 mL • Stir while adding the sodium nitrate to water. Heating is not necessary, but speeds the dissolution.

1.20

• • • •

Floats the greatest percentage of eggs Can be purchased in a ready-to-mix solution Distorts the eggs after 15 minutes May not be readily available and more expensive

Sugar Solution, Sheather’s Solution

• Granulated sugar: 454 g • Tap water: 355 mL • Dissolve sugar in water by heating on low heat and stirring. Add 2 mL of 37% formaldehyde or phenol crystals to prevent bacterial growth.

1.27–1.33

• • • •

Readily available and inexpensive Does not distort eggs or crystallize Floats an adequate percentage of eggs Best if used with centrifugal flotation technique

Zinc Sulfate

• Zinc sulfate: 371 g • Tap water: 1,000 mL • Stir while adding the zinc sulfate to water. Heating is not necessary, but speeds the dissolution.

1.18

• Best for intestinal protozoa (e.g., Giardia) • Light must be ↓ and focused immediately under the coverslip. • Floats a high percentage of eggs

Note: If a fecal sample is left for more than 1 hour, the eggs may become waterlogged, resulting in distortion or sinking to the bottom.

CHAPTER 4 / LABORATORY

137

4

Skill box 4.18 / Blood Parasite Examination Methods Method

Uses

Technique

General Information

Direct Examination

• Microfilariae

1. Add 1 drop of blood to a slide. 2. Add a coverslip and examine for movement.

• Small sample volume owing to low sensitivity

Thin Blood Smear

• Trypanosomes, protozoans, and rickettsia

1. Place a drop of blood near 1 end with a glass slide laying on a flat surface 2. Place another slide at a 30%–40% angle in front of the blood. 3. Back the slide up until the blood runs along the edge of the second slide. 4. Then gently and steadily push the slide forward and off the first slide, producing a smear with a feathered edge. 5. Air-dry, +/− add stain and examine.

• Small sample volume

Thick Blood Smear

• Microfilariae, protozoa, and rickettsiae

1. Place 3 drops of blood on a slide, spread the drop out with a wooden applicator stick into a 2-cm circle. 2. Air-dry the slide. 3. Place the slide in a slanted position in a container of distilled water. 4. Once the smear losses its red color, remove it, and allow it to air-dry. 5. Place the slide in methyl alcohol for 10 minutes 6. Add Giemsa stain for 30 minutes. 7. Rinse slide and examine.

• Larger sample volume

Buffy Coat

• Microfilariae

1. Fill and centrifuge an Hct tube for 3 minutes. 2. Using a file or glass slide, score the tube just below the buffy coat and snap apart. 3. Tap the tube until the buffy coat drops onto a glass slide. 4. Add a drop of saline and stain, place a coverslip on, and examine.

• Does not allow differentiation of microfilariae species

Modified Knott’s Technique

• Microfilariae

1. Mix 1 mL whole unclotted blood with 9 mL 2% formalin in a test tube. 2. Centrifuge at 1,300–1,500 rpm for 5 minutes. 3. Pour off the supernatant and add 2–3 drops of stain to the sediment. 4. With a pipette, mix the sediment and stain. 5. Place a drop on a glass slide, apply a coverslip, and examine under ×10.

• Allows differentiation of microfilariae species

4

138

SECTION THREE: DIAGNOSTIC SKILLS

Skill Box 4.19 / Ectoparasite Examination Methods Method

Uses

Technique

General Information

Gross Examination

• Lice, mites, ticks, flies, or fleas

1. Visualize the ectoparasite on the animal or by using a flea comb.

• Limited number of parasites visible

Cellophane Tape

• Lice or mites

1. Bend the cellophane tape into a loop with the sticky side out. 2. Press the tape against the animal’s skin. 3. Put 1 drop of water on a slide and lay tape over it and press down. 4. Examine under a microscope.

• Limited number of parasites visible

1. Place a drop of mineral oil on a glass slide. 2. Roll the swab or material collected in the mineral oil to deposit any debris. 3. Place a coverslip on the slide and examine with a microscope, using 4× magnification.

• Most thorough technique for ectoparasite diagnosis

Microscopic Examination

• Most ectoparasites

4

Table 4.22 / Endoparasites (See figures in Color Plate 11–13)

Prevention of human infection from endoparasites involves proper hygiene (e.g., washing hands and properly cooking food), isolation of infected animals, and quarantine of newly acquired animals. Each fecal sample should be thought of as a zoonotic risk and treated appropriately.

Figure 4.35 Relative size of parasite eggs. Note: Adapted from Veterinary Parasitology Reference Manual by William J. Foreyt.

Parasite

Transmission Route

Clinical Signs

Diagnostics

Common Treatments

Ancylostoma caninum ZOONOTIC • Common Name: Southern hookworm • Type: Nematode • Affected Species: Canine • Disinfection: Bleach • Environment: Can live in cool, moist soil for several weeks • Image: Color Plate 4.36

Eggs passed → ingestion, percutaneous, prenatal and transmammary → lungs for development → coughed up and swallowed → small intestines to mature • Prepatent period: 2 weeks

• Anemia, weakness, inappetance, poor growth, dry cough, diarrhea, constipation, and dark tarry stools

• Fecal flotation • Egg: oval or ellipsoid, capsule-shaped, 8–16 cells inside a thin wall • Sample must be <48 hours old because eggs larvate rapidly in the external environment.

• • • • • • • • • • •

Butamisole Dichlorvos Diethycarbamazine/oxibendazole Febantel/praziquantel Fenbendazole Ivermectin Lufenuron + milbemycin Mebendazole Milbemycin oxime Moxidectin Pyrantel CHAPTER 4 / LABORATORY

139

Table 4.22 / Endoparasites (Continued)

4

Parasite

Transmission Route

Clinical Signs

Diagnostics

Common Treatments

Ancylostoma tubaeforme ZOONOTIC • Common Name: Feline hookworm • Type: Nematode • Affected Species: Feline • Disinfection: Bleach • Environment: Can live in cool, moist soil for several weeks • Image: Color Plate 4.37

Eggs passed → ingestion, percutaneous, prenatal and transmammary → lungs for development → coughed up and swallowed → small intestines to mature • Prepatent period: 3–3.5 weeks

• Interdigital dermatitis, pulmonary lesions, anemia and poor hair coat

• Fecal flotation • Egg: oval or ellipsoid, capsule shaped, 8–16 cells inside a thin wall • Sample must be <48 hours old because eggs larvate rapidly in the external envirnoment.

• • • • • •

Dichlorvos Fenbendazole Milbemycin oxime Mebendazole Moxidectin Pyrantel

Cryptosporidium ZOONOTIC • Common Name: N/A • Type: Protozoa • Affected Species: Canine and feline • Disinfection: Heating >131º F for 15–20 minutes, thorough drying, 5% ammonia solution, and formaldehyde • Environment: Resistant for months • Image: Color Plate 4.38

Oocysts passed → ingested by definitive host → develop in the ileum and cecum • Prepatent period: 2–7 days

• Asymptomatic or diarrhea

• Fecal flotation, acid-fast staining, negative staining, ELISA and IFA tests • Oocysts: oval to spherical, thick-walled and sporulated • Note: difficult to distinguish from yeast cells on fecal flotations

• • • •

Clindamycin Tylosin Azithromycin Paromomycin

Dipylidium caninum ZOONOTIC • Common Name: Flea tapeworm • Type: Cestode • Affected Species: Canine and feline • Image: Color Plate 4.39

Proglottids passed and rupture to release thousands of eggs → ingested by intermediate host (flea and biting lice) → development → definitive host ingests the intermediate host → attaches to lining of small intestines to mature • Prepatent period: 4 weeks

• Anal pruritus, chronic enteritis, vomiting, or nervous system disorders

• Fecal flotation or visual examination of feces, perianal area, or bedding • Egg: double-pored, rice or cucumber seed appearance, oblong packets of 20 eggs or less

• Epsiprantel • Febantel/Praziquantel • Praziquantel

Dirofilaria immitis ZOONOTIC • Common Name: Heartworm • Type: Nematode • Affected Species: Canine and feline • Image: Color Plate 4.40

• Intermediate host (mosquito) must carry the larva for 15–17 days with the temperature ≥58º F → intermediate host infects definitive host → larva passes from venous circulation to heart → resides in pulmonary arteries and right ventricle of heart → microfilaria circulate in blood and are picked up by intermediate host (mosquito) • Prepatent period: 24 weeks

• Murmur, lack of stamina, weight loss, chronic cough, obstruction of pulmonary vessels, and congestive heart failure

• Knott’s test, buffy coat examination, direct blood smear, millipore filtration of blood, and various serologic tests for antigen of adult worm • Microfilaria: straight with 1 tapered end and 1 straight end

Adulticides • Caparsolate • Malarsomine • dihydrochloride Microfilariacides • Diethylcarbamazine • Diethycarbamazine/oxibendazole • Dithiazine • Ivermectin • Levamisole • Milbemycin oxime • Moxidectin • Selamectin

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SECTION THREE: DIAGNOSTIC SKILLS

Table 4.22 / Endoparasites (Continued) Parasite

Transmission Route

Clinical Signs

Diagnostics

Common Treatments

Echinococcus granulosus and multiocularis ZOONOTIC • Common Name: Canine and feline tapeworm, respectively • Type: Cestode • Affected Species: Canine and feline • Image: Color Plate 4.41

Proglottids passed → ingested by intermediate host (e.g., cattle, swine, sheep and rodents) → attaches to liver → definitive host ingests the intermediate host → attaches to lining of small intestines to mature • Prepatent period: 4 weeks

• Diarrhea • Hydatid cyst disease in intermediate host

• Fecal flotation or purging the animal and collecting the clear mucus at the end • Egg: ovoid containing a single oncosphere with 3 pairs of hooks • Note: indistinguishable from Taenia spp. eggs

• Mebendazole • Praziquantel

Filaroides osleri • Common Name: Tracheal worm and canine lungworm • Type: Nematode • Affected Species: Canine

Eggs passed → ingested (passed from dam to pup through grooming or regurgitated meals) → migrate to small intestines and then to lungs to develop → migrate to oral cavity or passed through feces • Prepatent period: 10 weeks

• Coughing and chronic tracheobronchitis with nodule formation in large airways

• Fecal flotation, Baerman technique, and sputum smear • Larva: short, with an Sshaped tail

• Albendazole • Ivermectin

Giardia ZOONOTIC • Common Name: Giardia • Type: Protozoa • Affected Species: Canine and feline • Disinfection: Bleach and quaternary ammonium • Image: Color Plates 4.12 and 4.42

Eggs passed → ingested → migrate to small intestines • Prepatent period: 5–7 days

• Asymptomatic or diarrhea (appearing pale and greasy with a foul odor)

• Fecal flotation, direct fecal smear, and IFA • Active form: pear-shaped with the anatomy resembling a face of crossed eyes, nose, and a mouth

• Furazolidone • Metronidazole

Isospora canis/felis ZOONOTIC • Common Name: Coccidia • Type: Protozoa • Affected Species: Canine and feline • Disinfection: Incineration, steam cleaning, immersion in boiling water and 10% ammonia solution • Prevention: Insect and rodent control and sanitation • Environment: Extremely resistant to environmental conditions • Image: Color Plate 4.43

Eggs passed, usually by mother → ingested, often by puppy or kitten → develop to a trophozoite → migration to intestines • Prepatent period: 1–2 weeks

• Asymptomatic or diarrhea progressing to vomiting, inappetance, and dehydration

• Fecal flotation • Egg: small, oval, and thin-walled • Sporulated: 2 sporocysts per egg • Unsporulated: 1 cell stage inside egg

• • • •

4

Furazolidone Sulfadiazine + trimethoprim Sulfadimethoxine Toltrazuril

CHAPTER 4 / LABORATORY

141

Table 4.22 / Endoparasites (Continued) Parasite

Transmission Route

Clinical Signs

Diagnostics

Common Treatments

Nanophyetus salminocola ZOONOTIC • Common Name: Salmon poisoning fluke • Type: Trematode • Affected Species: Canine

Eggs passed by definitive host (e.g., raccoon) → ingested by intermediate host (snail) → larva passed → ingested by intermediate host (salmon) → salmon ingested by definitive host (e.g., dog) → develop in intestines • Prepatent period: 1 week

• Lymph-adenopathy, depression, vomiting, and hemorrhagic enteritis • Caused by the rickettsial agent (Neorickettsia helminthoica) carried by the fluke

• Fecal flotation or fecal smear • Egg: gold, operculum at 1 end and blunt point at opposite end

Fluke • Praziquantel Rickettsial organism • Chloramphenical • Doxycycline • Oxytetracycline • Tetracycline

Spirocerca lupi • Common Name: Esophageal worm or park worm • Type: Nematode • Affected Species: Canine

Egg passed by definitive host (e.g., dog) → ingested by intermediate host (beetle) → ingested by paratenic host (e. g., lizards, birds, rodents) or definitive host (e.g., dog) → larva penetrate stomach wall and migrate through the arteries to the esophagus → forms a fistula and releases egg in the feces • Prepatent period: 5–6 months

• Dysphagia, regurgitation, vomiting, esophageal neoplasia, hypersalivation, hypertrophic osteopathy

• Fecal flotation (specific gravity >1.036) or fecal smear • Egg: thick walled, ellipsoid embryonated egg

• Disophenol sodium • Ivermectin • Doramectin

Taenia pisiformis • Common Name: Tapeworm • Type: Cestode • Affected Species: Canine • Image: Color Plate 4.44

Proglottids passed → ingested by intermediate host (e.g., rabbit and ruminant) → attaches and develops in peritoneal cavity → definitive host ingests the intermediate host → develops in the small intestines • Prepatent period: 8 weeks

• Enteritis and intestinal obstruction

• Fecal flotation or visual exam of feces, perianal area or bedding • Egg: round and containing a single oncosphere with 3 pairs of hooks • Each proglottid carries many eggs

• • • • •

Epsiprantel Febantel + praziquantel Fenbendazole Mebendazole Praziquantel

Taenia taeniaeformis • Common Name: Feline tapeworm • Type: Cestode • Affected Species: Feline

Proglottids passed → ingested by intermediate host (e.g., rodent) → attaches and develops in the liver → definitive host ingests the intermediate host → develops in the small intestines • Prepatent period: 5–6 weeks

• Diarrhea and intestinal blockage

• Fecal flotation or visual examination of feces, perianal area, or bedding • Egg: ovoid containing a single oncosphere with 3 pairs of hooks • Each proglottid carries many eggs

• • • • •

Epsiprantel Febantel + praziquantel Fenbendazole Mebendazole Praziquantel

4

142

SECTION THREE: DIAGNOSTIC SKILLS

Table 4.22 / Endoparasites (Continued) Parasite

Transmission Route

Clinical Signs

Diagnostics

Common Treatments

Toxascaris leonina ZOONOTIC • Common Name: Ascarid, roundworm • Type: Nematode • Affected Species: Canine and Feline • Disinfection: Bleach • Environment: Eggs can remain infective in the soil for months to years • Image: Color Plate 4.45

Eggs passed → ingested by definitive host or intermediate host (e.g., mice) → definitive host ingests intermediate host → attaches and develops in small intestines • Prepatent period: 8–10 weeks

• Chronic diarrhea, vomiting, constipation, and unthriftiness

• Fecal flotation or visual examination of feces • Egg: spherical to ovoid, unembyronated, light cytoplasm, and a smooth outer shell

• • • • • • •

Dichlorvos Diethylcarbamazine Fenbendazole Milbemycin oxime Mebendazole Piperazine Pyrantel

Toxocara canis ZOONOTIC • Common Name: Ascarid, roundworm • Type: Nematode • Affected Species: Canine • Disinfection: Bleach • Environment: Eggs can remain infective in the soil for months to years • Image: Color Plate 4.45

Eggs passed → ingested via environment or paratenic host → hatch in small intestines and penetrate mucosa → migrate through the liver and heart until the lungs → develop in lungs → coughed up and swallowed → mature in the small intestines for 4–6 weeks • Prepatent period: 4–6 weeks

• Distended abdomen, weakness, unthriftiness, and diarrhea

• Fecal flotation or visual examination of feces or vomitus • Egg: spherical, unembyronated, deeply pigmented center, and a rough, pitted outer shell

• • • • • • • • •

Dichlorvos Diethylcarbamazine Diethycarbamazine/oxibendazole Febantel + Praziquantel Fenbendazole Mebendazole Milbemycin oxime Piperazine Pyrantel

Toxocara cati ZOONOTIC • Common Name: Ascarid, roundworm • Type: Nematode • Affected Species: Feline • Disinfection: Bleach • Environment: Eggs can remain infective in the soil for months to years • Image: Color Plate 4.46

Eggs passed → ingested via environment or paratenic host → hatch in small intestines and penetrate mucosa → migrate through the liver and heart until the lungs → develop in lungs → coughed up and swallowed → mature in the small intestines for 4–6 weeks • Prepatent period: 7–8 weeks

• Stunted growth and damage caused by migrations

• Fecal flotation • Egg: spherical, unembyronated, deeply pigmented center, and a rough, pitted outer shell

• • • • • • • •

Dichlorvos Diethylcarbamazine Fenbendazole Lufenuron Mebendazole Piperazine Pyrantel Selamectin

CHAPTER 4 / LABORATORY

4

143

Table 4.22 / Endoparasites (Continued)

4

Parasite

Transmission Route

Clinical Signs

Diagnostics

Common Treatments

Toxoplasma gondii ZOONOTIC • Common Name: Toxoplasmosis • Type: Protozoa • Affected Species: Feline • Environment: Can live in the soil for months to >1 year • Image: Color Plate 4.47

Oocysts passed → ingested via environment, intermediate host (most warm-blooded vertebrates) or transplacental → migrate to small intestines and extraintestinal dissemination elsewhere via blood and lymph • Prepatent period: 3–10 days for ingestion of cysts and 20–40 days for oocysts

• Asymptomatic or transient diarrhea, anorexia, depression, fever, and clinical signs dependent on site and extent of injury from migration (e. g., CNS, hepatic, pulmonary)

• Fecal flotation, ELISA, or agglutination procedures • Oocysts: oval and unsporulated

• • • •

Clindamycin Pyrimethamine Sulfadiazine + trimethoprim Toltrazuril

Trichuris vulpis • Common Name: Whipworm, fecal jewel • Type: Nematode • Affected Species: Canine • Disinfection: Diluted sodium chloride • Environment: very resistant • Image: Color Plate 4.48

Eggs passed → ingested → penetrate and develop in small intestines → migrate to cecum and develop for 60–80 days • Prepatent period: 9–12 weeks

• Weight loss, intermittent and chronic diarrhea and typhlitis

• Fecal flotation • Egg: thick, brown-yellow symmetrical shell with clear polar plug at each end and unembyronated

• • • • • •

Diethycarbamazine/oxibendazole Febantel + praziquantel Fenbendazole Ivermectin Mebendazole Milbemycin oxime

Uncinaria stenocephala ZOONOTIC • Common Name: Northern canine hookworm • Type: Nematode • Affected Species: Canine and feline • Disinfection: Bleach • Environment: Can live in cool, moist soil for several weeks • Image: Color Plate 4.49

Eggs passed → ingestion, percutaneous, prenatal and transmammary → lungs for development → coughed up and swallowed → small intestines to mature • Prepatent period: 2 weeks

• Weakness, inappetance, poor growth, and diarrhea

• Fecal flotation • Egg: oval or ellipsoid, capsule shaped, 8–16 cells inside a thin wall • Sample must be <48 hours because eggs larvate rapidly in the external environment

• • • • • •

Dichlorvos Fenbendazole Ivermectin Mebendazole Milbemycin oxime Pyrantel

144

SECTION THREE: DIAGNOSTIC SKILLS

Table 4.23 / Ectoparasites (See figures in Color Plate 13–15) Parasite

Transmission Route

Clinical Signs

Diagnostics

Common Treatments

Cheyletiella ZOONOTIC • Common Name: Fur mite of dogs and cats and walking dander • Type: Mite • Affected Species: Canine and feline • Human Risk: Low • Image: Color Plate 4.50

• Ingest: keratin debris and tissue fluid • Location: skin • Transmission: direct contact and contact through inanimate objects • Life Cycle: 18–21 days

• Asymptomatic, mild alopecia, dandruff, and pruritus

• Scrape margins of lesions, flea comb, visual, or cellophane tape • Adult: body shape resembles a shield or acorn, hook-like accessory mouth parts and comb-like structures at the tip of each leg

• Ivermectin • Selamectin

Ctenocephalides canis/felis • Common Name: Flea • Type: Flea • Affected Species: Canine and Feline • Human Risk: Low • Image: Color Plate 4.51

• Ingest: blood • Location: head and base of tail • Transmission: direct contact or through contact with inanimate objects • Life Cycle: 21 days–>1 year

• Flea bite dermatitis, anemia, pruritus, red lesions, hair loss, and ulcers

• Visual and flea comb • Adult: medium brown to mahogany in color, laterally flattened body, 2–8 mm long with pronotal and genal combs • Transmit Dipylidium and Hemobartonella spp.

• • • • • • • •

Cuterebra • Common Name: Rodent botfly, warbles, and wolves • Type: Fly • Affected Species: Canine and feline • Human Risk: Low

• Ingest: N/A • Location: face and neck region, can be found on any furred area • Transmission: contact with rodent burrow or eggs from an adult fly • Life Cycle: 3–4 weeks

• Cutaneous lump with a breathing hole

• Visual Larvae • 2nd Stage: cream to white, toothlike spines and 5– 10 mm long • 3rd Stage: large, coal black, heavily spined, and up to 3 cm long

• Surgical removal of larvae • Note: do not crush larva when removing, because it may cause anaphylaxis • Wound treatment

Demodex canis • Common Name: Follicular mange mite, red mange, or puppy mange • Type: Mites • Affected Species: Canine • Human Risk: None • Image: Color Plate 4.52

• Ingest: unknown • Location: hair follicles and sebaceous glands • Transmission: direct contact from dam to pup; otherwise not contagious between hosts • Life Cycle: 21 days

• Alopecia of muzzle, face, and forelegs; erythema, 2º bacterial pyoderma, and pruritus

• Deep skin scrapings on squeezed skin or biopsy • Adult: cigar-shaped, 8 stubby legs at anterior end of body, and ¼ cm long

• • • •

Dermacentor variabilis/andersoni • Common Name: American dog tick and wood tick • Type: Tick • Affected Species: Canine • Human Risk: High • Image: Color Plate 4.53

• • • • •

• Asymptomatic or vasculitis • Intermediate host for Rocky Mountain spotted fever, tularemia, and other Rickettsia spp.

• Visual • Adults: blue-gray with white markings on shield

• • • • •

Ingest: blood Location: whole body Transmission: contact Life Cycle: 3 months–2 years Tick must be attached for 5–20 hours to transmit disease

4

Fipronil Imidacloprid Lufenuron Methoprene Nitenpyram Pyrethrins/pyrethroids Pyriproxyfen Selamectin

Amitraz 0.025% Ivermectin Milbemycin oxime Multivitamin/fatty acid supplement • Antibiotics • Benzoyl peroxide 5% (gel or shampoo) aids in penetration in the follicles when used with Amitraz Dichlorvos Fipronil Pyrethrins Pyriproxyfen Selamectin

CHAPTER 4 / LABORATORY

145

Table 4.23 / Ectoparasites (Continued)

4

Parasite

Transmission Route

Clinical Signs

Diagnostics

Common Treatments

Linognathus setosus • Common Name: Sucking louse of dogs • Type: Lice • Affected Species: Canine • Human Risk: Low • Environment: Live 7 days off host • Image: Color Plate 4.54

• • • • •

Ingest: blood Location: whole body Transmission: contact Life cycle: 3–4 weeks Definitive host: canine and feline

• Skin irritation, itching, dermatitis, alopecia, anemia, and roughened hair coat

• Visual • Adult: dorsoventrally flattened, red to gray in color, head is more narrow than the widest part of the thorax, and 1st pair of claws smaller than 2nd and 3rd pairs

• Fipronil • Ivermectin • Pyrethrins

Otodectes cynotis • Common Name: Ear mite • Type: Mite • Affected Species: Canine and feline • Human Risk: N/A • Image: Color Plate 4.55

• • • •

Ingest: epidermal debris Location: ear and base of tail Transmission: contact Life Cycle: 18–21 days

• Shaking of head, irritation, otitis media, hematomas, head tilt, circling, and convulsions

• Visual or ear swab • Adult: oval with 8 legs, fused head and thorax, short unjointed pedicle with suckers on the end of some of the legs

• Clean the ear of all crusty debris. • Ivermectin • Milbemycin oxime • Selamectin

Rhipicephalus sanguineus • Common Name: Brown dog tick • Type: Tick • Affected Species: Canine • Image: Color Plate 4.56

• • • •

Ingest: blood Location: whole body Transmission: contact Life Cycle: 6 weeks–1 year

• Anemia • Intermediate host for babesiosis and ehrlichiosis

• Visual • Adult: brown with prominent lateral extensions on head, giving a hexagonal appearance

• • • • •

Dichlorvos Fipronil Pyrethrins Pyriproxyfen Selamectin

Sarcoptes scabiei canis ZOONOTIC • Common Name: Mange mite or scabies • Type: Mite • Affected Species: Canine • Human Risk: low • Image: Color Plate 4.57

• Ingest: interstitial fluid • Location: ears, lateral elbows, and ventral abdomen • Transmission: contact • Life Cycle: 2–3 weeks

• Severe itching, dry and thickened skin, erythema, papular rash, scaling, crusting, and excoriations

• Deep skin scraping • Adults: oval with 8 legs, fused head and thorax, long unjointed pedicel with suckers on the end of some of the legs

• • • • •

Ivermectin Amitraz Benzyl benzoate Lime-sulfur Selamectin

Trichodectes canis • Common Name: Biting louse of dogs • Type: Lice • Affected Species: Canine • Environment: Live 7 days off host • Image: Color Plate 4.58

• • • •

• Itching, rough hair coat, and dermatitis

• Visual • Adult: dorsoventrally flattened, yellow, large rounded head; head is wider than any other part of the body, 2–4 mm

• Pyrethrins

146

SECTION THREE: DIAGNOSTIC SKILLS

Ingest: skin and hair Location: whole body Transmission: contact Life Cycle: 3–4 weeks

URINALYSIS

• Centrifuge the sample at 500–3000 rpm for 3–5 minutes.

Urinalysis is one of the most frequently performed laboratory tests in small animal clinics. Due to the filtering nature of the urologic system, information gained from this test may assist the veterinarian in a final diagnosis. Rarely does the urinalysis alone provide the diagnosis, but when interpreted along with clinical signs, blood chemistries, and other diagnostic tests, a diagnosis can be made. Even though this is a routinely done lab test, special care must be taken to ensure accurate results. Slight changes can make large alterations in the final results. As a technician, performing a complete urinalysis with great skill is a must.

• Gently pour off the supernatant to avoid disrupting the remaining pellet.

Urine Collection, Handling, Storage, and Transport Tips Collection • Collect before the administration of any medication, if possible. • Morning, prepandial samples offer the most accurate specific gravity, pH and cellular components, but allow for the degeneration of casts overnight in the bladder. • Collection containers must be clean, well rinsed, and free of any disinfectant residues.

• Gently mix the pellet to avoid cellular damage. Note: Applying the brake to produce an abrupt stop may resuspend the sediment and alter results. Storage • Samples at room temperature should be examined within 60 minutes. • Samples can be refrigerated for 6–12 hours in a covered container. • Refrigerated samples tend to form crystals. • Samples may be frozen for chemistry tests, but cellular components will be destroyed. Transport • Add 1–2 drops of serum to the sample to preserve cell morphology. • Add 1 drop of 40% formalin to each ounce of urine.

Urine Examination/Urinalysis

• Collect at least 3–5 mL of urine. • See Skill Box 12.8, page 434, and Skill Box 12.10, page 435, for procedural information on urine collection. Handling • Samples should be covered immediately to avoid pH changes and contamination. • Samples with a delay of examination of >1 hour should be refrigerated, delay in examination can lead to changes in all aspects of a urinalysis. • Thoroughly mix a sample before examination.

All urine samples should be evaluated for the following physical properties. Each of the assessments listed below is observed through a visual examination of the sample, except the specific gravity. The specific gravity is obtained with a refractometer, which accurately measures the amount of solids dissolved in a urine sample. The most accurate results are obtained with the supernatant, as it is free of cellular debris that may give false increases. The refractometer should be checked daily to ensure its calibration is set correctly. Using 1 drop of distilled water, the specific gravity reading should be 0.00.

• Slowly warm refrigerated samples up to room temperature before examination and likewise, allow urine to cool down to room temperature after collection.

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4

Table 4.24 / Gross Examination Physical Property

Observation

Definition

Associated Conditions

Color

Yellow

• Any shade of yellow is considered normal. • Variations are often attributable to changes in concentration (e.g., clear with low USG).

• N/A

Red or red/brown

• Cloudy, red urine is hematuria with intact RBCs. • Clear, red urine is hemoglobinuria with free hemoglobin.

• UTI, cystitis, trauma, neoplasia, urolithiasis

Brown

• Contains myoglobin

• Muscle cell lysis

Yellow/brown or yellow/green

• Contains bile pigments

• Liver disease

White

• Contains leukocytes

• UTI, cystitis, heavy crystalluria

Small amount

• Normal when sample is shaken

• N/A

Large amount

• Contains protein

• Kidney disease, fever, excessive exercise

Green

• Contains bile pigments

• Liver disease

Ammonia

• Breakdown of urease

• UTI, cystitis

Sweet, fruity odor

• Contains ketones and/or glucose

• Diabetes mellitus

Canine • 1.015–1.045 Feline • 1.035–1.060

• Normal • Measurement of the density of urine compared with pure water

• N/A

Canine • >1.045 Feline • ≥1.060

• Hyperthenuric • If dehydrated; canine: ≥1.030; feline: ≥1.035 • False ↑: ↑ glucose and protein

• ↑ Water intake or excretion of solutes • Cold urine produces a falsely high USG.

≤1.007

• Hypothenuric

• ↓ Water intake, pyometra, liver disease, kidney disease, diuretics, or diabetes insipidus

Clear

• Normal

• N/A

Cloudy or flocculent

• Contains cellular components

• UTI

Polyuria

• ↑ Urine production; pale with a ↓ USG (≤1.020)

• Nephritis, diabetes mellitus, diabetes insipidus, pyometra, liver disease, and kidney disease

Oliguria

• ↓ Urine production

• ↓ Water intake, fever, shock, heart disease, and dehydration

Pollakiuria

• Frequent urination

• UTI, urolithiasis, and crystalluria

Anuria

• Complete lack of urine output • No urine output in 12 hours

• Urinary obstruction, urinary bladder rupture, and death

4

Foam

Odor

Specific Gravity (USG)

Transparency

Volume

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Preparation Chemistry strip evaluation provides detection of elements present in a urine sample that may or may not be seen during visual examination or microscopic evaluation. Because chemistry strips provide many false-negative results, both a visual examination and a microscopic examination should always be performed. Chemistry strip bottles should be kept at room temperature and away from intense light, moisture, and heat. Strips can be immersed in a urine

sample for 2–3 seconds to allow saturation of the pads. Extended time may lead to test reagents leaking into the urine sample. A pipette or dropper also may be used to saturate each pad and then turning the strip on its side and tapping to eliminate excess urine. Allowing urine to run down the test strip can allow mixing of the chemical pads altering the results. The results are then read at the time indicated by the manufacturer in consistent artificial light to avoid the fluctuations seen with natural light. The color change can be subjective and also altered by the presence of urine pigments. (e.g., bilirubin, hemoglobin).

Table 4.25 / Chemistry Strip Examination Chemical Property

Observation

Definition

Associated Conditions

Bilirubin

Bilirubinuria

• A byproduct from the breakdown of hemoglobin • Trace amounts found in dogs if USG is ≥1.030, but not common in cats • False negative: exposure to light • Confirmation tests: Ictotest

• Hemolytic anemia, bile duct obstruction, liver disease, fever, and prolonged fasting or starvation

Blooda

Hematuria

• Presence of intact RBCs • After centrifugation, urine will appear clear with a red pellet.

• UTI, cystitis, renal disease, strenuous exercise, trauma, and genital tract contamination

Hemoglobinuria

• Presence of free hemoglobin, typically caused by intravascular hemolysis • After centrifugation, urine will remain tinted red.

• Hemolytic anemia, severe burns, incompatible transfusions, leptospirosis, babesiosis, systemic lupus erythematosus, and metal toxicity

Myoglobinuria

• Presence of myoglobin typically due to muscle damage • Urine is dark brown to black.

• Muscle damage

Glucose

Glucosuria

• Appears if blood glucose threshold is exceeded BG values • Canine: >180 mg/dL • Feline: >300 mg/dL • Not detectable in the urine of normal animals • False negatives: cold urine

• Diabetes mellitus, Cushing’s disease, chronic liver disease, high carbohydrate meal, stress, fear, restraint, administration of IV glucose, and Fanconi’s syndrome

Ketones

Ketonuria

• • • • • •

• Diabetes mellitus, liver disease, persistent fever, high-fat diets, starvation, fasting, and long-term anorexia

Formed from the breakdown of fatty acids Not detectable in the urine of normal animals Produces a sweet, fruity smell False-negative: delayed analysis False-positives: pigmented urine Confirmation tests: Acetest

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4

Table 4.25 / Chemistry Strip Examination (Continued) Chemical Property

Observation

Definition

Associated Conditions

pH

Normal

• Concentration of H+ ions, a measure of the degree of alkalinity or acidity • Canine: 5.2–6.8 • Feline: 6.0–7.0

• N/A

Alkaline

• ↑ Concentration of H+ ions • <7.0 • False-increases: delayed analysis

• Postprandial alkaline tide, plant diets, UTI, metabolic and/or respiratory alkalosis, distal renal tubular acidosis, urine retention, and certain drugs (e.g., bicarbonate, citrate)

Acidic

• ↓ Concentration of H+ ions • >7.0

• Protein diets, metabolic or respiratory acidosis, fever, starvation, excessive muscular activity, chloride depletion, and certain drugs (e.g., DL-methionine, furosemide)

Protein

Proteinuria

• Measurement of albumin and globulins • Only found in trace amounts in normal urine • Always interpret in light of USG and contents of urine sediment • False positives: ↑ USG, ↑ pH, pigmented urine, detergent contamination • Confirmation tests: sulfosalicyclic acid test, microalbuminuria test (e.g., Heska ERD screen)

• Glomerulonephritis, glomerular amyloidosis, multiple myeloma, parturition, estrus, and UTI

Protein : Creatinine Ratio

Normal

• Quantifies level of proteinuria as significant or not • Canine: ≤0.3 • Feline: ≤0.6

• N/A

Increased

• ↑ Urine protein loss • >1

• Chronic interstitial nephritis, glomerulonephritis, and amyloidosis

4

a

To differentiate between hemoglobinuria and myoglobinuria, compare plasma and urine simultaneously. Plasma and urine will both appear red with the presence of hemoglobin, and only urine will appear red to brown with myoglobin.

Sediment Examination A microscopic examination of the urine sediment should be a part of every routine urinalysis. It is used to confirm findings from gross examination and chemistry strip examination. Much additional information can be gained from a microscopic examination that cannot be determined in any other method. Samples collected first thing in the morning or after several hours of water deprivation provide the most diagnostic information. The increased concentration of these samples increases the likelihood of finding formed elements. Each laboratory needs to determine their normals and urine procedures. Commonly, a standard amount of 5 mL urine is centrifuged and poured off, leaving the pellet and approximately 0.3 mL urine in the tube. The remain150

SECTION THREE: DIAGNOSTIC SKILLS

ing urine and pellet are mixed together, and 1 drop is placed on a slide. A coverslip is placed over the drop, and the sample may be read either stained or unstained. When examining an unstained sample, achieving proper light adjustment (e.g., lower stage slightly or partially close diaphragm) of the microscope to view refractile elements is important. The entire slide is examined with low power to look for areas of cell clusters, casts, cellularity; paying attention to the periphery. Casts and crystals are evaluated at low power and reported as #/lpf (low-power field). RBCs, WBCs, and epithelial cells are examined with high power and reported as #/hpf (high-power field). Bacteria and sperm are examined under high power and reported as rare through 4.

Reporting of Bacteria and Sperm Rare—only a few seen after scanning numerous fields 1+: <1/hpf 2+: 1–5/hpf 3+: 6–20/hpf 4+: >20/hpf 4 Table 4.26 / Sediment Examination (See figures in Color Plate 15–22) Bacteria

Bacteria are not normally found in properly collected normal urine samples. Its presence with WBCs often indicates a bacterial infection, whereas the absence of WBCs typically indicates a contaminated sample. A sample properly collected via cystocentesis or catheterization should be sterile and any presence of bacteria is significant (e.g., diabetes mellitus, Cushing’s disease, and glucocorticoid treatment). See color plates 4.59 and 4.61. Note: Normal brownian movement may often be confused with bacteria in unstained sediments. Component

Appearance

Definition

Associated Conditions

Cocci

• Circular bacteria in singles, pairs, or chains • Refract light and have brownian movement • Confirm with gram stain of an air-dried smear of urine; cocci will be gram-positive • Difficult to detect if <100,000 bacteria/mL

• Acid pH: Enterococcus and Streptococcus spp. • Alkaline pH: Staphylococcus spp.

• UTI, cystitis, pyelonephritis, metritis, prostatitis, vaginitis

Bacilli

• Rod-shaped bacteria in singles, pairs, or chains • Refract light and have brownian movement • Difficult to detect if <10,000 bacteria/mL

• Acid pH: E. coli • Alkaline pH: Proteus spp.

• UTI, cystitis, pyelonephritis, metritis, prostatitis, vaginitis

Blood Cells Blood cells are classified by number per high power field (#/hpf). Blood cells are thought to always be significant unless reviewed against other factors affecting the animal. For example, an animal with only a few RBCs and no other abnormalities may have received trauma through a catheterization procedure. WBCs are always thought to be significant, because they typically only appear with some level of an infection, unless contamination of infected genitalia takes place. WBCs do not need to be classified into type; by the time they reach the bladder, they have degenerated to an unrecognizable state. The presence of WBCs should always result in an in-depth look for bacteria. RBCs • Color Plate 4.64 • Color Plate 4.69

• Smooth edges, small, and biconcave • Size: 6–7 μm • Unstained: pale, yellow to orange disks without nuclei • Stained: varying color from light pink to dark red • Crenated: ruffled edges and slightly darker • Lysed: colorless rings of varying size • Dilute urine may show larger, swollen and globular RBCs

• Normal: Voided: 0–8/hpf Catheter: 0–5/hpf Cystocentesis: 0–3/hpf • Atraumatic technique will produce the above numbers, multiple attempts may ↑ the number of RBCs

• Cystitis, neoplasia, calculi, inflammation, necrosis, trauma, bleeding disorder

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Table 4.26 / Sediment Examination (Continued) Component WBCs • Color • Color • Color • Color

Plate Plate Plate Plate

4.60 4.62 4.63 4.64

4

Appearance

Definition

Associated Conditions

• Round with granular appearance (distinct nuclei) • Size: 10–14 μm • WBCs size ↑ in dilute urine and ↓ in concentrated urine • Presence of WBCs should cause careful consideration for the presence of bacteria and culture setup

• Normal: Voided: 0–1/hpf • Neutrophils are the most common type of WBC seen

• Nephritis, pyelonephritis, cystitis, urethritis, ureteritis

Casts Casts, consisting of a mucoprotein matrix, are formed in the lumen of the distal and collecting tubules of the kidneys. Because of this location, they are all cylindrical with parallel sides and rounded to blunted ends. Cast morphology is susceptible to high-speed centrifugation, rough handling, and delayed analysis (degrade when allowed to sit in alkaline urine or for long periods). The presence of ↑ numbers of casts may indicate tubular disease, but the quantity does not suggest the duration or severity of disease. Epithelial • Color Plate 4.65

• Nearly transparent, clear, and highly refractile with renal epithelial cells

• Originate from the Loop of Henle, distal tubule and collecting tubule • Never observed in normal urine

• Nephrotoxicity, acute renal disease, ischemia, pyelonephritis

Fatty • Color Plate 4.66

• Coarsely granular with fat droplets

• Signify degeneration of the renal tubules

• Diabetes mellitus and renal disease

Granular • Color Plate 4.67

• Coarse to finely granular • Orange: bilirubin • Pink to red: hemoglobin or myoglobin

• Composed of particulate matter from renal tubular cell necrosis or degeneration • Hyaline casts containing granules • Normal to see 0–2/hpf

• Acute renal disease

Hyaline • Color Plate 4.68

• • • •

• Composed of pure protein precipitates (mucoprotein matrix) • Normal to see 0–2/hpf

• Fever, mild renal disease, general anesthesia, IV diuresis, strenuous exercise

RBC/WBC • Color Plate 4.69 • Color Plate 4.70

• RBC: • Contains a few to many RBCs • Deep yellow to orange • WBC: • Contains a few to many WBCs • Appearance changes to granular once the cells start to degenerate

• Formed from the aggregation of RBCs and/ or WBCs • Never observed in normal urine

• Intrarenal bleeding or infection, trauma, glomerulonephritis, renal tubulointerstitial inflammation, toxicity

Waxy • Color Plate 4.71

• Highly refractile, homogeneous, and translucent • Blunted ends and cracks

• Final stage of granular cast degeneration • Most stable of all casts

• Chronic renal disease

152

Nearly transparent, clear and highly refractile Rounded ends Stained: light pink to purple May contain a few inclusions

SECTION THREE: DIAGNOSTIC SKILLS

Table 4.26 / Sediment Examination (Continued) Component

Appearance

Definition

Associated Conditions

Crystals Crystalluria may or may not be indicative of a medical condition. Crystals may form because of sample handling (e.g., refrigeration) or through the accumulation of normal urine components. Urine pH, concentration, temperature, and solubility of the components all contributes to the type of crystal formed. Crystals can be reported as occasional, moderate, many or by using a 1–4+ scale. Amorphous Phosphate • Color Plate 4.59 • Color Plate 4.72

• Granular precipitate • Dull brown in color

• Typically seen in neutral or alkaline urine • Seen in normal urine • Easily confused with bacteria

• Liver disease, portosystemic shunts, or breed predisposed (Dalmatian and English Bulldog)

Amorphous Urate • Color Plate 4.73

• Granular precipitate (sodium, potassium, magnesium and calcium salts) • Yellow or yellow-brown in color

• Typically seen in acidic urine • Dissolve in alkaline urine • Easily confused with bacteria

• Liver disease, portosystemic shunts, or breed predisposed (Dalmatian and English Bulldog)

Ammonium Biurate • Color Plate 4.74

• Round with long spicules • Resemble a thorn apple • Yellow to brown in color

• Seen in alkaline, neutral or slightly acidic urine

• Liver disease, portosystemic shunts, urate urolithiasis, or breed predisposed (Dalmatian and English Bulldog)

Bilirubin • Color Plate 4.75

• Fine elongated spicules • Red brown or golden yellow in color

• May be seen in normal urine

• Liver disease or hemolytic anemia

Calcium Carbonate • Color Plate 4.76

• Round with lines radiating out from the center • May resemble short dumbbells

• Typically seen in alkaline urine

• N/A

Calcium Oxalate Dihydrate • Color Plate 4.77

• Colorless, square with refractile lines forming an × across the surface (e.g., envelopes) • Radiopaque with hard, sharp protrusions • +/− Cuboid shape

• Typically seen in neutral or acidic urine • May be seen in normal urine

• Ethylene glycol toxicity, oxalate urolithiasis

Calcium Oxalate Monohydrate

• Small, flat, elongated structures with pointed ends (e.g., spindles)

• Typically seen in neutral or acidic urine

• Ethylene glycol toxicity, oxalate urolithiasis

Cystine • Color Plate 4.78

• Hexagon and flat • May appear as singles or in layers

• Typically seen in acidic urine

• Renal tubular dysfunction

Leucine • Color Plate 4.79

• Yellow or brown, round with concentric striations

• Typically seen in acidic urine • Not well understood

• Acute liver disease or chloroform or phosphorus toxicity

Sulfonamide • Color Plate 4.80

• Clear to brown, eccentrically bound needles in sheaves

• Rarely seen with the newer forms of sulfonamide drugs

• Sulfonamide treatment

Triple Phosphate (Struvite, Magnesium, Ammonium and Phosphate, MAPS) • Color Plate 4.81

• 8-sided prisms with tapered sides and ends • Resemble coffin lids • ↑ Ammonia leads to fern leaf like appearance

• Typically seen in neutral or alkaline urine

• Cystitis or struvite urolithiasis

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4

Table 4.26 / Sediment Examination (Continued)

4

Component

Appearance

Definition

Associated Conditions

Tyrosine • Color Plate 4.82

• Colorless or yellow, very fine needles in sheaves or clusters

• Typically seen in acidic urine • Not well understood

• Acute liver disease or chloroform or phosphorus toxicity

Uric Acid • Color Plate 4.83

• Yellow brown diamond, rosettes, or oval plates with pointed ends

• Typically seen in acidic urine

• Liver disease, portosystemic shunts, or breed predisposed (Dalmatian and English Bulldog)

Epithelial Cells Squamous and transitional epithelial cells are seen commonly in the urine of normal animals. Squamous epithelial cells are the largest of the epithelial cells and are considered not significant. Transitional epithelial cells only prove to be significant with a large increase in number. Renal epithelial cells, however, are typically only seen with renal disease and always thought to be significant. They are the smallest of the epithelial cells and are often confused with WBCs. Renal • Color Plate 4.84

• Round to caudate with a large eccentric nucleus displaced near the bottom • Prominent nucleolus • Often confused with WBCs

• Epithelial cells originating from the renal tubules • Rarely found and usually indicate renal disease

• Renal disease

Squamous • Color Plate 4.85

• Very large, thin, and polygonal • Tend to fold onto themselves and appear singularly or in sheets • Small, round nucleus, placed close to the center • Appears as a fried egg

• Epithelial cells originating from the urethra, bladder, vagina, and prepuce • Often seen and typically not significant

• N/A

Transitional • Color Plate 4.86

• Round to caudate, granular with a small nucleus centrally located • Varying size

• Epithelial cells originating from the prokimal urethra, bladder, ureters, and renal pelvis • Often seen and only significant in large numbers, clumps or sheets

• Cystitis, pyelonephritis, or neoplasia

Miscellaneous Numerous artifacts can be seen in urine because of contamination. The following also can be seen with a disease condition associated with the urinary tract. Hemoglobin

• Orange globules with varying size

• Intravascular hemolysis resulting in free hemoglobin • Often confused with RBCs

• Severe hemolytic diseases or alkaline urine

Lipid Droplets • Color Plate 4.87

• Varying size, round, light green, and highly refractile • Seen in the plane of field just below the coverslip

• Commonly seen in urine associated with no disease condition • Often confused with RBCs

• Diabetes mellitus, obesity, and hypothyroidism

Mucus Threads

• Resemble twisting ribbons

• More commonly seen after catheterization • May be seen in normal animals

• Urethral irritation or genital

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Table 4.26 / Sediment Examination (Continued) Component

Appearance

Definition

Associated Conditions

Parasites Two urinary tract parasites can be seen in the dog and cat. Fecal contamination may lead to finding an array of parasites in urine, but the following are the only ones that originate from the bladder. Capillaria Plica • Color Plate 4.88

• Clear to yellow with flattened bipolar end plugs and a roughened shell

• Bladder worm of dogs and cats • Travels through the lungs and may cause coughing

• Nonpathogenic

Dioctophyma Renale

• Barrel shaped, bipolar, yellow brown with a pitted shell

• Giant kidney worm of the dog • Largest nematode affecting domestic animals • Ingest the parenchyma of the right kidney, leaving only the capsule • Crayfish and fish are the intermediate host.

• Kidney disease or peritonitis

Urine Artifacts Many substances can contaminate a urine sample. They may arise from improper collection, the environment, or general anatomy. Besides the arti-

4

facts listed below, parasite eggs, fecal material, fungal spores, and fungi also may be seen. Please refer to the respective sections for identification of these items.

Table 4.27 / Urine Artifacts Urine Artifact

Appearance

Definition

Air Bubbles • Color Plate 4.78

• Varying size, round, flat, refractile with a dark border

• Result from the trapping of air during the application of the cover slip

Fungi

• Aseptae or segmented hyphae

• Contaminant • Patients with systemic fungal disease affecting the urinary system (rare)

Hair

• Needle like with tapered edges

• Contaminant from environment or surrounding genitalia

Pollen

• Double budding spores (e.g., Mickey Mouse®)

• Contaminant from environment

Sperm

• Oval head with a whip like tail

• Seen in the urine of intact males or recently mated females

Starch Granules • Color Plate 4.89

• Faceted or scallop edges with indented or dimpled center • Not refractile

• Contaminant from gloves

Yeast • Color Plate 4.90

• Oblong, colorless budding bodies with double refractile walls • Varying size

• Contaminant from environment or surrounding genitalia • Certain species may infect the urinary tract of patients with resistant UTI (rare)

Note: The normal values for this chapter are used with permission from Phoenix Central Laboratory.

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Chapter

5

Imaging Radiology 159 Radiographic Equipment 160 Radiographic Exposure and Image Factors 161 Radiographic Technique Chart 161 Example 1: Veterinary X-Ray Technique Guide 162 Example 2: Veterinary X-Ray Technique Chart 163 Evaluating Radiograph Technique 164 Exposure Evaluation 164 Density Evaluation 164 Scale of Contrast Evaluation 164 Radiographic Alterations 166 Radiographic Artifacts 167 Radiographic Positioning 167 Directional Terms 168 Positional Terms 168 Soft Tissue Positioning 169 Thorax 169 Abdomen and Pharynx 169 Head Positioning 170 Skull 170 Zygomatic Arch 171

Tympanic Bullae 172 Temporomandibular Joint 172 Nasal Cavities and Sinuses 173 Nasal Cavities and Sinuses (continued) Spine Positioning 174 Cervical 174 Thoracic–Lumbar 175 Sacrum–Caudal 175 Shoulder and Forelimb Positioning 176 Scapula–Shoulder 176 Humerus 176 Elbow 177 Radius/Ulna and Carpus 178 Metacarpus/Phalanges 178 Pelvis and Hindlimb Positioning 179 Pelvis 179 Femur, Stifles, and Tibia/Fibula 180 Tarsus and Metatarsals 181 Radiographic Contrast Studies 181 Types of Contrast Media 182 Fistula Contrast Studies 183

5

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Fistulography 183 Abdominal Contrast Studies 183 Peritoneography 183 Gastrointestinal Tract Contrast Studies 184 Esophagography and Gastrography 184 Upper and Lower Gastrointestinal Study 185 Head Contrast Studies 187 Dacryocystorhinography, Rhinography, and Sialography 187 Spinal and Joint Contrast Studies 188 Myelography and Epidurography 188 Discography and Arthrography 189 Urethra Contrast Studies 190 Urethrography, Canine 190

5

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Urethrography, Feline 191 Vaginal Contrast Studies 192 Vaginography 192 Urinary Tract Contrast Studies 193 Cystography 193 Cystography (continued) 194 Additional Imaging Techniques 195 Computer Tomography and Echocardiography 195 Fluoroscopy 196 Magnetic Resonance Imaging and Nuclear Medicine Ultrasonography 197 Basic Scanning Technique 198 Sites for Ultrasound Scanning 198

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a

Key Words and Termsa

Abbreviations

Collimate Commissure Computer radiography Contrast Density Dosimeter Hypertonic Manubrium Mucoceles Radiolucent Radiopaque Retrograde Santes’ rule Stranguria Transaxially

C, cranial Cd, caudal CHF, congestive heart failure CMIARF, contrast medium–induced acute renal failure CRT, capillary refill time CSF, cerebral spinal fluid CT, computed tomography D, dorsal Di, distal DR, digital radiography DV, dorsoventral EU, excretory urography FFD, focal film distance GIT, gastrointestinal tract IP, image plate IVP, intravenous pyelography IVU, intravenous urography kVp, kilovoltage peak

Additional Resources, page L, lateral LAT, lateral M, medial mA, milliamperage mA-s, milliamperage per second MHz, megahertz MM, mucous membranes MRI, magnetic resonance imaging OBL, oblique Pa, palmar Pl, plantar Pr, proxmial R, rostral s, seconds SID, source image distance V, ventral VD, ventrodorsal

Anatomy, 3 Anesthesia, 439 Catheter Placement, 349 Fluid Therapy, 359 General Medicine, 201 Injections, 348 Medical Procedures, 427 Monitoring, 332 Stomach Tube Placement, 428 Urinary Catheter Placement, 435

5

Key words and terms are defined in the glossary on page 631

RADIOLOGY Radiographs are an extremely useful diagnostic tool for the veterinarian. However, to be diagnostic, the radiograph must reflect proper measurement and positioning of the patient. Veterinary technicians are a valuable resource in the production of these radiographs. An understanding of the anatomic layout of the species and the manner in which a radiograph is taken is of great assistance to the production of a diagnostic radiograph. This chapter contains the basic information of radiographic equipment, imaging factors, positioning information, and contrast radiography.

Digital radiography (DR) has made its way into the veterinary field. This technology complements the advancements made in computer technology and results in many benefits for the patient, veterinarian, and staff. The advantages to DR include increased time efficiency in processing, storing and retrieving of radiographs, improved contrast resolution allowing soft tissue and bone evaluation in one image, and the ability to use teleradiology. There is also the ability to change the contrast and density of the image to improve diagnostic sensitivity, but this technique can also add artifacts leading to confusion and misdiagnosis. With the expected decrease in the number of retakes due to computer manipulation and the increased efficiency of the DR unit, patient and staff safety should increase.

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Table 5.1 / Radiographic Equipment

Radiographic equipment is especially expensive and extreme care should be taken with its use and maintenance. However, the greatest risk with radiography is patient and staff safety. It has been scientifically proven that ionizing radiation causes damage to living cells (e.g., reproductive, growth, gonadal, cancer, metabolically active cells). There is no level of exposure that is nondamaging; therefore, caution should be taken to limit exposure to the lowest level possible. Protective apparel is the first defense against radiation exposure—lead aprons, thyroid shields, and gloves must be worn in all circumstances. The staff should also protect themselves by wearing a dosimeter badge and goggles and by staying as far back from the primary beam and subsequent scatter radiation as possible. Excessive and unnecessary exposure should also be avoided. Equipment

Description

Maintenance

Protective Apparel

• • • •

• Hang aprons vertically or lay flat. • Gloves should be placed on vertical holders or over bottomless soup cans to allow airflow and avoid cracks in the lead lining. • Radiograph all apparel quarterly to assess protectiveness of shield and check for cracks, tears, or other irregularities.

5

Aprons Thyroid shields Gloves Dosimeter

Film-Screen Radiography Processing Tanks

• Develops the film • May be manual or automatic

• Clean routinely, and replenish liquids as needed. • Clean thoroughly every 2–3 months. • Check manufacturer’s guidelines for your specific machine.

Film

• Imprints the image (various types)

• Handle carefully. • Store in a vertical position in a cool, dry, dark place.

Cassettes

• Houses the film and intensifying screens

• Do not drop or allow leaking liquids into the cassette. • Clean the exterior regularly with mild soap and water. • Clean the intensifying screens routinely with a commercial solution, mild soap and water, or dilute ethyl alcohol. • Leave the cassette open and propped in a vertical position to dry. • Store in a vertical position when loaded with film.

Computed Radiography Reader

• Reads the image from the IP

Image Plate (IP)

• Imprints the image

Computer

• Manipulates and permits viewing of the image

• Erase the plates daily. • Clean the plates once a week.

Direct Digital Radiography Selenium Detector Plate

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c05.indd 160

• Utilizes a direct energy conversion process to capture image

• Offset calibration daily.

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Table 5.2 / Radiographic Exposure and Image Factors Factor

Definition

Application

Contrast

• The difference between the lightest and darkest part of the film, reflecting 2 adjacent radiographic densities

• High kVp (low contrast) for tissue • Low kVp (high contrast) for bone

Density

• The degree of blackness of a film

• To produce a darker film ↑ mA, kVp, or exposure time

Detail

• The clarity of the image on the film

• For better detail: use longer source–image distance (SID), have the patient closer to the film, and use a shorter exposure time.

Distortion

• The alteration of the original image

• For less distortion: use short SID, have the patient closer to the film, and less angulation of the film or patient.

Exposure Time (s)

• Measures the length of time electrons are allowed to flow across the tube

• Longer exposure time = ↑ production of x-rays • mA-s is the product of milliamperage and the exposure time. It indicates the number of x-rays being produced during an exposure. • Using a high mA setting allows for the use of shorter exposure times.

Grid Factor

• The ↑ in exposure to compensate absorption by the grid device

• Used in the formation of a technique chart (part of Santes’ rule)

Kilovoltage peak (kVp)

• Measurement of the electric potential difference between the cathode and anode in the x-ray tube

• Higher kVp = greater penetration power • Controls the quality • Directly proportional to film density and inversely proportional to film contrast

Milliamperage (mA)

• Measurement of the number of electrons that flow across the tube from cathode to anode

• Higher mA = production of more x-rays • Directly proportional to film density

Milliamperage per Second (mA-s)

• The number of x-rays produced per second

• Controls the number and quantity of x-rays produced

Source Image Distance (SID) • Focal spot to film distance (FFD)

• The distance between the focal spot on the target anode and the radiographic film

• ↑ SID = a ↓ in the number of x-rays reaching the film

Radiographic Technique Chart Every clinic with an x-ray machine should have a technique chart that has been assessed by the local radiologist to fit your particular machine. These charts significantly decrease the time involved in the calculation of the machine settings and thereby reduce the time spent on taking each radiograph. The chart also ensures consistency among the personnel using the machine. Factors involved in a technique chart are the species, the anatomic region, the x-ray machine, screen type, and the film type. The basic steps to set up a technique chart are:

1. Choose an animal of respective size to reflect its species (e.g., canine: an animal around 50 pounds; feline: an animal around 9 pounds). 2. Measure the animal laterally around the thickest part of the thorax. Set standard SID as a constant (40). 3. Calculate the kVp requirement using Santes’ rule: (2 × tissue thickness in cm) + SID + grid factor = kVp. • Example: (2 × 15 cm) + 40 + 8 = 78 kVp 4. Determine mA-s requirement based on the following chart: CHAPTER 5 / IMAGING

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Fast/High-Speed Screens

Average Dog

Medium/Par Speed Screens

MA-s

Anatomical Region

mA-s

2.5

Extremity

5.0

5.0

Thorax

7.5

7.5

Abdomen

10.0

10.0

Pelvis

12.5

Average cat: mA-s is recommended at 1.5. 5 5. Determine the mA and exposure time with emphasis on the highest mA possible. Divide mA by mA-s to get exposure time (seconds). 1 Example: 300 divided by 5.0 = –60

6. Take a trial radiograph of the animal, using the calculated factors and assess its quality. Modify the mA-s by 30–50% in the appropriate direction and retake the radiograph. 7. Once a diagnostic radiograph is produced, use these factor numbers to start your chart. This will need to be repeated for the various areas of the body and for each species. See guidelines below for the chart making: For each 1-cm change, add or subtract 2 kVp, up to 80 kVp. For each 1-cm change, add or subtract 3 kVp, from 80–100 kVp. For each 1-cm change, add or subtract 4 kVp, above 100 kVp. 8. Modifications to this method would include: a. Pleural fluid or ascites or obvious organ enlargement (e.g., cardiomegaly) (↑ mA-s 50%) b. Obesity, heavily muscled dogs, or contrast studies (↑ mA-s 50%) c. Excessively thin animals or puppies/kittens (↓ mA-s by 50%) The following charts reflect 2 different styles of a technique chart. It is helpful to have your chart reviewed by a board-certified radiologist.

Example 1: Veterinary X-Ray Technique Chart The following is for use with: QUANTA 3 screens SID is 40″. Grid ratio is 8:1 CRONEX 7 film Kodak LANEX REGULAR Kodak TMG-1 film mA

Time

mA-s

kVp

Skull 3.3

(2 × cm) + 55 kVp

1/60

5

(2 × cm) + 55 kVp

300

1/60

5

(2 × cm) + 50 kVp

300

1/30

10

(2 × cm) + 48 kVp

Small Dogs and Cats

300

Medium and Large Dogs

300

Small Dogs and Cats Medium and Large Dogs

Cervical

Thorax 3.3

(2 × cm) + 43 kVp

1/60

5

(2 × cm) + 43 kVp

300

1/60

5

(2 × cm) + 45 kVp

300

1/30

10

(2 × cm) + 50 kVp

Small Dogs and Cats

300

1/60

5

(2 × cm) + 52 kVp

Medium and Large Dogs

300

1/30

10

(2 × cm) + 52 kVp

Extra-Large Dogs

300

1/30

10

(2 × cm) + 60 kVp

Small Dogs and Cats

300

Medium and Large Dogs

300

Small Dogs and Cats Medium and Large Dogs

Abdomen and Thoracic Spine

Pelvis

Extremities: Femur and Humerus Small Dogs and Cats

300

1/45

Medium and Large Dogs

300

1/30

Small Dogs and Cats

300

1/45

Medium and Large Dogs

300

1/30

6.6 10

(2 × cm) + 45 kVp (2 × cm) + 45 kVp

Extremities: Radius and Ulna

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6.6 10

(2 × cm) + 45 kVp (2 × cm) + 45 kVp

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Example 2: Veterinary X-Ray Technique Chart Bone 300 mA

Chest 300 mA kVp

Abdomen 300 mA kVp

kVp

cm

Time

Table

Grid

Time

Table

Grid

Time

Table

Grid

4

1/30

42

—

1/60

44

—

1/30

—

—

5

“

“

—

“

46

—

“

—

—

6

“

45

—

“

48

—

“

—

—

7

“

“

55

“

50

—

“

—

—

8

“

“

57

“

52

—

1/15

—

51

9

“

46

59

“

54

—

“

—

53

10

“

“

61

“

56

—

“

—

55

11

“

—

63

“

58

—

“

—

57

12

“

—

65

“

60

74

“

—

59

13

“

—

67

“

62

76

“

—

61

14

“

—

69

“

64

78

“

—

63

15

“

—

71

“

66

80

“

—

65

16

“

—

73

“

68

82

“

—

67

17

“

—

75

“

—

85

“

—

69

18

“

—

77

“

—

88

“

—

71

19

“

—

79

“

—

91

“

—

73

20

“

—

81

“

—

95

“

—

75

21

“

—

84

“

—

99

“

—

77

22

“

—

87

“

—

103

“

—

79

23

“

—

90

“

—

103

“

—

82

24

“

—

94

1/30

—

96

“

—

85

25

“

—

96

“

—

100

“

—

88

26

“

—

103

“

—

105

“

—

91

27

“

—

108

“

—

110

“

—

95

5

“ Indicates same value as above; —, not applicable.

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Evaluating Radiograph Technique

Density Evaluation

Following a technique chart to take a radiograph is a straightforward process. However, this still may not produce a radiograph with the contrast and density needed for a quality image. There are many factors that affect the quality of the film; besides equipment issues, the mA, kVp, and time have considerable control of image quality. Understanding their relationship along with the difference based on BCS, breed, and disease condition can produce the desired quality of radiograph.

The density of a film is the degree of blackness and is mostly controlled by mA-s. Begin evaluating the density by determining the degree of blackness. The area outside the patient’s body and inside the collimated area should be black. Lighter shades would indicate ↑ density is needed.

Table 5.3 / Exposure Evaluation

5

To determine if an x-ray needs to be adjusted, one must first be able to evaluate the quality of a film. There are some basic guidelines to a properly exposed image, but there is also veterinarian preference. Begin by evaluating the overall appearance (e.g., too light or too dark) of the x-ray. With the xray on a standard viewing box, place your hand under the image. If you are able to see your fingers, yet not the wrinkles and creases the image has the correct exposure. If you are not able to see your fingers, the image is overexposed (too dark) and if you can see your fingers and all wrinkles and creases the image is underexposed (too light). If it is determined that an image is too light or too dark, further evaluations need to take place to determine why. Underexposed (Too Light)

Good Exposure

Overexposed (Too Dark)

Hand Test

• Fingers, wrinkles, and creases visible

• Fingers visible

• Fingers not visible

Thorax

• Visible: surrounding vasculature • Not visible: vasculature over the heart, lung over diaphragm

• Visible: caudal vena cava, descending aorta, bronchi, pulmonary vessels, cardiac silhouette, air-filled lungs • Taken on inspiration • Optimal: high kVp and low mA-s (↑ contrast and ↓ density)

• Lungs are as black as the background.

Abdomen

• Internal organs are washed out and not distinguishable.

• Visible: margins of the internal organs, stomach, diaphragm, small and large intestines, liver, spleen, bladder, ± kidneys, prostate • Taken on expiration • Optimal: low kVp and high mA-s (↑ density and ↑ contrast)

• Internal organs are dark and not distinguishable.

• Clear margins of compact bone with a radiolucent center, physes in young animals (can be open up to 14 months) • Optimal: low kVp and high mA-s (↑ density and ↑ contrast)

• Bone is bright white with no detail.

Bony Structures • Bone is dark with no detail. Eraluating Radiograph Technique Table 5.4 / Scale of Contrast Evaluation

The scale of contrast is the shades of grays or the degree of blacks and whites and is mostly controlled by kVp. A kVp setting that is too high will give a low contrast (e.g., overall gray appearance). A kVp setting that is too low will give a high contrast (e.g., strong blacks and whites). Once a radiograph has been evaluated and it is determined that alterations are needed, the decision needs to be made as to what settings need to be altered. Unfortunately, this is not an exact science and adjustments of one or more settings may be needed. However, there are some general starting points when adjusting the settings. In general, mA-s is altered by 25–50% to make large overall changes and to alter the density (degree of blackness). kVp is altered by 10–15% to make small subtle changes and alter the scale of contrast. Another point, altering the kVp by 10–15% is approximately the same change in exposure as altering the mA-s by 50% (e.g., halving or doubling the mA-s). Therefore, with proper exposure and the need to only change the contrast, the kVp and mA-s must be altered together in the opposite direction (e.g., ↑ kVp and ↓ mA-s). 164

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Table 5.4 / Scale of Contrast Evaluation (Continued) Alteration

↑ Density • Film is too dark.

• ↓ mA-s • To ↓ the amount of x-rays and ↓ the blackness

↓ Density • Film is too light.

• ↑ mA-s • To ↑ the amount of x-rays and ↑ the blackness

↑ Contrast • Film has strong blacks and whites.

• ↑ kVp • To ↑ the penetrating power of the x-rays and to lengthen the scale of contrast

↓ Contrast • Film is washed out/gray appearance.

• ↓ kVp • To ↓ the penetrating power of the x-rays and to shorten the scale of contrast

Example

5

Film

Evaluation

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Table 5.5 / Radiographic Alterations

BCS

With radiology experience, adjustments to the mA-s and kVp can be made prior to the first x-ray taken. There are certain anatomical factors (e.g., body weight, muscle mass, haircoat) that are known to alter the image based on the technique chart. The technique chart is based on an “average” animal and alteration for normal often requires setting adjustments. The most important point to remember is that large changes are made with mA-s (25–50%) and subtle changes are made with kVp (10–15%).

Disease

Breed and Anatomy

5

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Evaluation

Radiograph Effect

Setting Alteration

Comments

BCS 1–2

• ↓ Body fat, muscle wasting

• ↓ mA-s and/or kVp

• ↓ Subject density

BCS 4–5

• ↑ Body fat

• ↑ mA-s and/or kVp

• ↑ Subject density

Achondroplastic dwarf

• Compressed mediastinal area • Short dense legs

• ↑ mA-s and/or kVp

• ↑ Subject density • Be sure legs are pulled out of the view (e.g., tape stirrups).

Barrel-chested

• ↑ Thoracic size

• ↑ mA-s

• ↑ Subject density • Extend cervical region as far forward as possible.

Brachycephalics

• Motion artifact • Trapped air • X-rays not taken on inspiration/expiration

• ↓ mA-s and/or kVp to ↓ density

• Blow in their nose to briefly stop panting.

Deep-chested

• Deep cranial thorax and thin caudal thorax

• ↓ mA-s and/or kVp

• Two views may need to be taken to achieve proper exposure in both regions. • Ensure proper positioning of VD images (e.g., supportive devices) to avoid oblique images.

Giant breeds

• ↑ Overall size

• ↑ mA-s

• ↑ Subject density • Divide the area into 2 sections (e.g., cranial and caudal thorax) to view entire area.

Haircoat

• Excessive amount or mats • Debris and foreign bodies

• ↑ kVp

• ↑ Subject density • Move excessive hair out of view if possible. • Foreign bodies found on the image should be verified they are not within the haircoat.

Muscle

• ↑ Muscle mass

• ↑ mA-s and/or kVp

• ↑ Subject density • Ensure proper positioning of VD images (e.g., supportive devices) to avoid oblique images.

Skin

• ↑ Skin folds

• ↑ mA-s and/or kVp

• ↑ Subject density • Pull skin folds out of view if possible.

Any condition resulting in:

• Ascites/edema

• ↑ mA-s and ± ↓ kVp

• ↑ kVp along with free fluid = ↑ scatter

• Free air

• ↓ mA-s and/or kVp

• ↓ Subject density

• Foreign bodies

• ± mA-s and kVp alterations

• Adjustments are made based on the opacity of the item.

• Soft tissue swelling

• ↑ mA-s and/or kVp

• ↑ Subject density

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Table 5.6 / Radiographic Artifacts Problems Seen on Radiograph

Artifact

Solution

Blurred images

• Motion • Double exposure

• Proper positioning and handling of animal • Double-check cassette tray for foreign objects

Clear areas on the sides of the radiograph

• Film fog • Mislocation of beam to film

• Proper handling of film • Verification that the beam and cassette are aligned

Dark line with mirror image of object

• Film folded on itself

• Proper loading of cassette

Dark semicircle impression

• Finger pressure mark

• Proper handling of film

Dark striations (sea lichen or dotted)

• Static electricity

• Proper handling of film

Gray streaks

• Wet animal fur

• Clean off and dry animal

Lines or objects visualized outside/inside the animal’s body that are unexplainable

• Foreign objects in or on the cassette (hair, paper, etc.)

• Proper cleaning of cassette • Proper handling of film

Hardwood flooring

• Plank floor

• ↓ mA-s

White lines across the film

• Scratches on the film

• Proper handling of film

Radiographic Positioning The most important factor in positioning a patient for radiographs is to have a mental vision of the part of the body to be radiographed and a good understanding of its anatomic placement. A second important factor is to use supports to ensure that the patient is aligned properly and to decrease the operator’s exposure. These supports can include sandbags,

5

nonradiopaque wedges, nonradiopaque “V” troughs, gauze, and tape. Depending on the species, size, and condition of the animal being radiographed, the following positioning guidelines may need to be adjusted accordingly. Understanding directional terminology is critical to the proper positioning of every radiograph. Specific anatomical landmarks are identified in Chapter 1: Anatomy.

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Table 5.7 / Directional Terms

5

Directional Term

Definition

Dorsal (D)

• Any given point toward the back

Ventral (V)

• Any given point toward the lower area of the thorax and abdomen, closest to the ground

Cranial (C)

• Any given point toward the head • The area above the carpal and tarsal joints on the limbs toward the head

Caudal (Cd)

• Any given point toward the tail • The area above the carpal and tarsal joints on the limbs toward the tail

Rostral (R)

• Any given point on the head toward the nose

Proximal (Pr)

• Any given point nearest the point of origin or attachment

Distal (Di)

• Any given point farthest away from the point of origin or attachment

Medial (M)

• An area near the midline • The inside aspect of the limbs

Lateral (L, Lat)

• An area situated away form or opposite the midline • The outside aspect of the limbs

Palmar (Pa)

• Caudal portion of the forelimb distal to the carpal joint

Plantar (Pl)

• Caudal portion of the hindlimb distal to the tarsal joint

Positioning Terms The patient is positioned so as the x-ray beam enters and exits based on the positional term. For example: caudocranial allows the x-ray beam to enter in the caudal aspect and exit the cranial aspect of a given anatomical region.

Dorsalventral (DV) Ventrodorsal (VD) Dorsopalmar (DPa) Palmarodorsal (PaD) Dorsoplantar (DPl) Plantarodorsal (PlD)

Additional Examples:

Recumbent: The patient is positioned on their side, left or right.

Caudocranial (CdC) Craniocaudal (CCd)

Oblique (Obl): The patient is placed in a slanted or inclined position so that the x-ray beam will enter the body at an angle.

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Soft Tissue Positioning Skill Box 5.1 / Soft Tissue Positioning: Thorax Anatomic Area

Thorax

View

Lateral

V/D

D/V

Positioning

• • • •

• Dorsal recumbency • Forelimbs extended cranially • Hindlimbs flexed

• Sternal recumbency • Forelimbs extended caudally and elbows abducted • Head lies low between forelimbs • Rear limbs in crouching position

Left lateral recumbency (heart assessment) Right lateral recumbency (lung assessment) Forelimbs and head extended cranially Rear limbs extended caudally

Measurement

• Widest area of ribcage

• Widest area of ribcage

• Widest area of ribcage

Beam Center

• Caudal border of scapula

• Caudal border of scapula (6th rib)

• Caudal border of scapula (6th rib)

Field of View

• Thoracic inlet to the last rib

• Thoracic inlet to the last rib

• Thoracic inlet to the last rib

Notes

• Taken on peak inspiration • If pneumothorax is suspected, expiratory radiographs also may be required. • May require support (e.g., wedges) to keep sternum inline with the thoracic vertebrae

• Taken on peak inspiration • If pneumothorax is suspected, expiratory radiographs also may be required. • Restraining the animal at the scapula/armpits results in a straighter thorax.

• Taken on peak inspiration • If pneumothorax is suspected, expiratory radiographs also may be required. • Preferred view for cardiac evaluation or for animal in respiratory stress

5

Skill Box 5.2 / Soft Tissue Positioning: Abdomen and Pharynx Anatomic Area

Abdomen

Pharynx

View

Lateral

V/D

Lateral

Positioning

• Right lateral recumbency • Forelimbs extended cranially • Hindlimbs extended caudally

• Dorsal recumbency • Forelimbs extended cranially and parallel

• Lateral recumbency • Forelimbs flexed caudally • Head should be parallel to the table (may require support) and neck extended.

Measurement

• Caudal aspect of the 13th rib or widest area

• Hindlimbs extended caudally and parallel

• Base of the skull

Beam Center

• Caudal aspect of the 13th rib

• Caudal aspect of the 13th rib or widest area

• Just caudal the base of the skull

Field of View

• 2–3 inches cranial to xyphoid process of sternum to the femoral head

• Caudal aspect of the 13th rib

• Lateral canthus to C3

Notes

• Taken on expiratory pause • A left lateral may also be requested. • Two films may be needed with large dogs.

• Taken on expiratory pause • Two films may be needed with large dogs.

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Head Positioning Ensuring that the skull is level to the cassette is extremely important in producing a diagnostic radiograph. Supports strategically placed under the muzzle, neck, or cranium will assist.

Skill Box 5.3 / Head Positioning: Skull 5

Anatomic Area

Skull

View

Lateral

D/V

V/D

Cranium—Rostrocaudal

Positioning

• Lateral recumbency • Foam wedge placed under mandible to make muzzle parallel • Nasal septum parallel to cassette • Forelimbs extended caudally

• Sternal recumbency • Head is parallel to the cassette. • Forelimbs are relaxed with carpus flexed and out of the beam.

• Dorsal recumbency • Head is extended on cassette with support under the mid-cervical region to keep proper alignment. • Nose is parallel to cassette. • Skull is level on the cassette. • Forelimbs extended caudally

• Dorsal recumbency • Base of skull is resting on cassette with neck in a flexed position and the chin pulled toward the thorax with tape or gauze. • Forelimbs extended caudally

Measurement

• Highest point of zygomatic arch

• Widest point of cranium

• Lateral canthus of eye

• Frontal sinuses

Beam Center

• Lateral canthus of eye

• Lateral canthus of eye

• Lateral canthus of eye

• Between the eyes

Field of View

• Tip of nose to base of skull

• Tip of nose to base of skull

• Tip of nose to base of skull

• Entire cranium

Notes

• May require heavy sedation or general anesthesia

• May require heavy sedation or general anesthesia

• May require heavy sedation or general anesthesia

• May require heavy sedation or general anesthesia • Monitor for crimping if endotracheal tube is in place.

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Skill Box 5.4 / Head Positioning: Zygomatic Arch Anatomic Area

Zygomatic Arch

View

Lateral

D/V

Frontal

Lateral Oblique

V/D Open Mouth

Positioning

• Lateral recumbency • Foam wedge placed under mandible • Nasal septum parallel to cassette • Forelimbs extended caudally

• Sternal recumbency • Head is resting on the cassette. • Forelimbs are relaxed with carpus flexed and out of the beam.

• Dorsal recumbency • Head is resting on cassette with neck in a relaxed flexed position. • Nose is slightly off perpendicular to x-ray beam. • Skull is level on the cassette. • Forelimbs extended caudally

• Lateral recumbency • Cranium supported with wedge to achieve the oblique angle of the arch • Nasal septum perpendicular to cassette

• Dorsal recumbency • Head is extended with support under the midcervical region. • Mandible supported open using gauze • Skull is level on the cassette. • Forelimbs extended caudally

Measurement

• Highest point of zygomatic arch

• Highest point of cranium

• Lateral canthus of eye

• Highest point of cranium

• Lateral canthus of eye

Beam Center

• Lateral canthus of eye

• Lateral canthus of eye

• Lateral canthus of eye

• Slight off center from mid-cranium

• At a 45° angle to the maxilla between the upper 3rd and 4th premolars

Field of View

• Tip of nose to base of skull

• Tip of nose to base of skull

• Tip of nose to base of skull

• Tip of nose to base of skull

• Nasal cavities to cranial temporal skull

Notes

• May require heavy sedation or general anesthesia

• May require heavy sedation or general anesthesia

• May require heavy sedation or general anesthesia

• May require heavy sedation or general anesthesia

• Monitor for crimping if endotracheal tube is in place.

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Skill Box 5.5 / Head Positioning: Tympanic Bullae Anatomic Area

5

Tympanic Bullae

View

D/V

Lateral Oblique

Rostrocaudal: Open Mouth

Positioning

• Sternal recumbency • Head is resting on the cassette. • Forelimbs are relaxed with carpus flexed and out of the beam.

• • • •

• Dorsal recumbency • Nose is perpendicular to cassette with maxilla and mandible supported open. • Base of skull is level on the cassette. • Forelimbs extended caudally

Measurement

• Highest point of cranium

• Level of tympanic bullae

• Level of commissure of lips

Beam Center

• Center of tympanic bullae

• Center of tympanic bullae

• Center of mouth and between commissure of lips

Field of View

• Lateral canthus of eye to base of skull

• Lateral canthus of eye to base of skull

• Entire nasopharyngeal area

Notes

• Superimposition of cranium makes view of bullae less than ideal; however, it permits comparison of left and right bullae in 1 view.

Lateral recumbency Unaffected bullae toward the cassette Skull slightly oblique Forelimbs slightly extended caudally

Skill Box 5.6 / Head Positioning: Temporomandibular Joint Anatomic Area

Temporomandibular Joint

View

D/V

V/D Oblique (Sagittal Oblique)

Positioning

• Sternal recumbency • Head is resting on the cassette. • Forelimbs are relaxed with carpus flexed and out of the beam.

• Lateral recumbency • Cranium rotated 20° toward the cassette (with support under mandible)

Measurement

• Highest point of cranium

• Lateral canthus of eye

Beam Center

• Lateral canthus of eye

• Temporomandibular joint

Field of View

• Base of the nose to the base of the skull

• Medial canthus of eye to base of skull

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Skill Box 5.7 / Head Positioning: Nasal Cavities and Sinuses Anatomic Area

Nasal Cavities and Sinuses

View

Lateral

D/V

D/V: Occlusal

Positioning

• Lateral recumbency • Foam wedge placed under mandible to keep muzzle parallel to cassette • Nasal septum parallel to cassette • Forelimbs extended caudally

• Sternal recumbency • Head is resting on the cassette. • Forelimbs are relaxed with carpus flexed and out of the beam.

• • • •

Measurement

• Highest point of zygomatic arch

• Highest point of cranium

• Caudal portion of maxilla

Beam Center

• Lateral canthus of eye

• Lateral canthus of eye

• Caudal portion of maxilla

Field of View

• Tip of nose to base of skull

• Tip of nose to commissure of lips

• Tip of nose to orbital bones

Notes

Sternal recumbency Head is resting on the cassette. Film is between maxilla and mandible. Forelimbs are relaxed with carpus flexed and out of the beam.

5

• Best to use “cassette-less” film (e.g., mammography film)

Skill Box 5.8 / Head Positioning: Nasal Cavities and Sinuses (continued) Anatomic Area

Nasal Cavities and Sinuses

View

V/D Open Mouth

Lateral Oblique

Frontal or Rostrocaudal

Positioning

• Dorsal recumbency • Forelimbs extended caudally • Head is extended on cassette with support under the mid-cervical region. • Nose is parallel to cassette with mandible extended caudally with supports. • Maxilla may be taped into position if necessary. • Skull is level on the cassette.

• Lateral recumbency • Head supported with wedge • Nasal septum perpendicular to cassette

• Dorsal recumbency • Forelimbs extended caudally • Head is resting on cassette with neck in a relaxed flexed position and muzzle pointing up at the tube. • Nose is slightly off perpendicular to cassette (10°). • Skull is level on the cassette.

Measurement

• 3rd upper premolar

• Highest point of cranium

• Most caudal aspect of muzzle (nose stop)

Beam Center

• 15° from vertical with the beam angled into the open mouth between the upper 3rd and 4th premolars

• Lateral canthus of eye

• Between the eyes

Field of View

• Tip of nose to pharyngeal area

• Tip of nose to base of skull

• Tip of nose to base of skull

Notes

• Remove or tie endotracheal tube to mandible.

• Same technique could be used to radiograph the foramen magnum. • Remove or tie endotracheal tube to mandible.

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Spine Positioning The spine must be kept level as films are taken. A misaligned spine will result in distortion on the radiograph and therefore possibly a nondiagnostic radiograph. Levelness can be accomplished with supports under the mandible, neck, or thorax or between the limbs. A “V” trough or wedges are recom-

5

mended on all ventrodorsal views to stabilize the body of the animal. Always collimate down to exclude the soft tissues. Most of these positions will require some form of sedation or general anesthesia. Abbreviations have been used to conserve space and are as follows: O = occipital, A = atlantal, C = cervical vertebra, T = thoracic vertebra, TL = thoracolumbar vertebra, L = lumbar vertebra, S = sacral vertebra

Skill Box 5.9 / Spine Positioning: Cervical Anatomic Area

Cervical

View

Lateral

V/D

Extended Lateral

Flexed Lateral

Oblique Lateral

Positioning

• Lateral recumbency • Forelimbs retracted caudally • O-A joint is flexed at a 45° angle. • Elevate the mandible to be parallel to table with support. • Gauze may be needed around the mouth to keep head pulled slightly forward.

• Dorsal recumbency • Forelimbs extended caudally alongside the body • Spine parallel to cassette • Support under the neck can minimize distortion caused by a misaligned vertebra.

• Lateral recumbency • Forelimbs extended caudally • Extend the neck dorsally until resistance is met; gauze may be placed around the muzzle • Place support under the mandible and neck to maintain a level spine (especially with longnecked dogs).

• Lateral recumbency • Forelimbs extended caudally • O-A is flexed at a 90° angle. • Elevate the neck if necessary to keep it level with the spine (wedges). • Pull the lower mandible open with gauze to maintain the 90° angle.

• Lateral recumbency • Elevate the mandible to be parallel to table with support (wedges). • Elevate the sternum 20° above vertebral level/plane with support (wedges).

Measurement

• Over C7

• C5–C6

• Thoracic inlet (C7)

• Thoracic inlet (C7)

• Thoracic inlet (C7)

Beam Center

• C4–C5 and vertebral column

• C4–C5 and vertebral column

• C4–C5 and vertebral column

• C4–C5 and vertebral column

• C4–C5 and vertebral column

Field of View

• Caudal skull to T1

• Caudal skull to T1–T2

• Caudal skull to T1–T2

• Caudal skull to T1–T2

• Caudal skull to T1–T2

Notes

• Two films are recommended for large dogs.

• Two films are recommended for large dogs.

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• Be careful not to overflex the neck, as tracheal damage may occur.

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Skill Box 5.10 / Spine Positioning: Thoracic–Lumbar Anatomic Area

Thoracic

Thoracolumbar

Lumbar

View

Lateral

V/D

Lateral

V/D

Lateral

V/D

Positioning

• Lateral recumbency • Forelimbs extended cranially • Hindlimbs extended caudally • Elevate sternum to thoracic vertebrae level to reduce rotational artifact.

• Dorsal recumbency • Forelimbs extended cranially • Hindlimbs in a relaxed position

• Lateral recumbency • Forelimbs slightly extended cranially • Hindlimbs slightly extended caudally

• Dorsal recumbency • Forelimbs extended cranially • Hindlimbs in a relaxed position

• Lateral recumbency • Forelimbs in a relaxed position • Hindlimbs extended caudally with support between them to keep hips parallel to the table

• Dorsal recumbency • Forelimbs extended cranially • Hindlimbs in a relaxed position

Measurement

• 7th–8th rib

• Highest point of the sternum

• TL junction

• TL junction

• Thickest area (L1)

• Thickest area (L1)

Beam Center

• T6–T7

• T6–T7 (caudal border of scapula)

• TL junction

• TL junction

• L4

• L4

Field of View

• C7–L1

• C7–L1

• T8–L5

• T8–L5

• T13–S1

• T13–S1

5

Notes

• May require support under sternum and midlumbar region for proper alignment and prevention of axial rotation artifact (especially in chondrodystrophic dogs with elongated backs)

• May require support under sternum and midlumbar region for prevention of axial rotation artifact

Skill Box 5.11 / Spine Positioning: Sacrum—Caudal Anatomic Area

Sacrum

Caudal

View

Lateral

V/D

Lateral

V/D

Positioning

• Lateral recumbency • Hindlimbs are slightly apart and relaxed with a support between them. • Tail is extended caudally, not supported.

• Dorsal recumbency • Hindlimbs are relaxed in semiflexion.

• Lateral recumbency • Tail is extended caudally and supported as needed to prevent excessive sagging or lateral flexion.

• Dorsal recumbency • Hindlimbs are relaxed in semiflexion. • Tail is extended straight caudally and supported as needed to prevent excessive sagging or lateral flexion.

Measurement

• Trochanters

• Mid-sacrum

• Area of concern

• Area of concern

Beam Center

• Greater femoral trochanter

• At 30° toward pubis

• Area of concern

• Area of concern

Field of View

• Pelvis to proximal caudal vertebral segments

• L6 to proximal caudal vertebra

• Includes area of concern plus several vertebra on either side

• Includes area of concern plus several vertebra on either side CHAPTER 5 / IMAGING

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Shoulder and Forelimb Positioning Skill Box 5.12 / Shoulder and Forelimb Positioning: Scapula–Shoulder Anatomic Area

Scapula

Shoulder

View

Lateral—With Tension

Lateral—Without Tension

Caudocranial

Lateral

Caudocranial

Positioning

• Lateral recumbency • Affected forelimb is flexed at the elbow 90° and pulled caudally until the humerus is parallel to the spine and radius/ulna are perpendicular to spine. • Unaffected forelimb is extended caudally.

• Lateral recumbency • Affected forelimb extended caudally • Unaffected forelimb extended cranially

• Dorsal recumbency • Forelimbs extended cranially. • Sternum is rotated slightly away from the scapula of interest (just opposite midline).

• Lateral recumbency • Affected forelimb extended cranially • Unaffected forelimb flexed caudodorsally, parallel to the thorax • Head extended cranially

• Dorsal recumbency • Forelimbs extended cranially

Measurement

• Thickest area of shoulder/cranial thorax

• Thickest area of shoulder/cranial thorax

• Thickest area of shoulder

• Over manubrium

• Thickest area of shoulder

Beam Center

• Mid-scapula

• Mid-scapula

• Mid-scapula

• Shoulder joint

• Shoulder joint

Field of View

• Cranial aspect of the shoulder joint to the caudal scapular crest

• Cranial aspect of the shoulder joint to the caudal scapular crest

• Shoulder joint to T6

• Mid-scapula to mid-humerus

• Mid-humerus to mid-scapula

• Used when patient is injured or in pain

• Best method for viewing acromial process of scapular spine

• Ensure that the manubrium and cranial sternebrae do not overlap shoulder joint.

• Be aware of any rotation in the humerus that would result in an oblique view.

5

Notes

Skill Box 5.13 / Shoulder and Forelimb Positioning: Humerus Anatomic Area

Humerus

View

Lateral

Caudocranial

Craniocaudal

Positioning

• • • •

• Dorsal recumbency • Forelimbs are extended cranially. • Affected forelimb is parallel to cassette.

• Dorsal recumbency • Affected forelimb is extended caudally alongside the body but just clear of the thorax.

Measurement

• Thickest area of shoulder

• Thickest area of shoulder

• Thickest area of shoulder

Beam Center

• Mid-humerus

• Mid-humerus

• Mid-humerus

Field of View

• Shoulder joint to elbow joint

• Shoulder joint to elbow joint

• Shoulder joint to elbow joint

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Lateral recumbency Affected forelimb is extended cranioventrally. Unaffected forelimb is extended caudodorsally. Head is extended dorsally.

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Skill Box 5.14 / Shoulder and Forelimb Positioning: Elbow Anatomic Area

Elbow

View

Lateral

Flexed Lateral

Craniocaudal

Positioning

• Lateral recumbency • Affected limb extended slightly cranioventrally with elbow slightly flexed • Unaffected limb extended caudodorsally • Head is extended dorsally

• Lateral recumbency • Affected limb flexed at the elbow joint with carpus pulled toward neck. • Unaffected limb extended caudoventrally • Head is extended dorsally

• Sternal recumbency • Affected limb extended cranially • Unaffected limb acts as a support for the animal’s head. • Head is placed resting over unaffected limb.

Measurement

• Thickest part of elbow joint

• Thickest part of elbow joint during flexion

• Thickest part of elbow joint

Beam Center

• Elbow joint

• Elbow joint

• Elbow joint

Field of View

• Mid-humerus to mid-radius/ulna

• Mid-humerus to mid-radius/ulna

• Mid-humerus to mid-radius/ulna

Notes

5

• Make sure that, when pulling the carpus, the elbow does not rotate. • This view is best for screening for elbow dysplasia (especially lesions of anconeal process of ulna). • A hyperflexed view also may be needed for diagnostic analysis.

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Skill Box 5.15 / Shoulder and Forelimb Positioning: Radius/Ulna and Carpus Anatomic Area

5

Radius/Ulna

Carpus

View

Lateral

Craniocaudal

Lateral

Dorsopalmar

Positioning

• Lateral recumbency • Affected limb extended cranially and slightly flexed at the elbow • Unaffected limb extended caudally • Head is extended dorsally away from cassette.

• Sternal recumbency • Affected limb extended cranially • Unaffected limb extended cranially • Head is placed resting over unaffected limb.

• Lateral recumbency • Affected limb extended cranially • Unaffected limb extended ventrally and relaxed • Head is extended dorsally away from cassette.

• Sternal recumbency • Affected limb extended cranially • Unaffected limb extended cranially • Head is placed resting over unaffected limb.

Measurement

• Elbow joint

• Thickest area of elbow joint

• Distal carpus

• Mid-carpus

Beam Center

• Mid-radius/ulna

• Mid-radius/ulna

• Mid-carpus

• Mid-carpus

Field of View

• Distal humerus to mid-metacarpals

• Distal humerus to mid-metacarpals

• Distal radius/ulna to distal metacarpals

• Distal radius/ulna to distal metacarpals

Notes

• Avoid rotation of radius/ulna in cats.

• Support under the elbow may assist in maintaining proper carpal positioning. • Stressed views under sedation or general anesthesia may be needed to show presence of ligament laxity.

• Support under the elbow may assist in maintaining proper carpal positioning. • Oblique view at a 45° angle also may be required.

Skill Box 5.16 / Shoulder and Forelimb Positioning: Metacarpus/Phalanges Anatomic Area

Metacarpus/Phalanges

View

Lateral

Dorsopalmar

Positioning

• • • • •

• • • •

Measurement

• Middle phalanx

• Mid-metacarpal

Beam Center

• Middle phalanges or affected phalanx

• Mid-metacarpal

Field of View

• Distal radius/ulna to distal digits

• Distal radius/ulna to distal digits

Notes

• Support under the elbow may assist in maintaining proper carpal positioning. • Oblique view(s) may be needed in some cases.

• Support under the elbow may assist in maintaining proper carpal positioning. • Oblique view at 45º angle also may be required.

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Lateral recumbency Affected limb extended cranially Affected phalange is isolated with gauze or tape and pulled dorsally. Unaffected limb extended caudally and relaxed Head is extended dorsally away from cassette.

Sternal recumbency Affected limb extended cranially Unaffected limb is extended cranially. Head is placed resting over unaffected limb.

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Pelvis and Hindlimb Positioning

Skill Box 5.17 / Pelvis and Hindlimb Positioning: Pelvis Anatomic Area

Pelvis

View

Lateral

Lateral Oblique

V/D—Frog Leg

V/D—extended

Positioning

• Lateral recumbency • Hindlimbs are extended down ventrally, slightly apart with the affected limb slightly cranial to unaffected limb, separated with a support to avoid spine rotation.

• Lateral recumbency • Affected hindlimb is extended down ventrally and slightly cranially. • Unaffected hindlimb is elevated to a 20º angle dorsally.

• Dorsal recumbency • Hindlimbs should be abducted and flexed at a 45º angle to spine, positioned identically.

• Dorsal recumbency • Pelvis flat on table • Hindlimbs start in a flexed frog leg position. The area just above the hocks are grasped and limbs are rotated medially so stifles come within 1–2 inches of each other, then extended caudally over the pubis region and ending in a full straight extension of the hindlimbs with patella centered over the femurs.

Measurement

• Greater trochanter

• Greater trochanter

• Acetabulum (groin)

• Acetabulum (groin)

Beam Center

• Greater trochanter

• Greater trochanter

• Pubis/acetabulum

• Pubis/acetabulum

Field of View

• Mid-lumbar spine to mid-femurs

• Mid-lumbar spine to mid-femurs

• Mid-lumbar spine to mid-caudal vertebrae

• Mid-lumbar spine to distal stifle

Notes

• Best view for L-S bony changes if cauda equina pain suspected • Requires high mA-s to penetrate large dog’s pelvic bones

• Used if trauma to the pelvis is suspected • Sandbags and V tray will assist in proper positioning.

• Sedation is necessary. • Standard for assessment of hips • Correct positioning will result in parallel femurs; patellae centered between femoral condyles; left and right pelvis should be displayed as a mirror image. • If hip laxity is in question, sometimes the Penn-HIP method is also recommended, which requires special certification of the veterinarian.

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Skill Box 5.18 / Pelvis and Hindlimb Positioning: Femur, Stifles, and Tibia/Fibula Anatomic Area

Femur

Stifles

Tibia/Fibula

View

Lateral

Craniocaudal

Lateral

Caudocranial

Lateral

Caudocranial

Positioning

• Lateral recumbency • Affected limb joints slightly flexed and relaxed • Unaffected limb extended dorsally or abducted out of the beam

• Dorsal recumbency • Affected limb extended caudally with slight abduction • Unaffected limb is flexed and relaxed • Tail (if long) gently laid under unaffected limb

• Lateral recumbency • Affected limb slightly flexed and relaxed, with support under the hock if necessary to keep knee from rotating • Unaffected limb extended dorsally out of the beam

• Sternal recumbency • Affected limb extended caudally • Unaffected limb is flexed, relaxed, and supported.

• Lateral recumbency • Affected limb slightly flexed and relaxed, with support under tarsus to keep tibia from rotating • Unaffected limb extended cranially

• Sternal recumbency • Affected limb extended caudally • Unaffected limb is flexed, relaxed, and supported.

Measurement

• Mid-femur

• Mid-femur

• Thickest part of stifle

• Thickest part of stifle

• Mid-tibia/fibula

• Mid-tibia/fibula

Beam Center

• Mid-femur

• Mid-femur

• Mid-stifle joint

• Mid-stifle joint

• Mid-tibia/fibula

• Mid-tibia/fibula

Field of View

• Hip joint to proximal tibia/fibula

• Hip joint to proximal tibia/fibula

• Mid-femur to mid-tibia/fibula

• Mid-femur to mid-tibia/fibula

• Stifle joint to distal tarsus joint

• Stifle joint to distal tarsus joint

Notes

• Best view for bony neoplasia of femur

5

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• Depending on size of animal, elevation of the pelvic area will alleviate weight off the stifle.

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Skill Box 5.19 / Pelvis and Hindlimb Positioning: Tarsus and Metatarsals Anatomic Area

Tarsus

Metatarsals

View

Lateral

Plantarodorsal

Dorsoplantar

Lateral

Plantarodorsal

Dorsoplantar

Positioning

• Lateral recumbency • Affected limb slightly flexed and relaxed with support under tarsus • Unaffected limb extended cranially

• Sternal recumbency • Affected limb extended caudally with support under the stifle • Unaffected limb is flexed, relaxed, and supported.

• Sternal recumbency • Affected limb extended cranially with support under the stifle

• Lateral recumbency • Affected limb slightly flexed at stifle and tarsus with support under stifle • Unaffected limb extended cranially

• Sternal recumbency • Affected limb extended caudally with support under the stifle • Unaffected limb is flexed, relaxed, and supported.

• Sternal recumbency • Affected limb extended cranially with support under the stifle and stifle rotated laterally

5

Measurement

• Thickest area of tarsus

• Thickest area of tarsus

• Thickest area of tarsus

• Distal tarsal joint

• Distal tarsal joint

• Distal tarsal joint

Beam Center

• Mid-tarsus

• Mid-tarsus

• Mid-tarsus

• Mid-metatarsals

• Mid-metatarsals

• Mid-metatarsals

Field of View

• Mid-tibia/fibula to mid-metatarsals

• Mid-tibia/fibula to mid-metatarsals

• Mid-tibia/fibula to mid-metatarsals

• Distal tibia/fibula to distal digits

• Distal tibia/fibula to distal digits

• Distal tibia/fibula to distal digits

Radiographic Contrast Studies Contrast studies are done in cases in which the area of concern cannot be viewed diagnostically from the survey radiographs. The contrast provides the veterinarian with a more thorough observation of the affected area. Many of the procedures listed in the following tables are to be performed by a veterinarian only. However, the tables are provided so the technician can be ready for the procedure and efficiently assist the veterinarian throughout the pro-

cedure. Patient preparation is of extreme importance, and the animal should always be clean and dry for these procedures. In some cases, an enema and fasting may be required so that the gastrointestinal tract is clear of food or feces that could superimpose or distort the anatomic images. The technician should be aware of the possible side effects from the contrast medium and be prepared for appropriate emergency procedures. Preparation for these procedures as well as the dosage of the contrast medium should always be reviewed with the veterinarian before the procedure.

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Table 5.8 / Types of Contrast Media

5

Contrast Media

Positive Insoluble Iodine

Classification

• Barium sulfate (micropulverized suspension)

• Ionic (salt preparation)

• Nonionic (low osmolar)

• Gases

Trade Name

• Microtrast, Esophotrast, E-Z Past, Novopaque, Barotrast, Polibar

• Conray and Conray 43, Hypaque, Renografin 76 (IV, intraurethral, fistulas, intraperitoneal) • Gastrografin (oral only)

• Optiray 240, 320, and 350, Isovue (iopamidol), Omnipaque (iohexol), Visipaque (iodixanol) • Given IV, intraurethrally, into fistulas, intraperitoneally

• Carbon dioxide, nitrous oxide, oxygen, and room air

Indications

• Visualization of esophagus, stomach, small and large bowel, bronchography, and rhinography

• Intravascular usage

• Intravascular and myelographic studies

• Visualization of the bladder, peritoneum, pericardium, joints, and brain

Contraindications

• Perforations or ruptures suspected

• Myelography and arthrography • CHF, dehydration, and renal failure

• CHF and renal failure

• Areas not able to tolerate a transient reduction or interruption in blood flow

Side Effects

• Results in granulomas/ lesions if leaks outside GIT • Has excellent mucosalcoating properties, but can mask foreign bodies

• Acute renal failure, transient pulmonary edema, diarrhea, dehydration, and vomiting (bitter tasting to cats; use gastric tube to administer)

• Less frequently noted

• Gases may result in an embolism; possibly fatal if they access the vascular system

Monitoring

• Vomiting and apnea

• Nausea, vomiting, skin erythema, facial swelling, pulmonary edema (respiration), dehydration, hypotension, hypovolemia (pulse, CRT, MM, and temperature)

Notes

• Radiopaque—shows white on radiograph

• Radiopaque—shows white on radiograph • Patient must be well hydrated for any ionic contrast medium.

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Positive Soluble Iodine

Negative

• Radiolucent—show up black on radiograph • May be combined with other contrast media for doublecontrast images

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Fistula Contrast Studies

Abdominal Contrast Studies

Skill Box 5.20 / Fistulography

Skill Box 5.21 / Abdominal Contrast Studies: Peritoneography

Procedure

Fistulography

Procedure

Area of Study

• Fistulous tracts and draining wounds

Peritoneography (Celiography) Positive Contrast

Area of Study Indications

• Nonresponsive draining wound

• Peritoneal cavity (diaphragm, abdominal wall, and serosal surfaces of abdominal viscera)

Contraindications

• None

Indications

• Suspected presence of diaphragmatic hernia

Contrast Media

• Positive, negative or double

Contraindications

• None

Equipment

• Balloon-tip catheter

Contrast Media

• Positive (iodinated)

Patient Preparation

• Sedation • Survey radiographs

Equipment

• ± Catheter/needle

Patient Preparation Technique

1. Place catheter into the sinus or fistula. 2. Inject ionic or nonionic iodinated contrast media to fill the cavity. 3. Leave catheter in place and radiograph.

• Sedation or general anesthesia • Empty patient’s bladder. • Abdominal survey radiographs

Technique

1. Needle or catheter placement into the peritoneal cavity (lateral to midline and caudal to umbilicus) 2. Aspiration test performed (injection into the umbilical fat will invalidate the study) 3. Infusion of nonionic iodinated contrast media and animal rolled carefully 4. Radiograph

Radiographic Views

• R- and L-LAT, VD, DV

Radiographic Views

LAT, VD, ± oblique

5

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Gastrointestinal Tract Contrast Studies Skill Box 5.22 / Gastrointestinal Tract Contrast Studies: Esophagography and Gastrography Procedure

5

Esophagography

Gastrography Positive Contrast Study

Negative Contrast Study (Pneumogastrogram)

Double-Contrast Study

Area of Study

• Esophageal location and morphology

• Gastric morphology

• Gastric morphology

• Gastric morphology

Indications

• Vomiting of undigested food, gagging, or dysphagia

• Gastric masses/foreign body, or vomiting

• Gastric masses/foreign body, or vomiting

• Gastric masses/foreign body, or vomiting

Contraindications

• Inability to swallow, bronchoesophageal, rupture/ perforation, or dyspnea

• Parasitic infection

• Presence of ingesta or fluid

• Diabetes mellitus (if glucagon will be used)

Contrast Media

• Barium sulfate or if perforation is suspected iodinated contrast

• Barium sulfate 30–50% • Organic iodide (diatrizoate solution 10%)

• Carbon dioxide, nitrous oxide, or oxygen

• Barium sulfate 30%–50% and a negative contrast gas

Equipment

• Large syringe • Wet towels

• • • •

• Orogastric tube (only if gas is to be used) • Large syringe • 3-way valve • Bite block

• • • • •

Patient Preparation

• Fasting: 12 hours • Survey radiographs • Conscious patient

• Fasting: 12–24 hours • Large bowel evacuation or enema • Survey radiographs • Conscious patient

• Fasting: 12–24 hours • Survey radiographs • Conscious patient

• Fasting: 12–24 hours • Survey radiographs • Conscious patient

Technique

Technique I Mucosal assessment 1. Place patient in lateral recumbency. 2. Administer positive contrast medium into the buccal pouch. 3.Radiograph as the patient swallows. Technique II Stricture 1. Feed varying sizes of barium-filled gelatin capsules, barium-injected marshmallows, or mix with food. 2. Radiograph

1. Administer positive contrast medium (∼4– 8 mL/kg) orally with a syringe or through an orogastric tube. • Radiograph

1. Insert an orogastric tube into the stomach; verify placement. 2. Administer ∼5–8 mL/kg gas (air or carbon dioxide). 3. Remove orogastric tube and hold muzzle closed while radiographing.

1. Insert an orogastric tube into the stomach; verify placement. 2. Administer positive contrast medium (2 mL/kg). 3. Follow with 10–20 mL/kg gas (air or carbon dioxide) to achieve a tympanic stomach. 4. Roll patient to coat stomach and radiograph.

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Orogastric tube Large syringe Wet towels Bite block

Orogastric tube Large syringe Wet towels 3-way valve Bite block

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Skill Box 5.22 / Gastrointestinal Tract Contrast Studies: Esophagography and Gastrography (Continued) Procedure

Esophagography

Gastrography Positive Contrast Study

Negative Contrast Study (Pneumogastrogram)

Double-Contrast Study

Radiographic Views

• R-LAT, R-VD OBL of neck and thorax

• R- and L-LAT, DV, VD

• R- and L-LAT, DV, VD

• R- and L-LAT, DV, VD

Notes

• Monitor for aspiration of contrast. • Fluoroscopy may aid in evaluation of motility and function. • Iodinated contrast materials are bitter tasting and may result in vomiting. They are also hypertonic (if inhaled, could result in pulmonary edema). • General anesthesia is not recommended because of the risk of aspiration after vomiting.

• Monitor for aspiration of contrast. • General anesthesia is not recommended because of inhibition of GI motility and risk of aspiration after vomiting.

• Monitor for aspiration of contrast. • General anesthesia is not recommended because of inhibition of GI motility and risk of aspiration after vomiting.

• Monitor for aspiration of contrast. • Fluoroscopy may aid gastric lesion evaluation. • General anesthesia is not recommended because of inhibition of GI motility and risk of aspiration after vomiting.

5

Note: See Skill Box 12.1 Stomach Tube and Gastric Lavage, page 428.

Skill Box 5.23 / Gastrointestinal Tract Contrast Studies: Upper and Lower Gastrointestinal Study Procedure

Upper Gastrointestinal Study (UGI) Barium

Upper Gastrointestinal Study (UGI) Iodinated Contrast

Lower Gastrointestinal Study (LGI) Double-Contrast Barium Enema

Area of Study

• Small intestine morphology and functionality

• Small intestine morphology and functionality

• Large bowel morphology

Indications

• Vomiting, diarrhea, neoplasias, or obstructions

• Bloody diarrhea

• Large bowel obstruction or bloody diarrhea

Contraindications

• Perforated esophagus or stomach • Lower bowel obstruction

• Dehydrated patient • Hypertonic mediums should not be used in hypovolemic patients (e.g., Gastrografin).

• Rupture/perforation

Contrast Media

• Barium sulfate 30%

• Ionic or nonionic iodinated contrast

• Barium sulfate diluted (10–20%)

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Skill Box 5.23 / Gastrointestinal Tract Contrast Studies: Upper and Lower Gastrointestinal Study (Continued)

5

Procedure

Upper Gastrointestinal Study (UGI) Barium

Upper Gastrointestinal Study (UGI) Iodinated Contrast

Lower Gastrointestinal Study (LGI) Double-Contrast Barium Enema

Equipment

• • • •

• • • •

• • • • • • • •

Examination gloves Warmed barium sulfate Enema syringe Lubricant Foley catheter 3-way stopcock Compression paddle Wet towels

Patient Preparation

• Fasting: 24 hours • Tepid saline enema 4–12 hours before • Chemical restraint may be necessary; however, do not use parasympatholytic agents. • Conscious patient • Survey radiographs

• Fasting: 24 hours • Tepid saline enema 4–12 hours before • Chemical restraint may be necessary; however, do not use parasympatholytic agents. • Conscious patient • Survey radiographs

• • • •

Fasting: 24 hours Oral laxative and tepid water (or isotonic saline) enema General anesthesia Survey radiographs

Technique

1. Administer barium (∼4–8 mL/kg) orally with a syringe or through an orogastric tube. 2. Radiograph

1. Administer iodinated contrast (∼4–8 mL/kg) orally with a syringe or through an orogastric tube. 2. Radiograph

1. Place the animal in right lateral recumbency and insert the balloon catheter in the anus and inflate the balloon to completely occlude the anal canal. 2. Slowly infuse the diluted, body temperature barium sulfate mixture into the large bowel and cecum (∼10–15 mL/kg). 3. Clamp catheter and radiograph (add more contrast medium if bowel distention is not sufficient). 4. After these radiographs have been completed: evacuate the barium, place the animal in left lateral recumbency and infuse gas to redistend the colon. 5. Radiograph

Radiographic Views

Minute Exposure • 0 minutes: R- and L-LAT, VD • 5–15 minutes: R-LAT, VD • 30 minutes: R-LAT, VD • ± 45 minutes: R-LAT, VD • ± Q60 minutes: R-LAT, VD • Considered complete when stomach is empty and contrast medium is in the large intestines.

• LAT, VD every 10–30 minutes until the contrast medium is in the large intestine

• Right LAT, VD abdominal after barium infusion and then again after gas infusion

Notes

• Care must be taken on choice of anesthesia/sedation so as not to impede the motility of the GIT.

• Care must be taken on choice of anesthesia/sedation so as not to impede the motility of the GIT.

• If study is for diagnosis of obstruction or intussusception, no fecal evacuation is necessary. • Elevation of the cranial two thirds of the body may assist removal of the contrast media.

Orogastric tube Wet towels Large syringe Bite block

Orogastric tube Wet towels Large syringe Bite block

Note: See Skill Box 12.1 Stomach Tube and Gastric Lavage, page 428.

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Head Contrast Studies Skill Box 5.24 / Head Contrast Studies: Dacryocystorhinography, Rhinography, and Sialography Procedure

Dacryocystorhinography

Rhinography

Sialography

Area of Study

• Nasolacrimal duct

• Nasal cavity

• Salivary ducts and glands

Indications

• Conjunctivitis, dacryocystitis, or neoplasia

• Suspected obstruction

• Mucoceles, swelling, abscesses, or neoplasias

Contrast Media

• Positive iodinated

• Positive (barium sulfate 20%–30% or iodinated media)

• Positive iodinated

Equipment

• Cannula • 23–27-gauge lacrimal needle • Syringe

• Syringe

• Cannula • Syringe

Patient Preparation

• General anesthesia • Nasal survey radiographs

• General anesthesia • Nasal survey radiographs including lateral and open mouth VD views

• General anesthesia • Skull/neck survey radiographs

Technique

1. Cannulation of the superior or inferior lacrimal puncta 2. Inject iodinated contrast until several drops are seen in the external nares.

1. Infuse positive contrast into the ventral nasal meatus. 2. With the infused side dependent, elevate the nose approximately 15º.

1. Cannulation of the salivary duct 2. Injection of a small amount of iodinated contrast

Radiographic Views

• LAT, DV

• LAT, VD (open mouth)

• LAT, DV

5

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Spinal and Joint Contrast Studies Skill Box 5.25 / Spinal and Joint Contrast Studies: Myelography and Epidurography Procedure

Myelography

Epidurography

Area of Study

• Spinal cord

• Epidural space

Indications

• Clinical transverse myelopathies

• Disc protrusion/extrusion, suspected lesion, or tumor

Contraindications

• Disseminated myelopathy, meningopathy, cerebrospinal fluid (CSF) infection

Contrast Media

• Positive nonionic media only (e.g., iopamidol, iohexol)

• Positive nonionic media only (e.g., iopamidol, iohexol)

Equipment

• 20–22-gauge spinal needle in various sizes: 11/2, 21/2, and 31/2

• Spinal needle

Patient Preparation

• General anesthesia • Spinal survey radiographs • Aseptic preparation of appropriate spinal location

• General anesthesia • Spinal survey radiographs • Aseptic preparation of lumbosacral or coccygeal interarcuate space

Technique

1. Aseptic spinal puncture of subarachnoid space at either cisterna magna or an interarcuate space of caudal lumbar spine (L5–L6) 2. Inject nonionic contrast media slowly to fill the subarachnoid space. 3. The needle may be removed or left in place for the radiographs.

1. Place patient in sternal or lateral recumbency. 2. Aseptic placement of spinal needle into the floor of the spinal canal at the lumbosacral or coccygeal interarcuate space 3. Inject nonionic contrast media to fill the space. 4. The needle is removed.

Radiographic Views

• LAT, VD, DV, OBL, extended/flexed LAT

• LAT, flexed LAT, Extended LAT, VD or DV

Notes

• Tilting of the body may be necessary to assist in the coating of the contrast media. • Elevate head during recovery. • Monitor for apnea and seizures.

5

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Skill Box 5.26 / Spinal and Joint Contrast Studies: Discography and Arthrography Procedure

Discography

Arthrography

Area of Study

• Central portion of intervertebral disc

• Joint evaluation (shoulder and stifle)

Indications

• Hernia or rupture

• Articular defects or joint capsule abnormalities

Contrast Media

• Positive nonionic media only (e.g., iopamidol, iohexol)

• Positive iodinated diluted to veterinarian’s recommendation

Equipment

• • • •

Spinal needle Sterile gloves Slides Culture

• Sterile gloves • 22-gauge needle • Slides

Patient Preparation

• • • • •

Spinal needle Sterile gloves General anesthesia Spinal survey radiographs Aseptic preparation of appropriate disc space

• General anesthesia • Joint survey radiographs • Prepare area around joint of interest.

Technique

1. Place patient in lateral recumbency. 2. Aseptical placement of spinal needle through the interarcurate ligament and spinal canal into the disc of interest 3. Inject nonionic contrast media into the space. 4. Radiograph

Radiographic Views

• Neutral LAT, hyperflexed, LAT, DV or VD

Notes

5

1. Aseptic articular puncture 2. Removal of small amount of joint fluid for analysis 3. Diluted nonionic contrast media is injected, dependent on animal size as per veterinarian’s recommended dosage 4. Needle is removed. 5. Joint is manipulated and radiographed. • Caudocranial LAT OBL • Radiographs should be taken as soon as contrast is injected. • Positive contrast study provides more information. • Double-contrast study is not recommended.

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Urethra Contrast Studies Skill Box 5.27 / Urethra Contrast Studies: Urethrography, Canine Procedure

5

Urethrography Canine: Male

Canine: Female

Area of Study

• Urethra location and morphology

• Urethra location and morphology

Indications

• Stranguria, hematuria, dysuria, suspected masses or lesions

• Stranguria, hematuria, dysuria, suspected masses or lesions

Contraindications

• Uncontrolled hematuria

• Uncontrolled hematuria

Contrast Media

• Iodinated contrast medium (1 part iodine to 2 parts water; 10–15% solution)

• Iodinated contrast medium (1 part iodine to 2 parts water; 10–15% solution)

Equipment

• Urinary catheter (Foley, soft polyethylene male catheter) prefilled with contrast media • Large syringe • 3-way stopcock • Sterile saline • Lubricant • Wet towels • Bowl • Lidocaine

• Urinary catheter (Foley, Swan-Ganz, soft polyethylene male catheter) prefilled with contrast media • Large syringe • 3-way stopcock • Sterile saline • Lubricant • Wet towels • Bowl • Radiolucent paddle or wooden spoon

Patient Preparation

• • • •

• • • •

Technique

Retrograde Urethrography 1. Aseptic placement of a urinary catheter to distal urethra 2. ± Infuse 2–5 mL of lidocaine to ↓ urethral spasms. 3. Infuse undiluted contrast (10–20 mL) to fill urethra. 4. Radiograph during administration of the last few mLs of contrast medium. Repeat infusion for additional radiographs. Antegrade Urethrography 1. Aseptic placement of a urinary catheter to distal urethra 2. ± Infuse 2–5 mL of lidocaine to ↓ urethral spasms. 3. Infuse enough undiluted contrast to fill the bladder and induce urination. 4. Radiograph during voiding; gentle pressure may need to be applied to the bladder.

Retrograde Urethrography 1. Aseptic placement of a urinary catheter to distal urethra 2. ± Infuse 2–5 mL of lidocaine to ↓ urethral spasms. 3. Infuse undiluted contrast (5–10 mL) to fill urethra. 4. Radiograph during administration of the last few mLs of contrast medium. Repeat infusion for additional radiographs. Antegrade Urethrography 1. Aseptic placement of a urinary catheter to distal urethra 2. ± Infuse 2–5 mL of lidocaine to ↓ urethral spasms. 3. Infuse enough undiluted contrast to fill the bladder and induce urination. 4. Radiograph during voiding; gentle pressure may need to be applied to the bladder.

Radiographic Views

• LAT (including perineal area) • Repeat infusion for any additional radiographs.

• LAT, VD

Notes

Antegrade • Can be performed after positive contrast cystogram or urethrogram. • Be prepared to catch voided urine.

Fasting: 24 hours Enema 4 hours before Sedation Survey radiographs • Lateral of perineal and penile regions with hindlimbs extended cranially

Fasting: 24 hours Enema 4 hours before Sedation Survey radiographs

Note: See Skill Box 12.10 Urinary Catheterization, page 435.

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Skill Box 5.28 / Urethra Contrast Studies: Urethrography, Feline Procedure

Urethrography Feline: Male and Female

Area of Study

• Urethra location and morphology

Indications

• Stranguria, hematuria, dysuria, suspected masses or lesions

Contraindications

• Uncontrolled hematuria

Contrast Media

• Iodinated contrast medium (1 part iodine to 2 parts water; 10–15% solution)

Equipment

• • • • • • • •

Urinary catheter (tomcat catheter for males) prefilled with contrast media Large syringe 3-way stopcock Sterile saline Lubricant Wet towels Bowl Lidocaine

Patient Preparation

• • • •

Fasting: 24 hours Enema 4 hours before Sedation Survey radiographs

Technique

Retrograde Urethrography 5. Aseptic placement of a urinary catheter to distal urethra 6. ± Infuse 2–5 mL of lidocaine to ↓ urethral spasms. 7. Infuse undiluted contrast (5–10 mL) to fill urethra. 8. Radiograph during administration of the last few mLs of contrast medium. Repeat infusion for additional radiographs. Antegrade Urethrography 5. Aseptic placement of a urinary catheter to distal urethra 6. ± Infuse 2–5 mL of lidocaine to ↓ urethral spasms. 7. Infuse enough undiluted contrast to fill the bladder and induce urination. 8. Radiograph during voiding; gentle pressure may need to be applied to the bladder.

Radiographic Views

• LAT, ± OBL

5

Note: See Skill Box 12.10 Urinary Catheterization, page 435.

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Vaginal Contrast Studies Skill Box 5.29 / Vaginal Contrast Studies: Vaginography Procedure

Vaginography Retrograde Vaginourethrography

5

Area of Study

• Vagina, cervix, and urethra morphology

Indications

• Masses, suspected ectopic ureter

Contraindications Contrast Media

• Iodinated contrast medium (1 part iodine to 2 parts water; 10–15% solution)

Equipment

• • • • • • • •

Urinary catheter (Foley, soft polyethylene male catheter) prefilled with contrast media 2 syringes (20–60 mL) 3-way stopcock Sterile saline Lubricant Wet towels Bowl Suture or Babcock forceps

Patient Preparation

• • • •

Fasting: 24 hours Enema 4 hours before General anesthesia Survey radiographs

Technique

• • • •

Place a urinary catheter into the vulva and cuff inflated just inside the vaginal vault. ± Pursestring suture or a Babcock forceps is used to keep the vulvar lips closed and the Foley catheter in place during the procedure. Infuse with undiluted iodinated contrast media to fill the vagina (e.g., back pressure felt on syringe). Radiograph as the infusion is administered, while the vagina is distended.

Radiographic Views

• LAT of pelvis and caudal abdomen, ± VD

Notes

• Overdistention of the vagina forces the contrast medium up the urethra and into the bladder.

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Urinary Tract Contrast Studies Preparation of the patient is extremely important in producing good-quality contrast radiographs of the urinary tract. An enema should always be done before the procedure, because fecal compression on the ureters or the dorsal bladder wall can ruin a study. The enema should be a warmed isotonic saline

enema. Hydration should be assessed and stabilized before beginning any of these procedures. The technician should note the special precautions and monitoring needed when doing an IVU/EU/IVP. Although rare, when complications do occur, they can be fatal, and being prepared for the possible emergency situation can make a difference.

Skill Box 5.30 / Urinary Tract Contrast Studies: Cystography Procedure

Cystography

Procedure

Intravenous Urography (IVU), Excretory Urography (EU), Intravenous Pyelography (IVP) Area of Study

• Urinary system: kidneys, ureters, and urinary bladder

Indications

• Pyuria, hematuria, masses, tender abdomen, abnormal renal size, incontinence, trauma, or suspected ectopic ureters

Contraindications

• • • •

Contrast Media

• Iodinated contrast for intravascular injection; warmed

Equipment

• • • • • • •

IV catheter; large bore, short (contrast is viscous) Syringe 22-gauge—1-inch needle Iodinated contrast Compression bandage Fluids ready to use Resuscitation kit (epinephrine, AMBU bag, oxygen ready)

Patient Preparation

• • • • • • •

24-hour fast but have water available Enema (warm, isotonic saline): 4 hours prior Hydration assessed, stabilized, and monitored Urine sample obtained prior to procedure IV catheter Sedation or general anesthesia Abdominal survey radiographs

Cystography

5

Intravenous Urography (IVU), Excretory Urography (EU), Intravenous Pyelography (IVP) Technique

1. Rapid (1–3 minutes) intravenous infusion of a warmed iodinated contrast media (3 mL/kg; 90 mL maximum) 2. Radiograph immediately and follow-up radiographs as listed below

Radiographic Views

Minute Exposure • 0 minutes: VD, LAT • 3–5 minutes: VD, ± LAT, ± VD OBL, ± R-LAT OBL • 10–15 minutes: VD, LAT, ± LAT OBL • 30–120 minutes: VD, LAT, ± LAT OBL

Notes

• Monitor for hypotension, vomiting, arrhythmia, cardiovascular collapse, anaphylaxis, and contrast medium–induced acute renal failure (CMIARF). • Abdominal compression may be used to visualize the renal collecting system and proximal ureters. • Oblique radiographs may be required to visualize the distal ureters. • Do not use soapy enemas. • Contrast media may cause vasodilation and stinging. • Three stages include nephrogram, pyelogram, and cystogram.

Hypovolemia Creatinine >3–3.5 mg/dL Dehydration No compression if abdominal masses or enlarged or cystic kidneys are suspected

Note: See Skill Box 8.9 Intravenous Catheter Placement, Peripheral and Jugular, page 349.

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Skill Box 5.31 / Urinary Tract Contrast Studies: Cystography (continued) Procedure

5

Cystography Positive Contrast

Negative Contrast (Pneumocystography)

Double Contrast

Area of Study

• Urinary bladder wall integrity and position

• Urinary bladder

• Urinary bladder mucosal detail

Indications

• Trauma, hematuria, or straining

• Trauma, hematuria, or straining

• Trauma, hematuria, or straining

Contraindications

• Enlarged bladder

• Enlarged bladder

• Enlarged bladder

Contrast Media

• Iodinated contrast (1 part contrast to 3 parts water)

• Gas (carbon dioxide, nitrous oxide, oxygen)

• Negative and positive iodinated contrast media

Equipment

• Urinary catheter (Foley, tomcat, or soft flexible male catheter) • Large syringe • 3-way stopcock • Sterile saline • Lubricant • Wet towels • Bowl • 5–10 mL 2% lidocaine (to ↓ spasms)

• Urinary catheter (Foley, tomcat, or soft flexible male catheter) • Large syringe • 3-way stopcock • Sterile saline • Lubricant • Wet towels • Bowl • 5–10 mL 2% lidocaine (to ↓ spasms)

• Urinary catheter (Foley, tomcat, or soft flexible male catheter) • Large syringe • 3-way stopcock • Sterile saline • Lubricant • Wet towels • Bowl • 5–10 mL 2% lidocaine (to ↓ spasms)

Patient Preparation

• 24-hour fast • Enema (warm, isotonic saline—4 hours before • Urine sample obtained before procedure • Sedation or general anesthesia • Survey radiographs

• 24-hour fast • Enema (warm, isotonic saline—4 hours before • Urine sample obtained before procedure • Sedation or general anesthesia • Survey radiographs

• • • • •

Technique

1. Aseptic placement of a urinary catheter to the bladder neck 2. Empty the bladder and note amount remove to estimate amount of contrast medium to use. 3. Infuse 5–10 mL lidocaine to ↓ bladder spasticity. 4. Infuse positive contrast medium diluted with saline (∼10 mL/kg) into the urinary catheter and monitor the bladder by palpation until distended. 5. Radiograph

1. Aseptic placement of a urinary catheter to the bladder neck 2. Empty the bladder and note amount remove to estimate amount of contrast medium to use. 3. Infuse 5–10 mL lidocaine to ↓ bladder spasticity. 4. Infuse gas (∼10 mL air/kg) into the urinary catheter and monitor the bladder by palpation until distended. 5. Radiograph

1. Aseptic placement of a urinary catheter to the bladder neck 2. Empty the bladder and note amount remove to estimate amount of contrast medium to use. 3. Infuse 5–10 mL lidocaine to ↓ bladder spasticity. 4. Infuse gas (∼10 mL air/kg) into the urinary catheter and monitor the bladder by palpation until distended. 5. Infuse a small amount (canine: 1–3 mL, feline: 1–2 mL) of iodinated contrast into the urinary catheter. 6. Roll animal to coat bladder wall and radiograph.

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24-hour fast Enema (warm, isotonic saline—4 hours before Urine sample obtained before procedure Sedation or general anesthesia Survey radiographs

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Skill Box 5.31 / Urinary Tract Contrast Studies: Cystography (continued) (Continued) Procedure

Cystography Positive Contrast

Negative Contrast (Pneumocystography)

Double Contrast

Radiographic Views

• LAT, VD OBL • If further radiographs are necessary, inject additional contrast media.

• LAT, VD, ± OBL • If further radiographs are necessary, inject additional contrast media.

• LAT, VD OBL

Notes

• Complications may include trauma due to improper catheterization, iatrogenic infection, or chemical cystitis.

• Room air may cause an air embolus; carbon dioxide is recommended. • Complications may include trauma caused by improper catheterization, iatrogenic infection, or air emboli.

• Room air may cause an air embolus; carbon dioxide is recommended. • Complications may include trauma caused by improper catheterization, iatrogenic infection, air emboli, or chemical cystitis.

5

Note: See Skill Box 12.10 Urinary Catheterization, page 435.

Additional Imaging Techniques In addition to radiographs, the following modalities can be used to further assist in the diagnosis of a patient’s medical problem. Survey radiographs should always be evaluated before any of these modalities. Table 5.9 / Computed Tomography and Echocardiography Procedure

Computed Tomography (CT, CAT scan)

Echocardiography

Definition

A cross-sectional image is taken by a rotating image recorder. A set of 3 images is then used by a computer to construct the final image. This technique facilitates easier visualization by avoiding superimposition of surrounding organs. CT is also able to distinguish between gas, fat, fluid, and calcification.

Noninvasive study of the heart and its structures (aorta, ventricles, atria, auricular appendages, and all the cardiac valves), using ultrasonography

Technique

• A thin rotating x-ray beam passes through the patient transaxially, and 3 views of the area of interest are reconstructed by a computer using the transmitted data onto a video screen.

• The ultrasound transducer is placed on a clipped and cleaned area with ultrasound gel. M-mode is used to view the cardiac structures and produce the image. The animal may be in lateral or dorsal recumbency or standing if necessary.

Indications

• Confirmation or further evaluation of radiographic results • Intracranial disease, musculoskeletal, spinal, thoracic, and abdominal disorders

• Visualize internal cardiac structures. • Evaluate cardiac function and size, defects (e.g., valvular lesions, shunts, myocardial abnormalities, masses, effusions, stenotic lesions). • Evaluate respiratory distress or pleural effusion.

Specialized Equipment

• CT unit

• Ultrasound machine, transducers, Doppler (permits detection and analysis of blood cells in transit), ultrasound gel

Precautions

• ↑ Risk of radiation exposure (much larger amounts used in imaging)

• None

Notes

• Two studies are usually required (with and without contrast media).

• May be necessary to clip the fur from right 3rd–6th intercostal and left 4th–7th intercostal CHAPTER 5 / IMAGING

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Table 5.10 / Fluoroscopy Procedure

Fluoroscopy

Definition

Real-time radiographic viewing of moving anatomic parts, using an x-ray machine and a fluoroscopic screen with an image intensifier

Technique

• X-rays pass through the patient’s body to the image intensifier tube.

Indications

• Used in assessing the motility and function of the pharynx, esophagus, stomach, and bowel • Evaluation of respiratory and cardiac function

Specialized Equipment

• • • • •

Precautions

• ↑ risk of radiation exposure due to high doses of radiation for this procedure

Notes

• Bone appears black and gas appears white on image. • Endoscope and ultrasound being used in place of this technique more frequently

5

Fluoroscopic x-ray tube Image intensifier tube Mirror imaging or television viewing system Radiopaque contrast medium Protective apparel

Table 5.11 / Magnetic Resonance Imaging and Nuclear Medicine Procedure

Magnetic Resonance Imaging (MRI)

Nuclear Medicine (Scintigraphy)

Definition

A cross-sectional view of a patient’s body, using magnetic fields and radio waves

The use of radiopharmaceutical drugs to ascertain the functional status of an organ or body part of a patient

Technique

• A magnet surrounds a patient’s body, and the magnetic field reacts with the hydrogen atoms in the patient’s body, which is then used to reconstruct an image by a computer onto a video screen.

• A radionuclide is administered intravenously to the patient. Travel throughout the area is captured on x-ray film, using a gamma scintillation camera.

Indications

• Confirmation of further evaluation of radiographic results • Soft tissue contrast, brain, and spine

• Specific areas requiring more information on functionality of specific organs for diagnostic assessment (e.g., hyperthyroidism, lameness, and liver dysfunction)

Specialized Equipment

• Magnetic resonance imaging unit • Special room/building for unit • Nonferrous contrast media

• • • • •

Precautions

• Patient and operator must be free of any metallic devices (pacemakers), metallic foreign bodies (bullets, shrapnel, skin staples, etc.), or ferromagnetic implants. • Operator is in a separate area from the patient.

• Requires special handling of animal’s excretion and restricted contact time with patient

Notes

• CT is preferred for bone evaluation.

• Specific drugs are used to analyze various areas.

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Radiopharmaceutical drugs Gamma scintillation camera Radiographic film Protective lab coat Specialized training in handling drug and patient’s excretions

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Ultrasonography The indications for the use of ultrasound are extensive and provide an additional level to diagnostics. This noninvasive, nonpainful technique is used as a complement to radiography to allow evaluation, diagnosis, and staging of many diseases. Ultrasound is the best modality for the evaluation of fluid-

filled and soft tissue organs, most importantly the heart. Doppler ultrasonography is an additional technique used to identify blood flow and velocity and calculate pressure of the heart and uterus. Ultrasound also excels at diagnosing discrete changes not apparent on any other test. Due to the minute complexities of ultrasound findings, it is often necessary to seek the opinion of a board-certified veterinary radiologist, when feasible and/or practical.

Table 5.12 / Ultrasonography

a

Procedure

Ultrasonography

Definition

The production of a computer image based on the emission and return of sound waves from the ultrasound’s transducer into an animal’s body

Technique

• Ultrasound transducing gel is placed on the clipped and cleaned area of interest. A transducer probe is placed on the gel. B-mode is used to view the abdominal structures. Sound waves are emitted through the transducer into the body, the sound waves strike the internal structures, and then send echoes back to the transducer. The received echoes are then reproduced as a gray scale image on the screen.

Indications

• Confirmation or further evaluation of anomalies found on radiographs • Evaluation of specific endocrine disorders (e.g., adrenal and thyroid glands) or injury/disease of: joints, tendons, cardiac, thoracic, renal, hepatic, GIT, abdominal, urogenital, ocular, vascular, pregnancy, soft tissue • Assessment of cardiac function with a Doppler ultrasonography

Specialized Equipment

• Ultrasound machine • Appropriate transducers (e.g., 5-, 7.5-MHz transducers) • Ultrasound gel

Precautions

• Biopsy complications (e.g., hemorrhage, organ laceration) due to lack of direct visualization • Artifacts on examination can lead to misleading information and an incorrect diagnosis or treatment (experience of operator critical).

Notes

• • • • • •

5

Sedation or general anesthesia may be necessary for ultrasound-guided needle aspirations and commonly used for core biopsies. Sedation if necessary for anxious or fractious patients. Sedation and general anesthesia are contraindicated when performing an echocardiogram. Owners should be made aware that a large area of fur may be clipped. Wipe probe clean of gel as soon as possible. Wash transducer probe with cold water (do not immerse) and dry with a soft towel.

Pregnancy confirmation can be done 20 (feline) or 25 (canine) days post breeding, earlier than radiographic dates.

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Skill Box 5.32 / Ultrasonography: Basic Scanning Techniquea

5

5. Choose the highest frequency transducer possible for the patient and area under examination. This provides the best resolution but also limits depth of penetration of the sound beam. 6. Set the power setting as low as possible but so that the most distal structure in the field can be seen. 7. Use the time gain compensation control to obtain an image of uniform brightness. 8. Do not press the transducer too hard against the patient as this may cause discomfort. Simply use sufficient pressure to maintain good contact between the skin and the transducer. 9. Scan slowly and thoroughly to ensure complete examination of each structure, scanning organs in at least 2 planes to allow a threedimensional impression to be built up from the cross-sectional images.

1. Prepare the patient: a. GIT scans: withhold food for 12 hours. b. Urinary tract scans: a full bladder is helpful. c. Clip and clean area of interest. d. ± sedation/anesthesia 2. Position the animal in a consistent orientation on the scanning table (this will make learning and consistent orientation of images easier). 3. If right-handed, it is usually easiest to hold the transducer in the right hand and use the left hand to make control panel adjustments. 4. Dim the room lighting to reduce reflections from the screen and enhance visualization of the image.

a

Reprinted from BSAVA Manual of Advanced Veterinary Nursing (1999), page 129; edited by Alasdair Hotston Moore with publisher’s permission.

Skill Box 5.33 / Ultrasonography: Sites for Ultrasound Scanninga Organ

Position of Animal

Area to Clip

Applications

Liver and Gall Bladder

• Dorsal or lateral recumbency or standing (may need to reposition to relocate bowel gas if it interferes)

• Ventral abdomen from xiphisternum to umbiculus, for several centimeters, to either side of midline

Liver: (deep-chested dogs)

• Left lateral recumbency

• Ventral third of last 4 ribs on right. Position transducer in intercostals spaces

• • • • •

Spleen

• Dorsal or right lateral recumbency

• As for liver, but extend farther caudally. Locate head of spleen on left, then follow body and tail.

• Focal lesions (e.g., tumors) • Diffuse lesions (e.g., venous congestion, tumors)

Kidney

• Lateral recumbency with kidney to be examined uppermost (or can use sternal recumbency or standing)

• Slightly beneath sublumbar muscles • L: behind last rib • R: over last 2 intercostal spaces

• Dorsal recumbency

• Ventral abdomen (but flank approach as above is best)

• • • • •

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Focal lesions (e.g., tumors) Diffuse lesions (e.g., cirrhosis) Biliary obstruction Portocaval shunts Venous congestion

Focal lesions (e.g., cysts) Diffuse lesions (e.g., tumors) Hydronephrosis Pyelonephritis Renal calculi

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Skill Box 5.33 / Ultrasonography: Sites for Ultrasound Scanninga (Continued) Organ

Position of Animal

Area to Clip

Applications

Ovary

• Lateral recumbency as for kidney

• As for kidney • Adrenal located cranial pole of kidney

• Polycystic ovaries • Tumors

Adrenal

• Lateral recumbency as for kidney

• As for kidney • Adrenal located cranial pole of kidney

• Hyperplasia (e.g., Cushing’s) • Neoplasia

Bladder

• Dorsal or lateral recumbency or standing

• Ventral midline from umbilicus to pubic brim, or to 1 side of prepuce in male dogs

• Cystic calculi • Tumors • Cystitis

Prostate

• Dorsal or lateral recumbency

• To 1 side of prepuce just in front of pubic brim. Locate bladder, then move caudally.

• Focal lesions (e.g., cysts) • Diffuse lesions (e.g., tumors) • Paraprostatic cysts

Uterus

• Dorsal or lateral recumbency

• Ventral midline from umbilicus to pubis

• • • •

Testicle and Scrotum

• Dorsal or lateral recumbency

• Scrotal testicles rarely require any clipping

• Scrotal hernia • Tumors • Abscesses

Cryptorchid Testicle

• Dorsal or lateral recumbency

• Pubis to umbilicus on appropriate side of midline. Start in front of pubis and work toward bladder and then kidney.

• Location of intra-abdominal testicle

Pancreas

• Dorsal recumbency

• Entire ventral abdomen from xiphistermun to umbilicus

• Pancreatitis • Tumors

Gastrointestinal Tract

• Dorsal recumbency

• Entire ventral abdomen

• Bowel wall thickening • Intussusception • Intestinal tumors

Abdomen

• Dorsal recumbency

• Entire ventral abdomen

• Free fluid • Unidentified masses (e.g., mesenteric tumors)

Heart

• Left and right lateral recumbency • Best to use a table with a hole cut so can scan from beneath; this keeps heart close to chest wall and keeps lung out of the way.

• Ventral third of ribs 4–6. • Transducer placed in intercostal spaces

• • • •

5

Pregnancy diagnosis Fetal distress/death Pyometra Stump granuloma

Pericardial effusion Valvular disease Myocardial disease Congenital defects

CHAPTER 5 / IMAGING

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Skill Box 5.33 / Ultrasonography: Sites for Ultrasound Scanninga (Continued)

5

Organ

Position of Animal

Area to Clip

Applications

Thorax

• Left and right lateral recumbency

• Over area of interest

• Free fluid • Masses (e.g., thymic lymphoma, chest wall masses) • Diaphragmatic rupture

Eye • Most useful if direct visualization obscured

• Use local anesthetic drops on cornea

• Place transducer directly on cornea (can scan through closed eyelids but image not as good).

• Retinal detachment • Intraocular masses

Orbit

• As for the eye

• As for the eye

• Retrobulbar foreign bodies, abscesses, tumors

a

Reprinted from BSAVA Manual of Advanced Veterinary Nursing (1999), pages 129–130; edited by Alasdair Hotston Moore with publisher’s permission.

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Uterine horn Ovary

Ureter Colon

Esophagus Right kidney

Lungs

Trachea

Lungs

Spleen

Left kidney

Stomach

Ureter

Anus

Urinary bladder

Liver Heart Greater omentum (covering small intestines)

Liver

Thymus

Colon

Small intestines Urinary bladder

Heart (cardiac notch)

Figure 1.6 Internal organs: left lateral view. Figure 1.7 Internal organs: right lateral view.

Esophagus

Trachea Left subclavian artery

Lung

Heart

Superior vena cava

Aortic arch Pulmonary arteries Left atrium

Pulmonary veins

Diaphragm

Liver

Left auricle

Right atrium

Liver

Gall bladder Common bile duct

Lesser omentum Stomach Greater omentum (cut)

Liver Duodenum Pancreas Transverse colon Ascending colon Cecum

Spleen Jejunum Ileum

Pulmonary veins Left ventricle

Inferior vena cava

Coronary artery Right ventricle Apex

Rectum

Descending colon

Mesentery

Figure 1.9 Circulatory: dorsal view of heart.

Anal gland

Figure 1.8 Internal organs: ventral view.

CP-1

Left subclavian artery Aorta Superior vena cava Right auricle

Right atrium

Tricuspid valve Right ventricle

Figure 1.12 Circulatory: lateral view.

Apex

Semilunar valves of aorta

Left atrium

Vagosympathetic trunk Brachial plexus

Lumbo-sacral plexus

Vagus Sciatic

Bicuspid valve Left ventricle

Chordae tendineae

Femoral Radial

Median Ulnar

Ventral papillary muscle

Figure 1.10 Circulatory: internal view of heart. Figure 1.14 Nervous system: lateral view.

CP-2

Tibial

Figure 4.1 Top: Canine bone marrow aspirate showing erythroid precursors (e.g., round nuclei, coarse chromatin, blue to red cytoplasm). Bottom: The stages of erythrocyte maturation: 1, rubriblast; 2, prorubricyte; 3, rubricyte; 4, metarubricyte; 5, polychromathilic erythrocyte; 6, mature erythrocyte. (From Veterinary Hematology and Clinical Chemistry, page 151, Figure 13.4.)

Figure 4.3 Maturation stages of megakaryocytes. Large arrow, megakaryoblasts; arrowhead, promegakaryocyte; small arrow, mature megakaryocyte. (From Veterinary Hematology and Clinical Chemistry, page 153, Figure 13.8.)

Figure 4.2 Top: Canine bone marrow aspirate showing granulocytic precursors (e.g., irregularly shaped nuclei, fine chromatin pattern, purple cytoplasm). Bottom: The stages of granulocyte maturation: 1, myeloblast; 2, promyelocyte; 3, myelocyte; 4, metamyelocyte; 5, band neutrophil; 6, segmented neutrophil. (From Veterinary Hematology and Clinical Chemistry, page 151, Figure 13.5.)

CP-3

Figure 4.5 Histiocytoma: poikilocytosis, variable amount of blue cytoplasm, ↑ nuclear/cytoplasm ratio, round, oval, or irregularly shaped nuclei with lacy or finely stippled chromatin pattern. (Photograph courtesy of J. Michael Harter, DVM, originally published on Veterinary Information Network.)

Figure 4.7 Mast cell tumor: anisocytosis, round to oval nuclei, stain palely, fine to coarse, reddish-purple granules within the cytoplasm. (Photograph courtesy of J. Michael Harter, DVM, originally published on Veterinary Information Network.)

Figure 4.6 Lymphoma: dense nuclear margins, basophilic cytoplasm, granular chromatin, ↑ nuclear/cytoplasm ratio, and ≥ nucleolus. (Photograph courtesy of J. Michael Harter, DVM, originally published on Veterinary Information Network.)

Figure 4.8 Clostridium: large rods, “safety pin” appearance (non-staining spore within the sporangium). (Photograph courtesy of J. Michael Harter, DVM, originally published on Veterinary Information Network.)

CP-4

Figure 4.9 Giardia: pear-shaped, concave ventral surface, two outlined nuclei resembling eyes along with a nose and mouth, forward or “falling leaf” motility. (Photograph courtesy of J. Michael Harter, DVM, originally published on Veterinary Information Network.)

Figure 4.11 Spirochetes: stiff corkscrew helical rods with tight spirals, corkscrewing motility. (Photograph courtesy of J. Michael Harter, DVM, originally published on Veterinary Information Network.)

Figure 4.10 Campylobacter: tiny, curved rods, two attached together as a “seagull” or “W” shape, “swarm of bees,” rapid and darting motility. (Photograph courtesy of J. Michael Harter, DVM, originally published on Veterinary Information Network.)

Figure 4.12 Yeast: rarely internal structures; smaller than Giardia. (Photograph courtesy of J. Michael Harter, DVM, originally published on Veterinary Information Network.)

CP-5

Figure 4.13 Top: canine IMHA blood smear (e.g., regenerative anemia, polychromatophilic erythrocytes, nucleated erythrocytes [arrowheads]) and Howell-Jolly body (arrow). Bottom left: lead poisoning, basophilic stippling (small arrow). Bottom right: arrow, Howell-Jolly body. (From Veterinary Hematology and Clinical Chemistry, page 76, Figure 5.15.)

Figure 4.14 Distemper (arrows): round, oval, or irregular faint blue inclusions. (From Veterinary Hematology and Clinical Chemistry, page 79, Figure 5.23.)

CP-6

Figure 4.15 Feline blood smear showing macrocytic gray-blue polychromatophilic and normal RBCs, neutrophil, platelets, Howell-Jolly body (large arrow), and Hemobartonella felis (small arrows). (Photograph courtesy of Oklahoma State University Clinical Pathology Teaching Files. From Schalm’s Veterinary Hematology, page 1066, Figure 164.3.)

Figure 4.16 Canine blood smear showing polychromatophilic erythrocytes (arrowheads), nucleated RBCs (rubricytes and metarubriytes—thin arrows), and spherocytes (thick arrows). (Photograph courtesy of Oklahoma State University Clinical Pathology Teaching Files. From Schalm’s Veterinary Hematology, page 1058, Figure 163.2.)

Figure 4.17 Feline blood smear showing reticulocytes (aggregate and punctate), platelets, and polychromatic RBCs with Heinz bodies. The Heinz bodies are also seen floating freely in the background. (From Schalm’s Veterinary Hematology, page 115, Figure 19.4.)

Figure 4.19 Canine blood smear: leptocytes (arrows), folded cells (arrowheads). (From Veterinary Hematology and Clinical Chemistry, page 75, Figure 5.12.)

Figure 4.18 Feline blood smear showing iron-deficiency anemia. Blister cells (small arrows) and keratocytes (large arrows) are present. Insert: Canine blood smear showing iron-deficiency. Blister cell (small arrow) and hypochromic erythrocyte (arrowhead). (From Veterinary Hematology and Clinical Chemistry, page 73, Figure 5.5.)

Figure 4.20 Canine blood smear showing anemia from a patient with a ruptured hemangiosarcoma of the spleen. Left: Acanthocytes (arrows) and polychromatophilic cells. Right: Acanthocytes (arrows) and schistocytes (arrowheads). (From Veterinary Hematology and Clinical Chemistry, page 73, Figure 5.6.)

CP-7

Figure 4.21 Paired, teardrop-shaped structures of a dog infected with Babesia canis. (From Schalm’s Veterinary Hematology, page 158, Figure 27.7.)

Figure 4.22 Small, irregular rings found in the RBCs of a cat infected with Cytauxoon felis. (From Schalm’s Veterinary Hematology, page 160, Figure 27.10.)

CP-8

Figure 4.23 Example of the multiple appearances of the segmented neutrophil nucleus. Band neutrophils begin with a horseshoe-shaped nucleus, and as it ages, the nucleus continues to segment. (From Veterinary Hematology and Clinical Chemistry, page 126, Figure 10.2.)

Figure 4.24 Example of the multiple appearances of lymphocytes. Nucleus varies from oval to round. Cell shape varies with indentation (small arrow) by surrounding RBCs. Lymphocyte size is typically smaller than a neutrophil (large arrow). Amount of cytoplasm varies between cells. (From Veterinary Hematology and Clinical Chemistry, page 126, Figure 10.3.)

Figure 4.27 Example of the multiple appearances of eosinophils. Eosinophils are typically larger than neutrophils (arrowheads). C (canine): variable granular size and dissolving granules during staining to appear as cytoplasmic vacuoles. F (feline): barrel of rod-shaped granules that vary in density. (From Veterinary Hematology and Clinical Chemistry, page 128, Figure 10.7.) Figure 4.25 Example of the multiple appearances of monocytes. Nucleus may be round, bean, amoeboid, or horseshoe shape or segmented. Cytoplasm may contain vacuoles. Monocytes are typically larger and have a darker blue-gray cytoplasm compared to a neutrophil (large arrow). (From Veterinary Hematology and Clinical Chemistry, page 127, Figure 10.5.)

Figure 4.26 Canine blood smear with a vacuolated monocyte and RBCs exhibiting distinct central pallor. (Photograph courtesy of Oklahoma State University Clinical Pathology Teaching Files. From Schalm’s Veterinary Hematology, page 1058, Figure 163.1.)

Figure 4.28 Example of the multiple appearances of basophils. Basophils are larger than neutrophils (inset square). C (canine): sparsely granulated. F (feline): large, poorly staining gray granules packed in the cytoplasm. (LA, large animal.) (From Veterinary Hematology and Clinical Chemistry, page 129, Figure 10.8.)

CP-9

Figure 4.29 Canine blood smear showing the segmented nucleus of a neutrophil (arrow), eosinophil (arrowhead) with variable sized particles and vacuoles, and a basophil with dark purple granules and a segmented nucleus. (Photograph courtesy of Oklahoma State University Clinical Pathology Teaching Files. From Schalm’s Veterinary Hematology, page 1061, Figure 163.9.)

Figure 4.30 Feline blood smear showing moderate anisocytosis, Howell-Jolly body (small arrow), segmented neutrophils, lymphocyte, eosinophil, and platelets. (Photograph courtesy of Oklahoma State University Clinical Pathology Teaching Files. From Schalm’s Veterinary Hematology, page 1065, Figure 164.1.)

CP-10

Figure 4.31 Canine blood smear showing a megathrombocyte (arrow), spherocytes, polychromatophilic erythrocytes, neutrophil, and a reactive lymphocyte. (Photograph courtesy of Oklahoma State University Clinical Pathology Teaching Files. From Schalm’s Veterinary Hematology, page 1060, Figure 163.7.)

Figure 4.32 Canine blood smear showing toxic change in a segmented and band neutrophil. Toxic change showing cytoplasmic basophilia and Dühle bodies. (From Schalm’s Veterinary Hematology, page 371, Figure 55.5.)

Figure 4.33 Neutrophils showing toxic change with prominent cytoplasmic basophilia. Döhle Body (small arrow). Upper left inset: normal neutrophil. Lower right inset: toxic neutrophil with fine cytoplasmic vacuolation. (From Veterinary Hematology and Clinical Chemistry, page 137, Figure 12.3.)

Figure 4.36 Ancylostoma caninum. (From Internal Parasites of Dogs and Cats, page 7.)

Figure 4.34 Malassezia: small oval cells surrounded by a halo seen intracellularly in monocytic cells. (Courtesy of J. Michael Harter, DVM, originally published on Veterinary Information Network.) Figure 4.37 Ancylostoma tubaeforme. (From Internal Parasites of Dogs and Cats, page 7.)

CP-11

Figure 4.38 Crytosporidium. (Courtesy of Gary A. Averbeck.)

Figure 4.40 Dirofilaria immitis. (From Internal Parasites of Dogs and Cats, page 3.)

Figure 4.39 Dipylidium caninum. (From Internal Parasites of Dogs and Cats, page 5.)

CP-12

Figure 4.41 Echinococcus granulosus. (From Internal Parasites of Dogs and Cats, page 5.)

Figure 4.42 Giardia spp. (From Internal Parasites of Dogs and Cats, page 11.)

Figure 4.43 Isospora spp. (From Internal Parasites of Dogs and Cats, page 11.)

Figure 4.44 Taenia spp. (From Internal Parasites of Dogs and Cats, page 6.

Figure 4.45 Toxocara canis (top)/Toxascaris leonina (bottom). (From Internal Parasites of Dogs and Cats, page 9).

Figure 4.50 Cheyletiella. (From External Parasites of Dogs and Cats, page 14.)

Figure 4.46 Toxocara cati. (From Internal Parasites of Dogs and Cats, page 10.)

Figure 4.51 Ctenocephalides canis. (From External Parasites of Dogs and Cats, page 3.)

Figure 4.48 Trichuris vulpis. (From Internal Parasites of Dogs and Cats, page 10.)

Figure 4.52 Demodex canis. (Photograph courtesy of J. Michael Harter, DVM, originally published on Veterinary Information Network.)

Figure 4.47 Toxoplasma gondii. (From Internal Parasites of Dogs and Cats, page 12.)

Figure 4.49 Uncinaria stenocephala. (From Internal Parasites of Dogs and Cats, page 8.)

Figure 4.53 Dermacentor variabilis. (From External Parasites of Dogs and Cats, page 25.)

CP-13

Figure 4.56 Rhipicephalus sanguineus. (From External Parasites of Dogs and Cats, page 25.)

Figure 4.54 Linognathus setosus. (From External Parasites of Dogs and Cats, page 10.)

Figure 4.57 Sarcoptes scabiei canis. (From External Parasites of Dogs and Cats, page 17.)

Figure 4.55 Otodectes cynotis. (Photograph courtesy of J. Michael Harter, DVM, originally published on Veterinary Information Network.)

CP-14

Figure 4.58 Trichodectes canis. (From External Parasites of Dogs and Cats, page 10.)

Figure 4.59 Bacteria. Top left: rods, unstained; top right: amorphous crystals, unstained: bottom left: cocci, unstained; bottom right: cocci, gram stain. (Photograph courtesy of Joyce S. Knoll, VMD, PhD, DACVP.)

CP-15

Figure 4.60 Bacteria. [Photograph courtesy of Cheryl Stockman, MT (ASCP).]

Figure 4.62 WBCs. [Photograph courtesy of Cheryl Stockman, MT (ASCP).]

Figure 4.61 Bacteria. (From Graff’s Handbook of Routine Urinalysis, page 116, Figure 3-51.) Figure 4.63 WBCs. (From Graff’s Handbook of Routine Urinalysis, page 77, Figure 3-4.)

CP-16

Figure 4.64 Epithelial cells, WBCs, RBCs, and bacteria. (From Graff’s Handbook of Routine Urinalysis, page 134, Figure 4-2.)

Figure 4.66 Fatty cast. [Photograph courtesy of Cheryl Stockman, MT (ASCP).]

Figure 4.65 Epithelial cast. (From Graff’s Handbook of Routine Urinalysis, page 113, Figure 3-47.) Figure 4.67 Granular cast. [Photograph courtesy of Cheryl Stockman, MT (ASCP).]

CP-17

Figure 4.69 RBC cast and RBCs. (From Graff’s Handbook of Routine Urinalysis, page 110, Figure 3-43.)

Figure 4.68 Hyaline cast. [Photograph courtesy of Cheryl Stockman, MT (ASCP).]

Figure 4.70 WBC cast. (From Graff’s Handbook of Routine Urinalysis, page 194, Figure 4-92.)

CP-18

Figure 4.71 Waxy cast. (From Graff’s Handbook of Routine Urinalysis, page 208, Figure 4-112.)

Figure 4.72 Amorphous phosphate crystals. (From Graff’s Handbook of Routine Urinalysis, page 103, Figure 3-36.)

Figure 4.73 Amorphous urate crystals and an air bubble. (From Graff’s Handbook of Routine Urinalysis, page 128, Figure 3-67.)

Figure 4.74 Amorphous biurate crystals and mucous threads. (From Graff’s Handbook of Routine Urinalysis, page 180, Figure 4-71.)

CP-19

Figure 4.75 Bilirubin crystals. (From Graff’s Handbook of Routine Urinalysis, page 170, Figure 4-55.)

Figure 4.78 Cystine crystals and air bubbles. (From Graff’s Handbook of Routine Urinalysis, page 93, Figure 3-23.)

Figure 4.76 Calcium carbonate crystals. (From Graff’s Handbook of Routine Urinalysis, page 104, Figure 3-37.)

Figure 4.79 Leucine crystals. (From Graff’s Handbook of Routine Urinalysis, page 94, Figure 3-24.)

Figure 4.77 Calcium oxalate dihydrate crystals. (From Graff’s Handbook of Routine Urinalysis, page 152, Figure 4-29.)

Figure 4.80 Sulfonamide crystals. (From Graff’s Handbook of Routine Urinalysis, page 163, Figure 4-45.)

CP-20

Figure 4.81 Triple phosphate crystals. (From Graff’s Handbook of Routine Urinalysis, page 170, Figure 4-56.)

Figure 4.84 Renal epithelial cells. (From Graff’s Handbook of Routine Urinalysis, page 139, Figure 4-9.)

Figure 4.82 Tyrosine crystals. (From Graff’s Handbook of Routine Urinalysis, page 165, Figure 4-48.)

Figure 4.85 Squamous epithelial cells. (From Graff’s Handbook of Routine Urinalysis, page 141, Figure 4-12.)

Figure 4.83 Uric acid crystals. (From Graff’s Handbook of Routine Urinalysis, page 144, Figure 4-16.)

Figure 4.86 Transitional epithelial cells. (From Graff’s Handbook of Routine Urinalysis, page 81, Figure 3-8.)

CP-21

Figure 4.87 Epithelial cells and lipid droplets. (From Graff’s Handbook of Routine Urinalysis, page 220, Figure 4-130.)

Figure 4.89 Starch granules. (From Graff’s Handbook of Routine Urinalysis, page 123, Figure 3-59.)

Figure 4.90 Yeast. (From Graff’s Handbook of Routine Urinalysis, page 217, Figure 4-126.)

Figure 4.88 Capillaria plica. (From Internal Parasites of Dogs and Cats, page 14.)

CP-22

CP-23

Figure 9.1 Colorado State University Canine Acute Pain Scale. See Skill Box 9.1, Instructions for Using the CSU Acute Pain Scale. (Courtesy of Peter Hellyer, DVM, MS, DACVA, and Narda Robinson, DO, DVM, Colorado State University.)

CP-24 Figure 9.2 Colorado State University Feline Acute Pain Scale. See Skill Box 9.1, Instructions for Using the CSU Acute Pain Scale. (Courtesy of Peter Hellyer, DVM, MS, DACVA, and Narda Robinson, DO, DVM, Colorado State University.)

Chapter

6

General Medicine Cardiopulmonary 204 Asthma and Brachycephalic Airway Syndrome 204 Bronchitis and Cardiomyopathy, Hypertrophic 205 Cardiomyopathy, Dilated 208 Cardiomyopathy, Restrictive and Congenital Heart Disease 210 Endocardiosis and Heartworm Disease 211 Congestive Heart Failure 214 Hypertension and Myocarditis 215 Pneumonia and Pleural Effusion 217 Rhinitis/Sinusitis and Tracheal Collapse 219 Dermatology 220 Acne 220 Acral Lick Dermatitis, Atopy, and Flea Allergy Dermatitis 222 Food Hypersensitivity and Otitis Externa 224 Pyoderma 225 Endocrinology and Reproduction 227 Abortion and Diabetes Insipidus 227 Diabetes Mellitus 228

6

Dystocia and Eclampsia 230 Hyperadrenocorticism and Hyperparathyroidism 231 Hyperthyroidism and Hypoadrenocorticism 233 Hypoparathyroidism, Hypothyroidism, and Mastitis 235 Pregnancy and Pyometra 237 Gastroenterology 238 Anal Sac Disease, Cholangitis, and Cholangiohepatitis 238 Constipation and Megacolon 240 Diarrhea 241 Exocrine Pancreatic Insufficiency and Gastric Dilatation-Volvulus 243 Hepatic Disease/Failure 245 Hepatic Lipidosis and Inflammatory Bowel Disease 246 Megaesophagus 248 Pancreatitis and Peritonitis 249 Protein-Losing Enteropathy and Vomiting 251 Hematology 253 Anemia and Disseminated Intravascular Coagulation 253 Thrombocytopenia and von Willebrand’s Disease 254 201

Infectious Diseases 256 Brucellosis and Erhlichiosis 256 Rocky Mountain Spotted Fever and Salmon Poisoning Tetanus and Toxoplasmosis 259 Musculoskeletal 261 Arthritis 261 Cruciate Disease and Hip Dysplasia 263 Osteochondrosis and Osteomyelitis 264 Patellar Luxation and Panosteitis 266 Neurology 267 Encephalitis and Epilepsy 267 6 Intervertebral Disc Disease and Meningitis 269 Myasthenia Gravis and Myelopathy 271 Vestibular Disease and Wobbler Syndrome 272 Oncology 273 Neoplasia 273 Key Words and Termsa Adulticidal Alopecia Amyloidosis Ankylosis Aphakic Aqueous flare Arthrodesis Ascites Ataxia Atrial fibrillation Azotemia Bacteremia Biomicroscopy Blepharospasm Borborygmus Bronchiectasis Cachexia Cardiac tamponade Chemosis Comedones Coprophagia

202

258

Histiocytoma, Mammary Gland Neoplasia, and Mast Cell Tumor 275 Various Neoplasias 277 Ophthalmology 284 Anterior Uveitis and Cataracts 284 Conjunctivitis and Entropion 285 Cilia Disorders and Glaucoma 287 Keratitis and Keratoconjunctivitis Sicca 288 Lens Luxation and Prolapsed Gland of the Third Eyelid 290 Urology 292 Cystic Calculi, Feline Lower Urinary Tract Disease, and Pyelonephritis 292 Renal Failure 294 Urinary Tract Obstruction and Urinary Tract Infection 296

Abbreviations Crepitus Cyanosis Dermatophytosis Descemetocele Diskospondylitis Dyschezia Dysphagia Dysphonia Eczema Edema Edematous Encephalopathy Endophthalmitis Epididymitis Epiphoria Epistaxis Erythropoietin Fetid Folliculitis Furunculosis Glomerulonephropathy

SECTION THREE: DIAGNOSTIC SKILLS

μg, microgram μmol, micromole ACE, angiotensin-converting enzyme AChR, acetylcholine receptor ACT, activated clotting time ACTH, adrenocorticotropic hormone ADH, antidiuretic hormone AGID, agar-gel immunodiffusion Alk phos, alkaline phosphatase ALP, alkaline phosphatase ALT, alanine aminotransferase ANA, antinuclear antibody APC, atrial premature contraction/ complex ARF, acute renal failure AST, aspartate aminotransferase BP, blood pressure BUN, blood urea nitrogen CBC, complete blood count CK, creatine kinase CNS, central nervous system

Additional Resources, page cPLI, canine pancreatic lipase immunoreactivity CRF, chronic renal failure CRT, capillary refill time CT, computed tomography DIC, disseminated intravascular coagulation DJD, degenerative joint disease dL, deciliter DNA, deoxyribonucleic acid DOCP, desoxycorticosterone pivalate ECG, electrocardiogram EEG, electroencephalogram ELISA, enzyme-linked immunosorbent assay FBD, feline bronchopulmonary disease FDP, fibrin degradation product FeLV, feline leukemia virus FLUTD, feline lower urinary tract disease

Abdominocentesis, 429 Anatomy, 3 Bandaging, 405 Bathing, 53 Blood chemistries, 74 Blood gas analysis, 335 Blood pressure, 332 Blood transfusion, 367 Cardiac examination, 30 Central venous pressure, 334 Chemotherapy, 352 Chest tube placement, 431 Coagulation profiles, 115 Complete blood count, 104 Coupage, 432 Cytology, 88 Disinfectants, 627 Drug administration, 348 Electrocardiogram, 338 Endoscopy, 551 Enema, 430

Key Words and Termsa Goniometry Halitosis Hematochezia Hematuria Hemoptysis Hepatomegaly Hyperesthesia Hypertrophic Hypotonia Icterus Ileus Impetigo Inertia Intussusception Iridodenesis Isothenuric Jaundice Leukocytosis Leukopenia Lymphadenomegaly Lymphadenopathy Macrocytosis Mastocythemia Megathrombocytosis Melena Menace response Metastasis Microhepatica Morbidity Mortality Mucopurulent Myalgia Myxedema Neovascularization Nocturia Normochromic Normocytic Nystagmus Oocyst Osteopenia a

Abbreviations Palliative Pallor Pancytopenia Panophthalmitis Paresis Periuria Petechiae Phthisis bulbi Pica Pleomorphism Pleuritis Poikilocytosis Pollakiuria Prophylactic Pruritus Psychogenic Puerperal Pulse deficits Pyrexia Retinopathy Sclerosed Seborrheic Steatorrhea Stertor Strabismus Stranguria Stratum corneum Stridor Syncope Synechia Tenesmus Tetany Thrombocytopenia Thromboembolism Trigone Trismus Turgor Uveitis

FNA, fine needle aspirate (aspiration) fPLI, feline pancreatic lipase immunoreactivity FUS, feline urologic syndrome GGT, gamma glutamyl transpeptidase GI, gastrointestinal HAC, hyperadrenocorticism IFA, immunofluorescent assay IgG, immunoglobulin gamma E IgM, immunoglobulin gamma IM, intramsucular IMHA, immune-mediated hemolytic anemia IMT, immune-mediated thrombocytopenia ITP, idiopathic thrombocytopenic purpura IV, intravenous IVDD, intervertebral disc disease K, potassium KBr, potassium bromide KCS, keratoconjunctivitis sicca LA, left atrium LDH, lactate dehydrogenase LRS, lactated Ringer’s solution LV, left ventricular MCHC, mean corpuscular hemoglobin concentration MCV, mean corpuscular volume mg, millgram MRI, magnetic resonance imaging NPH, neutral protamine hagedon NPO, nothing by mouth NS, nonsuppurative NSAIDs, nonsteroidal antiinflammatory drugs

Additional Resources, page OCD, osteochondrosis dessicans OVH, ovariohysterectomy PABA, para-aminobenzoic acid PCR, polymerase chain reaction PCV, packed cell volume PD, polydipsia PDT, photodynamic therapy PE, physical examination pg, picogram pH, potential of hydrogen PPA, phenylpropanolamine PT, prothrombin time PTH, parathyroid hormone PTT, partial thromboplastin time PU, polyuria PZI, protamine zinc insulin RAST, radioallergosorbent test RBC, red blood cell ROM, range of motion S, suppurative SAP, alkaline phosphatase T3, triiodothyronine T4, tetraiodothyronine TLI, trypsin-like immunoreactivity TP, total protein TPLO, tibial plateau leveling osteotomy TSH, thyroid-stimulating hormone UA, urinalysis UTI, urinary tract infection v, variable VD, ventrodorsal VPC, ventricular premature contraction/complex vWF, von Willebrand disease WBC, white blood cell

Fecal analysis, 134 Fluid therapy, 359 Heat administration, 346 Immunology and serology, 120 Injections, 348 Insulin administration, 357 Laboratory, 71 Lymph node examination, 34 Magnetic resonance imaging, 196 Medical procedures, 427 Metered dose inhalers, 431 Microbiology, 122 Nebulization, 432 Nutrition, 57 Obesity management, 67 Orthopedic examination, 36 Otoscopic examination, 33 Oxygen therapy, 375 Pain management, 379 Parenteral nutrition, 413 Pharmacology, 567 Physical examination, 18 Physical therapy, 558 Pulmonary examination, 32 Pulse oximetry, 463 Radiographic contrast studies, 181 Radiology, 159 Recumbent patient care, 347 Surgery, 521 Thoracocentesis, 431 Ultrasonography, 197 Urinalysis, 147 Vital signs, 19 Wound management, 396

Key words and terms are defined in the glossary on page 631.

CHAPTER 6 / GENERAL MEDICINE

203

6

CARDIOPULMONARY Table 6.1 / Cardiopulmonary: Asthma and Brachycephalic Airway Syndrome Brachycephalic Airway Syndrome

Definition

Asthma and bronchitis are secondary to inflammation and airway disorders causing bronchoconstrictive episodes. The distress is often seen on expiration or as coughing fits. The causes may be allergic, bacterial, infection, pulmonary parasites, heartworm disease, or inhaled irritants.

Brachycephalic breeds have a congenital condition of obstructive airways where the soft palate overlaps the tip of the epiglottis. Common contributing causes are stenotic nares and elongated soft palate; secondary everted laryngeal saccules are a sequela.

Presenting Clinical Signs

• Open-mouth breathing, coughing, wheezing, gagging, sneezing (v), dyspnea, vomiting, lethargy, and inappetance

• Coughing, gagging, panting, open mouth breathing, dyspnea, tachypnea, change in voice, and exercise intolerance

Examination Findings

• Tracheal sensitivity, tachypnea, cyanosis, respiratory crackles, and tachy- or bradycardia

• Stertor, stridor, and enlarged tonsils

General

• History/clinical signs

• History/clinical signs • Airway examination

Laboratory

• • • •

• Blood gas analysis

Imaging

• Radiographs, thoracic: pulmonary hyperinflation, aerophagia, flattened diaphragm, peribronchial or interstitial infiltration, atelectasis of middle lung or lung collapse, or pronounced bronchial pattern

• Radiographs, cervical/pharyngeal: thickened and lengthened soft palate, and tracheal stenosis • Radiographs, thoracic: tracheal stenosis or aspiration pneumonia

Procedures

• ECG: heart disease screen • Bronchoscopy: tumors and airway pathology • Cytology, tracheal or bronchial wash: eosinophils, activated macrophages, nonregenerative neutrophils, bacteria, and parasites

• Pulse oximetry • Laryngoscopy/pharyngoscopy: laryngeal and pharyngeal abnormalities • Tracheoscopy: location and severity of stenotic tracheal lesions and pharyngeal abnormalities

General

• Symptomatic • Oxygen therapy

• Surgery: nasal wedge resection, laryngeal sacculectomy, or staphylectomy

Medication

• Anthelmintics: based on diagnosis or clinical signs and geographic location • Antibiotics: chloramphenical, clavamox, trimethoprim-sulfa, tetracycline, or quinolones • Bronchodilators: aminophylline, theophylline, terbutaline, or albuterol • Corticosteroids: prednisolone, dexamethasone • Corticosteroids (inhalers): fluticasone • Cyproheptadine • Leukotriene receptor blocker: zafirlukast • Sympathomimetic: epinephrine, isoproterenol, terbutaline, albuterol

• No specific medications

Nursing Care

• Handle gently to avoid added stress.

• Intensive monitoring postoperative for signs of airway collapse (e.g., vital signs)

Diagnosis

Presentation

Asthma, Bronchitis, and Bronchopulmonary Disease (FBD)

Treatment

6

Disease

204

CBC: neutrophilia, monocytosis (v) and eosinophilia (v) Fecal analysis: parasites (e.g., Paragonimus) Baermann technique: parasites (e.g., Aelurostrongylus) Heartworm tests: antigen and antibody

SECTION THREE: DIAGNOSTIC SKILLS

Table 6.1 / Cardiopulmonary: Asthma and Brachycephalic Airway Syndrome (Continued)

Follow-Up

Disease

Asthma, Bronchitis, and Bronchopulmonary Disease (FBD)

Brachycephalic Airway Syndrome

Patient Care

• Monitor clinical signs.

• Monitor for several days postoperative for signs of aspiration while eating. • Do not encourage exercise and limit exercise in ↑ environmental temperatures.

Prevention/ Avoidance

• Early detection of recurrent infections • Eliminate any contributing environmental factors (e.g., cigarette smoke, air freshners, hair sprays, dirty furnace filters, or certain cat litters).

• Maintain appropriate weight control. • Selective breeding

Complications

• Progression of disease • Bronchiectasis

• Death from hypoxia during or following an anesthetic procedure • Incisional hemorrhage leading to laryngeal occlusion • Hyperthermia

Prognosis

• Guarded • Excellent with determination of environmental allergen

• Fair • Guarded if severely affected

Notes

Client Education

6

• Caution: Endotracheal tubes should be left in place as long as possible following an anesthetic procedure to prevent tracheal occlusion. • Continue medication despite the disappearance of clinical signs. • Lifelong medication and environmental changes may be necessary.

• Dogs should not be exercised extensively or in hot weather.

Table 6.2 / Cardiopulmonary: Bronchitis and Cardiomyopathy, Hypertrophic Disease

Bronchitis (Canine)

Cardiomyopathy, Hypertrophic Feline (Diastolic Dysfunction)

Presentation

Definition

Presenting Clinical Signs

Bronchitis is usually a progressive condition leading to permanent damage. Less frequently it can be acute with reversible damage. The causes include viral, bacterial, mycoplasma, infection, pulmonary parasites, heartworm disease, allergic, inhaled irritants, or foreign bodies.

Hypertrophic cardiomyopathy is a disease that occurs independently of other cardiac diseases. It is characterized by concentric hypertrophy of the ventricular free wall and/or intraventricular septum. This leads to decreased ventricular compliance and ventricular diastolic dysfunction.

• Cachexia, coughing, dyspnea, gagging, open mouth breathing, shortness of breath, tachypnea, wheezing, and exercise intolerance

• Anorexia, collapse, constant crying, coughing, depression, dyspnea, hindlimb paralysis, hypothermia, inactivity, reluctance to move, pain, sudden death, tachypnea

Examination Findings • Arrhythmias, cyanosis, dehydration, pyrexia, murmur, pulmonary crackles, syncope, tachycardia, tracheal sensitivity

• Atrial gallop rhythm, cyanotic nailbeds and pads, femoral pulse weak, hindlimbs cold, muffled heart sounds, pleural effusion, pulmonary edema, systolic murmur, sinus tachycardia

CHAPTER 6 / GENERAL MEDICINE

205

Table 6.2 / Cardiopulmonary: Bronchitis and Cardiomyopathy, Hypertrophic (Continued) Disease

Bronchitis (Canine)

Cardiomyopathy, Hypertrophic

General

• History/clinical signs • Airway examination

• History/clinical signs • Cardiac auscultation

Laboratory

• • • • • • •

Blood gas analysis CBC: neutrophilia or moncytosis, eosinophilia, and ↑ PCV Chemistry panel: ↑ ALT and alk phos Urinalysis: ↑ specific gravity Fecal analysis: parasites Heartworm tests: microfilaria and adult antigen Cytology, transtracheal or bronchial wash: bacterial clusters, eosinophils, macrophages, neutrophils • Bacterial and fungal culture, transtracheal or bronchial wash: isolation and identification

• Chemistry panel: ↑ CK, AST, ALT, and azotemia • Thyroid panel (T4, free T4, T3): ↑ in secondary cases due to primary hyperthyroidism

Imaging

• Radiographs, thoracic: normal in acute disease or ↑ cardiac size (v), ↑ interstitial density, aerophagia, peribronchial infiltrates, lung lobe atelectatic, flattening diaphragm, dilated airways, hyperinflation, or bronchial pattern • Echocardiogram: right heart enlargement and rule out congestive heart failure

• Radiographs, thoracic: ↑ cardiac size, valentine-shaped heart, elongated heart shadow, LA enlargement, pulmonary edema, and pulmonary vein dilation • Echocardiogram: hypertrophy of the intraventricular septum, LV posterior wall, papillary muscles, left atrial enlargement, and hyperdynamic myocardium • MRI: identifying mild disease and assessing response to therapy

Procedures

• Bronchoscopy: sputum sample, tumor, inflammation, foreign bodies, and parasites • ECG: sinus arrhythmia, peaked P waves, and a wandering atrial pacemaker

• ECG: sinus tachycardia, APCs, VPCs, ↑ P wave duration, ↑ R wave amplitudes, ↑ QRS width, atrial fibrillation • Blood pressure: hypotension

General

• Supportive • Oxygen therapy

• • • •

Symptomatic Fluid therapy Oxygen therapy Thoracocentesis

Medication

• Antibiotics: clavamox, trimethoprim-sulfa, cephalothin, enrofloxacin, or quinolones • Antitussives: hydrocodone or butorphanol • Bronchodilators: aminophylline, theophylline, or terbutaline • Corticosteroids: prednisone, dexamethasone • Corticosteroids (inhalers): fluticasone • Sympathomimetic: epinephrine, isoproterenol, terbutaline, albuterol • Tranquilizers

• • • • • • • • •

β-Blockers: propanolol or atenolol ACE inhibitor: enalapril Aspirin Bronchodilator: aminophylline Ca2+ channel blocker: diltiazem Diuretics: furosemide Sedation: acepromazine Vasodilator: nitroglycerin ointment, captopril Warfarin

Nursing Care

• Nebulization • Chest wall coupage

• Heat support • Low stress environment • Restricted activity

Treatment

6

Diagnosis

Feline (Diastolic Dysfunction)

206

SECTION THREE: DIAGNOSTIC SKILLS

Table 6.2 / Cardiopulmonary: Bronchitis and Cardiomyopathy, Hypertrophic (Continued) Disease

Bronchitis (Canine)

Cardiomyopathy, Hypertrophic Feline (Diastolic Dysfunction)

• Weight loss

• • • • •

Prevention/ Avoidance

• Maintain appropriate weight control. • Use a harness instead of a collar. • Eliminate any contributing environmental factors (e.g., cigarette smoke and dirty furnace filters). • Humidifier followed by light exercise to encourage expelling of sputum • Maintain oral health. • Heartworm prevention

• Avoid stressful situations.

Complications

• • • •

• • • • • •

Prognosis

• Good • Poor with irreversible changes from chronic bronchitis

• Fair to good with some forms if diagnosed and treated early • Poor with progressive heart failure

Notes

• Caution: Equipment used (e.g., nebulizer) needs to be thoroughly cleaned to prevent bacteria contamination.

• Caution: Aggressive fluid therapy must be monitored closely for overload and worsening disease • Pain and crying may indicate thromboembolism to posterior aortic branches.

Client Education

• • • •

Follow-Up

Patient Care

Pneumonia Bacterial infection Bronchiectasis Syncope

Observe closely for return of clinical signs Monitor blood values dependent on medical treatment chosen. Repeat echocardiogram after 4–6 months of initiating treatment. Sodium-restricted diet Warfarin use, monitor prothrombin time

6

Cardiac arrhythmias DIC Left heart failure Mitral valve regurgitation Sudden death Thromboembolism

Harnesses should be used in place of collars. Weight loss may improve symptoms. Exercise assists in clearing airways, limit if results in coughing Dental care reduces secondary bacterial infections.

CHAPTER 6 / GENERAL MEDICINE

207

Table 6.3 / Cardiopulmonary: Cardiomyopathy, Dilated Disease Canine

Feline (Systolic Dysfunction)

Dilated cardiomyopathy is a disease of the ventricular muscle. Advanced cases of disease show dilation of all chambers. Causes are typically idiopathic but have been linked in some cases to nutritional deficiencies, viral, protozoan, and immune-mediated mechanisms.

Dilated cardiomyopathy is a disease of the ventricular muscle. Advanced cases of disease show dilation of all chambers. It is most commonly caused by taurine deficiency and is typically reversible. It can also be idiopathic, often the end stage of another disease. This disease leads to CHF or low cardiac output.

Presenting Clinical Signs

• Abdominal distention, anorexia, ascites, cachexia, collapse, coughing, dyspnea, exercise intolerance, syncope, tachypnea

• Anorexia, constant crying, depression, dyspnea, inactivity, pain, posterior paresis, tachypnea, weakness, vomiting

Primary Survey Findings

• ↑ CRT, arrhythmias, atrial fibrillation, crackles, cyanosis, gallop, hepatomegaly, jugular pulse prominent, muffled heart and lung sounds, murmur, pleural effusion, pulmonary edema, pulse deficits, tachycardia, wheezes

• Arrhythmia, ↑ CRT, crackles, femoral pulse weak or absent, hepatomegaly, hypothermia, jugular vein distention or prominent pulse, murmur, ocular fundus abnormalities, pallor, pleural effusion, pulmonary edema, pulse deficits, ↓ skin turgor, soft heart and lung sounds, summation gallop, tachy- or bradycardia, ventricular gallop

General

• History/clinical signs • Cardiac auscultation • Pulmonary auscultation

• History/clinical signs • Cardiac auscultation • Pulmonary auscultation

Laboratory

• Chemistry panel: ↑ BUN, creatinine, ALT and ↓ sodium, chloride, potassium, protein • Plasma taurine and L-carnitine: ↓ • Blood gases: metabolic acidosis

• CBC: leukocytosis, anemia, ↓ PCV: <18% • Chemistry panel: ↑ CK, AST, ALT, BUN, creatinine, glucose and ↓ potassium • Urinalysis: ↑ myoglobin • Plasma taurine: <40 nmoles/L • Pleural effusion analysis: TP <4.9 g/dL and nucleated cell count <2500/mL is supportive of diagnosis

Imaging

• Radiographs, thoracic: ↑ cardiac size, LA, LV, caudal vena cava enlargement, pleural effusion and pulmonary edema • Echocardiogram: chamber enlargement and speed of velocity and flow, reduced myocardial contractility

• Radiographs, thoracic: ↑ cardiac size, rounding of cardiac apex, caudal vena cava and pulmonary veins enlarged, ascites, pleural effusion or pulmonary edema • Echocardiogram: anatomic abnormalities, dilation of LA and LV, ↓ LV contractility, valvular regurgitation, low aortic outflow velocity or LV muscle thinning • Angiocardiography: arterial thrombosis

Procedures

• ECG: atrial fibrillation, arrhythmias, low voltages (v), ↑ QRS duration, tachycardia, VPCs, and LV enlargement

• ECG: arrhythmias, ↑ amplitude and duration of P waves, left atrial or ventricular enlargement patterns, sinus bradycardia (v), atrial fibrillation, VPCs

Diagnosis

Presentation

Definition

6

208

Cardiomyopathy, Dilated

SECTION THREE: DIAGNOSTIC SKILLS

Table 6.3 / Cardiopulmonary: Cardiomyopathy, Dilated (Continued) Disease Canine

Feline (Systolic Dysfunction)

General

• Symptomatic • Thoracocentesis (palliative)

• • • •

Symptomatic Fluid therapy Oxygen therapy Thoracocentesis

Medication

• • • • • • • • • • •

• • • • • • • • •

ACE inhibitor: enalapril, captopril Arterial dilators: hydralazine Aspirin Bronchodilator: aminophylline Diuretics: furosemide Positive inotropes: digoxin, dobutamine, milrinone Sedation: acepromazine Taurine supplementation Vasodilator: nitroglycerin ointment

Treatment Follow-Up

Cardiomyopathy, Dilated

β-Blockers: sotalol ACE inhibitors: enalapril Aldsterone blocker: spironolactone Antiarrythymics: lidocaine, procainamide, mexiletine Bronchodilators: aminophylline Ca2+ channel blockers: diltiazem Diuretics: furosemide Inodilator: pimobendan Positive inotropes: digoxin and dobutamine Taurine or L-carnitine supplementation Vasodilator: nitroglycerin ointment

6

Nursing Care

• Treated as outpatient

• Heat support • Low stress environment • Nutritional support

Patient Care

• Monitor PE, radiographs, ECG, BP, and renal profile at regular intervals • Sodium-restricted diet • Restrict activity and limit exercise

• • • • •

Prevention/ Avoidance

• N/A

• Feed a high-quality diet with adequate taurine supplementation.

Complications

• Sudden death • Hypothyroidism

• Hyperthyroidism • Thromboembolism

Prognosis

• Grave: 6–24 months following diagnosis

• Good with taurine supplementation after survival of first 2 weeks. • Poor for idiopathic causes

• Great Dane, Irish Wolfhound, Saint Bernard, Doberman Pinscher, Springer Spaniel, and Cocker Spaniel

• Caution: Aggressive fluid therapy must be monitored closely for overload and worsening disease. • Pain and crying may indicate thromboembolism to posterior aortic branches. • Burmese, Abyssinian, and Siamese

Notes

Monitor taurine, electrolyte, and renal levels. Monitor blood values dependent on medical treatment chosen. Check thoracic radiographs after 1 week of initiating treatment. Repeat echocardiogram after 3–6 months of initiating treatment. Sodium-restricted diet

CHAPTER 6 / GENERAL MEDICINE

209

Table 6.4 / Cardiopulmonary: Cardiomyopathy, Restrictive and Congenital Heart Disease Cardiomyopathy, Restrictive Feline (Diastolic Dysfunction)

Congenital Heart Disease

Definition

Restrictive cardiomyopathy is a group of myocardial diseases that result in impaired ventricular filling. This impairment is unknown but might be caused by delayed myocardial relaxation or endocardial fibrosis.

Congenital heart disease is the most common heart condition in animals <1 year of age. It is a malformation of the heart or great vessels. The following is a list of congenital heart defects: patent ductus arteriosus, pulmonic stenosis, subaortic stenosis, ventricular septal defect, atrial septal defect, mitral dysplasia, tricuspid dysplasia, and tetralogy of Fallot.

Presenting Clinical Signs

• Cachexia, depression, dyspnea, hypothermia, open mouth breathing, panting, tachypnea, crackles, pain, pleural effusion, posterior paresis or paralysis, pulmonary edema

• Anoxia, dyspnea, exercise intolerance, stunted growth, seizures, syncope, tachypnea, weakness

Examination Findings

• Arrhythmia, ascites, crackles, cyanosis, gallop, jugular pulse distention, murmur, pleural effusion, pulmonary edema

• Abdominal distention, cyanosis, murmur

General

• History/clinical signs • Cardiac auscultation • Pulmonary auscultation

• History/clinical signs • Cardiac auscultation

Laboratory

• Chemistry panel: ↑ CK, AST, ALT, creatinine, potassium, and azotemia • Plasma taurine levels

• CBC: ↑ PCV

Imaging

• Radiographs, thoracic: ↑ cardiac size, valentine-shaped heart, pleural effusion, pulmonary edema, pulmonary vein dilation, atrial and caudal vena cava enlargement • Echocardiogram: dilation of atria, LV or RV, myocardial fibrosis, myocardial hypertrophy in septum or LV, valvular regurgitation, altered or prominent papillary muscles • Angiocardiography: arterial thrombosis

• Radiographs, thoracic: abnormalities in heart size and shape, major vessels and pulmonary vascularity; specific changes may vary with each defect/type • Echocardiogram: anatomic abnormalities, shunting lesion location and severity, and abnormal blood flow

Procedures

• ECG: arrhythmias, sinus tachycardia, atrial premature complexes, atrial fibrillation, ↑ amplitude and duration of P waves, or LA and LV enlargement patterns

• ECG: ± chamber enlargement patterns

General

• • • •

Symptomatic Fluid therapy Oxygen therapy Thoracocentesis/Pericardiocentesis

• Supportive • Symptomatic • Surgery: dependent on defect

Medication

• • • • • • • • •

β-Blockers: propanolol or atenolol ACE inhibitor: enalapril, captopril Antiarrhythmic: lidocaine Aspirin Ca2+ channel blocker: diltiazem Diuretics: furosemide Positive inotropes: digoxin Vasodilator: nitroglycerin ointment Warfarin

• • • • • •

Presentation

Disease

Treatment

Diagnosis

6

210

SECTION THREE: DIAGNOSTIC SKILLS

β-Blockers: atenolol Antiarrhythmic: lidocaine or procainamide Ca2+ channel blocker: diltiazem Diuretics: furosemide Positive inotropes: digoxin Vasodilators: enalapril

Table 6.4 / Cardiopulmonary: Cardiomyopathy, Restrictive and Congenital Heart Disease (Continued)

Follow-Up

Treatment

Disease

Cardiomyopathy, Restrictive Feline (Diastolic Dysfunction)

Congenital Heart Disease

Nursing Care

• • • • • •

• Treated as outpatient until complications with chronic heart failure • Standard postoperative

Patient Care

• Reevaluate patients every 2–4 months. • Sodium-restricted diet

• • • • •

Prevention/ Avoidance

• Avoid stressful situations

• Selective breeding

Complications

• Thromboembolism

• Chronic heart failure • Arrhythmias • Death

Prognosis

• Poor

• Guarded without surgery

Notes

Heat support Low stress environment Restricted activity Reradiograph within 12–24 hours to monitor pleural effusion Monitor electrolytes daily for 3–5 days. Monitor hydration and renal profile.

Monitor for clinical signs. Monitor PCV every 1–3 months. Monitor radiographs and echocardiograms at regular intervals. Restrict activity. Sodium-restricted diet

6

• Caution: Aggressive fluid therapy must be monitored closely for overload and worsening disease. • Pain and crying may indicate thromboembolism to posterior aortic branches.

Table 6.5 / Cardiopulmonary: Endocardiosis and Heartworm Disease Endocardiosis (Chronic Valvular Heart Disease, Chronic Mitral Valve Insufficiency)

Heartworm Disease

Definition

Endocardiosis is the most common cardiovascular disease in dogs. It accounts for >75% of cases of congestive heart failure in dogs. The disease is an alteration in a structure of the mitral valve complex causing malfunction and progressive secondary cardiac changes, ultimately resulting in chronic heart failure.

Heartworm disease is mostly a problem in dogs affecting most of the United States. It is an infection of Dirofilaria immitis transmitted by many species of mosquitoes. The worms reside in the pulmonary arteries and can extend into the right atrium and ventricle.

Presenting Clinical Signs

• Chronic small airway disease, congestion, cough, syncope, tachypnea, wheezing

• Cachexia, cough, dyspnea, hemoptysis, syncope, vomiting (intermittent, feline), wheezes

Examination Findings

• Arrhythmias, cardiac tamponade, chronic small airway disease, crackles, cyanosis, muffled heart sounds, pleural effusion, pulse deficits, systolic murmur, tachycardia

• Abnormal lung sounds, ascites, crackles, gallop, hypertension, murmur, organomegaly, tachycardia

Presentation

Disease

CHAPTER 6 / GENERAL MEDICINE

211

Table 6.5 / Cardiopulmonary: Endocardiosis and Heartworm Disease (Continued) Endocardiosis (Chronic Valvular Heart Disease, Chronic Mitral Valve Insufficiency)

Heartworm Disease

General

• History/clinical signs • Cardiac auscultation • Pulmonary auscultation

• History/clinical signs • Cardiac auscultation

Laboratory

• Chemistry panel: ↑ BUN, creatinine, phosphorus, ALT, AST, alk phos, ↓ albumin • Urinalysis: ↑ protein, albumin, granular cast, WBC, occult blood • Culture, blood: + supportive of diagnosis

• CBC: eosinophilia and basophilia (v) • Chemistry panel: ↑ hepatic enzymes, bile acids and ↓ albumin, globulin, azotemia • Urinalysis: ↑ protein, globulin, albumin, granular casts • ELISA: adult female worm antigens • Direct blood smear, Knott test or millipore filter test: microfilaria • Immunodiagnostic screens: microfilaria antigen • Serology: + dirofilaria

Imaging

• Radiographs, thoracic: ↑ cardiac size, pulmonary interstitial, alveolar congestion, pulmonary edema, alveolar edema, LA and LV enlargement, hilar lymphadenomegaly and anatomic changes in the LA, LV, and mainstem bronchi • Echocardiogram: anatomic changes, pleural and pericardial effusions, presence and severity of atrioventricular valve insufficiency with regurgitation, mitral valve abnormalities

• Radiographs, thoracic: enlarged, truncated or tortuous arteries, R-sided cardiac enlargement, pneumonitis, or localized or generalized interstitial and/or alveolar infiltrates • Echocardiogram: RA, RV, and pulmonary artery enlargement, worm burden and severity of disease

Procedures

• ECG: recognition and identification of arrhythmia and ↑ P wave duration

• ECG: arrhythmia, RV hypertrophy pattern or tall P waves

General

• Supportive • Symptomatic • Oxygen therapy

• Supportive • Platelet count

Medication

• • • • • • • •

• • • •

Nursing Care

• Low stress environment

Treatment

6

Diagnosis

Disease

212

ACE inhibitor: enalapril Adrenergic blocking agent: prazosin Antibiotics: penicillin,gentamicin, enrofloxacin, amoxicillin Arterial dilators: hydralazine Ca2+ channel blocker: diltiazem Diuretics: furosemide Positive inotropes: digoxin Vasodilator: nitroglycerin ointment

SECTION THREE: DIAGNOSTIC SKILLS

Adulticide: thiacetarsamide sodium or melarsamine Aspirin (low-dose) Corticosteroids: prednisone or prednisolone (cats) Larvacide: ivermectin or milbemycin

• Feed patient 1/2 hour prior to injection to observe for anorexia • Monitor for jaundice, fever, depression, dyspnea or other signs of thromboembolism • Close monitoring after administering injection for signs of toxicity (inflammation at injection site, vomiting, anorexia, lethargy, icterus, and ↑ BUN, ALT, or bilirubin

Table 6.5 / Cardiopulmonary: Endocardiosis and Heartworm Disease (Continued)

Follow-Up

Disease

Endocardiosis (Chronic Valvular Heart Disease, Chronic Mitral Valve Insufficiency)

Heartworm Disease

Patient Care

• Monitor BUN and creatinine when using diuretics and ACE inhibitors. • Monitor PE, ECG, and radiography 1 week after initiating therapy. • Monitor blood cultures and echocardiogram following antibiotic therapy. • Monitor cardiomegaly through radiographs every 6–12 months. • Restrict activity. • Sodium-restricted diet

• Monitor for jaundice, fever, depression, dyspnea or other signs of thromboembolism. • Strict confinement for 4–6 weeks • Start larvacide treatment 4 weeks post-adulticidal treatment. • Retest for microfilaria 7 weeks post-adulticidal treatment.

Prevention/ Avoidance

• N/A

• Prophylactic therapy: milbemycin oxide • Heartworm surveillance testing: 6–12 months of initiating preventative and then at regular intervals

Complications

• • • • • • • •

• • • • •

Prognosis

• Dependent of severity of disease

• Good when subclinical or mild disease • Fair with moderate to severe disease • Guarded if untreated or very high worm burden

• Poodle, Yorkshire Terrier, Cavalier King Charles Spaniel, Schnauzer, Cocker Spaniel

• Caution: Very high mortality in felines when thiacetarsamide therapy is used. • Caution: IM injection can cause pain and sterile abscesses with melarsamine. • Each injection is given in a peripheral vein at a different location as distal as possible with thiacetarsamide sodium. • Indwelling catheters are not recommended for administration.

Notes

Atrial fibrillation Death LA rupture Pulmonary and systemic emboli Right-sided heart failure Tachyarrhythmia Tamponade Toxemia

6

DIC Thrombocytopenia Heart failure Acute pulmonary thromboembolism Thiacetarsamide sodium toxicity

CHAPTER 6 / GENERAL MEDICINE

213

Table 6.6 / Cardiopulmonary: Congestive Heart Failure Disease

Congestive Heart Failure Left-Sided

Diagnosis

214

Heart failure is the failure of the left or right side of the heart to adequately pump blood through the body or through the pulmonary circulation respectively. The causes of congestive heart failure may be mechanical failure (valve insufficiency, aortic regurgitation or hypertension), myocardial failure (myocarditis, dilated cardiomyopathy or neoplasia), interference with cardiac filling (severe arrhythmia, hypertrophic cardiomyopathy or tamponade) or increased requirement for cardiac output (anemia, overexercise, pregnancy or hyperthyroidism).

Presenting Clinical Signs

• Cachexia, cough, dyspnea, hemoptysis, limb swelling, syncope, tachypnea, wheezes

• Cachexia, pallor, syncope

Examination Findings

• Arrhythmias, ascites, crackles, cyanosis, ↑ CRT, femoral pulses weak, gallop, murmur, organomegaly, pallor, pulmonary edema, pulse deficit, weak, pounding or irregular

• Arrhythmia, ascites, gallop, jugular vein distention, muffled heart sounds, murmur, organomegaly, pericardial effusion, pleural effusion, subcutaneous edema, system venous congestion

General

• History/clinical signs • Cardiac auscultation

Laboratory

• Chemistry panel: ↑ ALT, AST, alk phos, BUN, creatinine and ↓ sodium, potassium, protein • Heartworm tests: microfilaria and adult antigen

• CBC: eosinophilia (v) • Chemistry panel: ↑ ALT, AST, alk phos, GGT, BUN, creatinine, ↓ sodium, potassium, protein

Imaging

• Radiographs, thoracic: ↑ cardiac size, systemic or pulmonary venous dilation, pulmonary edema, or hilar lymphadenomegaly • Echocardiogram: cause and extent of disease, pericardial or pleural effusion, neoplasia, or heartworm disease

• Radiographs, thoracic: ↑ cardiac size, distended vena cava, pleural effusion and/or ascites, pulmonary edema, enlarged pulmonary arteries

Procedures

• ECG: arrhythmias, wide (and tall if R-sided) P waves, tall and wide QRS complexes and left axis orientation

General

• • • • •

Symptomatic Fluid therapy Oxygen therapy Thoracocentesis/pericardiocentesis/abdominocentesis, as needed Dependent on underlying condition

Medication

• • • • • • • • • • •

β-Blockers: propanolol, atenolol, or metoprolol ACE inhibitors: enalapril or captopril Arterial dilators: hydralazine Ca2+ channel blockers: diltiazem, amlodipine Diuretics: furosemide Inodilator: pimobendan Positive inotropes: digoxin, dobutamine or dopamine Sedation: morphine sulfate, acepromazine maleate Sodium nitroprusside Taurine supplementation Venodilators: nitroglycerin ointment

Nursing Care

Restrict stress: handling only for extremely necessary procedures

Treatment

6

Presentation

Definition

Right-Sided

SECTION THREE: DIAGNOSTIC SKILLS

• • • •

ACE inhibitors: enalapril or captopril Ca2+ channel blocker: amlodipine Diuretics: furosemide Positive inotropes: digoxin

Table 6.6 / Cardiopulmonary: Congestive Heart Failure (Continued) Disease

Congestive Heart Failure

Follow-Up

Left-Sided

Restrict activity and ↓ anxiety Monitor ECG, echocardiogram, serum chemistries and serum digoxin concentrations regularly Monitor resting respiratory rate (normal: <30 breaths/min) Sodium-restricted diet

Patient Care

• • • •

Prevention/ Avoidance

• Minimize stress and exercise.

Complications

• • • • • • •

Prognosis Notes

Right-Sided

Aortic thromboembolism (feline) Arrhythmias Electrolyte imbalances Digoxin toxicity Renal failure Hypertension Muscle wasting

6

• Dependent on underlying disease • Caution: Aggressive fluid therapy must be monitored closely for overload and worsening disease.

Table 6.7 / Cardiopulmonary: Hypertension and Myocarditis Hypertension

Myocarditis

Definition

Hypertension is an increase in pulmonary arterial or systemic blood pressure. It may be either a primary or secondary condition. Systemic hypertension is diagnosed through Doppler, whereas pulmonary arterial hypertension is found through cardiac catheterization.

Myocarditis is an inflammation of the heart muscle. Some causes are: infectious, viral, protozoan, ischemic injury, trauma, or toxicity. Primary infection is rare; typically, it is secondary to another disease process.

Presenting Clinical Signs

• Dependent on underlying condition • Anorexia, ataxia, blindness, circling, diarrhea, dilated pupils, disorientation, dyspnea, exercise intolerance, hemoptysis, hindleg paresis, ocular hemorrhage, PU/PD, seizures, tachypnea, vomiting

• Cough, fever, exercise intolerance, syncope, weakness

Examination Findings

• Abnormal heart and lung sounds, ascites, atrial gallop, crackles, cyanosis, edema, hypoxemia, retinal detachment, systolic murmur

• Arrhythmias, gallop, murmur, VPCs, ventricular tachycardia

Presentation

Disease

CHAPTER 6 / GENERAL MEDICINE

215

Table 6.7 / Cardiopulmonary: Hypertension and Myocarditis (Continued)

Diagnosis

Disease

Hypertension

Myocarditis

General

• History/clinical signs

• History/clinical signs (e.g., parvovirus, Chagas disease) • Cardiac auscultation

Laboratory

• CBC: neutrophilia and lymphopenia (v), thrombocytopenia, leukopenia, and ↑ PCV • Chemistry panel: ↑ phosphorus, ALT, cholesterol, BUN, creatinine, glucose, alk phos and ↓ albumin and electrolyte imbalances • Urinalysis: ↑ protein, blood, glucose and ↓ specific gravity with renal dysfunction

• Chemistry panel: ↑ CK, LDH, AST • Serology, parvovirus, toxoplasmosis, trypanosomiasis: +

Imaging

• Radiographs, thoracic: ↑ cardiac size, ↑ density, pulmonary artery dilation, ascites, neoplasia, bronchial collapse, tracheal narrowing • Radiographs, abdominal: hepatomegaly or abnormal kidneys • Echocardiogram: pulmonary hypertension, right heart dilation • Ultrasound: adrenal enlargement

• Radiographs, thoracic: pulmonary edema, congestion, pleural effusion, ↑ cardiac silhouette or rounded heart shape • Echocardiogram: pericardial effusion, thickened pericardium or mottled and patchy areas on myocardium • Angiogram: specific chamber involvement or pleural effusion

Procedures

• Blood pressure: systemic hypertension • Pulmonary catheterization: pulmonary hypertension (invasive measurement)

• ECG: arrhythmias and enlargement patterns

General

Only for Complicated Disease • Supportive • Fluid therapy • Oxygen therapy

• Supportive • Pericardiocentesis

Medication

• • • • • •

Nursing Care

• Treat as outpatient if possible to ↓ overall stress.

• Restrict activity

Patient Care

• Sodium-restricted diet • Monitor for signs of hypotension. • Monitor blood pressure every 1–2 weeks, then every 1–3 months.

• Sodium-restricted diet • Monitor ECG and auscultation. • Reradiograph

Prevention/ Avoidance

• Maintain proper weight control. • Measure BP in all renal failure patients.

• Vaccinate. • Monitor ECG and echocardiogram with patients using doxorubicin. • Avoid endemic areas (e.g., Gulf Coast).

Follow-Up

Treatment

6

216

α-Adrenergic blocker: prazosin β-Adrenergic blocker: propranolol ACE inhibitor: enalapril Ca2+ channel blocker: diltiazem or amlodipine (cats) Diuretics: furosemide Hydralazine

SECTION THREE: DIAGNOSTIC SKILLS

Dependent on underlying condition • ACE inhibitor: enalapril • Antiarrhythmics: quinidine • Diuretics: furosemide • Positive inotropes: digoxin

Table 6.7 / Cardiopulmonary: Hypertension and Myocarditis (Continued) Hypertension

Myocarditis

Complications

• • • • •

• Cardiomyopathy • Chronic heart failure

Prognosis

• Good if underlying cause can be determined and treated

Follow-Up

Disease

Notes

Renal failure Chronic heart failure Glomerulonephropathy Retinopathy/blindness CNS signs

• Dependent on extent and severity of disease

Canine Abnormal Systemic Values • Systolic: >160 mm Hg • Diastolic: >100 mm Hg Feline Abnormal Systemic Values • Systolic: >160 mm Hg • Diastolic: >120 mm Hg • An average of 3 readings should be done to adequately evaluate a patient’s blood pressure. • Avoid use of PPA. • Maintain low stress before and during the BP measurement.

6

Table 6.8 / Cardiomyopathy: Pneumonia and Pleural Effusion Pneumonia

Pleural Effusion

Definition

Pneumonia is an inflammatory response of the lungs. It is most commonly caused by bacteria but can also be caused by aspiration of ingesta, fungi, allergic, foreign body, viral, neoplasia, lung parasites, or contusions. It has a high rate of mortality and morbidity, especially in hospitalized animals.

Pleural effusion is an accumulation of fluid in the pleural cavity. It may be seen unilateral or bilateral. This is an abnormal process that has many causes, typically indicating a more severe underlying condition.

Presenting Clinical Signs

• Cachexia, dyspnea, mucopurulent nasal discharge, productive cough, tachypnea, wheezes

• Anorexia, depression, dyspnea, exercise intolerance, pallor, pleuritis, open-mouth breathing, preference for sternal recumbency, tachypnea

Examination Findings

• Crackles, cyanosis, dehydration, pyrexia, loud or asymmetric bronchial sounds, tachycardia

• Ascites, cyanosis, pyrexia, muffled heart and lung sounds, tachycardia

General

• History/clinical signs • Pulmonary auscultation

• • • •

Diagnosis

Presentation

Disease

History/clinical signs Cardiac auscultation Pulmonary auscultation Thoracic palpation and percussion

CHAPTER 6 / GENERAL MEDICINE

217

Table 6.8 / Cardiomyopathy: Pneumonia and Pleural Effusion (Continued)

Diagnosis

Disease

Follow-Up

Treatment

6

218

Pneumonia

Pleural Effusion

Laboratory

• CBC: neutrophilic leukocytosis with or without a left shift and monocytosis • Cytology, tracheal wash: ↑ neutrophils and bacteria • Culture, tracheal wash: bacteria isolation and identification

• • • •

Imaging

• Radiographs, thoracic: ↑ lung density, lung consolidation, pulmonary artery enlargement, or interstitial pattern with air bronchograms • Contrast study: swallowing disorders

• Radiographs, thoracic: ↑ cardiac size, tumor, lung lobe torsion, diaphragmatic hernia, widening of mediastinum, rounded lung lobe edges, obscured cardiac borders and diaphragm, ascites, and pleural fissure lines • Contrast study: tumor, diaphragmatic hernia, and cardiac disease

Procedures

• Bronchoscopy: foreign body or neutrophilic inflammation

• ECG: amplitudes all depressed

General

• • • •

• • • • •

Medication

• Antibiotics: dependent on type of bacteria isolated and one with good penetration into lung tissue (e.g., enrofloxacin) • Antifungal: amphotericin, flucytosine, ketaconazole, fluconazole • Bronchodilators: theophylline or terbutaline

• Antibiotics: dependent on type of bacteria isolated • Analgesics: bupivacaine, NSAIDs, morphine, meperidine

Nursing Care

• • • • • •

• Monitor temperature, respiratory rate and effort and pulse • Nutritional support • Chest tube management

Patient Care

• Airway humidification • Mild exercise • Reradiograph in 48–72 hours, then after 2–6 weeks

• Monitor radiographs

Prevention/ Avoidance

• Vaccinate

• N/A

Complications

• Chronic bronchitis • Secondary infection/sepsis

• Death

Prognosis

• Good

• Guarded to poor

Supportive Fluid therapy Oxygen therapy Surgery: lung lobectomy (rare)

Nebulization with bland aerosols Chest wall coupage Tracheal manipulation Restrict activity Alter patient’s position at least every 2 hours Nutritional support

SECTION THREE: DIAGNOSTIC SKILLS

CBC: leukocytosis and anemia Chemistry panel: ↑ globulin and ↓ albumin: <1 g/dL Serology: FeLV, FIP, FIV, or heartworm Fluid analysis: color, clarity, viscosity, specific gravity, TP, and nucleated cell count, neutrophils, macrophages, mesothelial cells, lymphocytes, eosinophils, or neoplastic cells

Symptomatic Fluid therapy Thoracocentesis Chest tube placement Surgery: thoracotomy

Table 6.8 / Cardiomyopathy: Pneumonia and Pleural Effusion (Continued) Disease

Pneumonia

Notes

Pleural Effusion • Classification of fluids: • Colorless to pale yellow: transudate • Yellow to pink: modified transudate or nonseptic exudate • Yellow to red-brown: septic exudate • Milky white: chylous • Red: hemorrhage • Pain medication may be directly injected through the chest tube to give pleural analgesia.

6

Table 6.9 / Cardiopulmonary: Rhinitis/Sinusitis and Tracheal Collapse Rhinitis/Sinusitis

Tracheal Collapse

Definition

Infection of the nasal sinuses is a common veterinary problem. There is acute rhinitis, which is self-limiting, and chronic sinusitis, which may require constant treatment. The causes are bacterial, viral, fungi, foreign body, dental disease, infectious agents, or neoplasia.

A collapsing trachea is a trachea with a range of dynamic variations resulting in collapse somewhere along its length. It may also involve the mainstem bronchi causing them to collapse also. It can be an acquired weakness or congenital defect. It is most commonly seen in older toy breed dogs.

Presenting Clinical Signs

• Cough, gagging, mucopurulent nasal discharge, ocular discharge, open mouth breathing, retching, sneezing

• Cachexia, change in voice, dyspnea, gagging, heat intolerance, intermittent “honking” cough, syncope

Examination Findings

• Bony swelling, pyrexia, lymphadenopathy, oral ulceration, ocular or neurological changes

• Cyanosis, enlarged tonsils, stertor, stridor

General

• History/clinical signs • Nasal examination

• History/clinical signs • Airway examination

Laboratory

• Cytology and culture: bacteria recognition and identification • Fungal culture: isolation and identification

• N/A

Imaging

• Radiographs, skull: ↑ fluid and bony changes (e.g., loss of bone detail and deviated septum)

• Radiographs, thoracic: narrowing or ballooning of tracheal diameter and ↑ R-sided cardiac size • Radiographs, cervical/pharyngeal: narrowing or ballooning of tracheal diameter

Procedures

• Rhinoscopy: foreign body and bony changes • Biopsy: bacteria or fungi

• Bronchoscopy: severity and small airway disease • Fluoroscopy: narrowing of tracheal diameter may be dynamic

General

• • • •

• Symptomatic • Surgery: application of intraluminal or extraluminal prostheses

Treatment

Diagnosis

Presentation

Disease

Supportive Fluid therapy Radiotherapy Surgery: nasal exploratory, rhinotomy, or turbinectomy

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Table 6.9 / Cardiopulmonary: Rhinitis/Sinusitis and Tracheal Collapse (Continued) Rhinitis/Sinusitis

Tracheal Collapse

Medication

• Antibiotics: cephalexin, trimethoprim-sulfa, and chloramphenical • Corticosteroids: prednisone • Fungicides: enilconazole, itraconazole, thiabendazole, or ketoconazole

• Antitussives: butorphanol, hydrocodone • Bronchodilators: aminophylline, theophylline, terbutaline, guaifenesin • Corticosteroids: prednisone

Nursing Care

• Airway humidification

• Intensive monitoring during and postoperative for signs of hypoxia

Patient Care

• Monitor for relapse of clinical signs

• Limit activity • Weight loss • Chest harness

Prevention/ Avoidance

• Vaccinate • Maintain good oral hygiene • Prevent exposure to bird feces (aspergillosis and cryptococcosis)

• Maintain proper weight control • Avoid extreme temperature and humidity changes

Complications

• Brain infection • Epistaxis

• Death from hypoxia (rare)

Prognosis

• Fair to good

• Good with uncomplicated surgery • Guarded with symptomatic treatment

• Serous nasal discharge is indicative of acute or allergic disease • Mucopurulent discharge suggests bacterial or fungal infection (infection may be only secondary to underlying neoplasia)

• Obtain both inspiratory and expiratory radiographs: tracheal collapse may be seen at any point during breathing

Notes

DERMATOLOGY Table 6.10 / Dermatology: Acne Disease

Definition

Presentation

6

Follow-Up

Treatment

Disease

220

Presenting Clinical Signs

Acne Canine

Feline

Chronic inflammatory disorder most often seen in short-coated breeds. It is often associated with superficial and deep pyoderma. It is typically found on the chin and lips of young animals.

Feline acne is often associated with the chin and lower lip. They may have a single episode or a continual lifelong problem. Poor grooming is thought to be one cause for this condition.

• Erythematous papules, swelling, exudate and scarring

• Comedones, erythema papules, serous crusts, swelling, and alopecia

SECTION THREE: DIAGNOSTIC SKILLS

Table 6.10 / Dermatology: Acne (Continued)

Follow-Up

Treatment

Diagnosis

Disease

Acne Canine

Feline

General

• Clinical signs

• Clinical signs

Laboratory

• Culture, bacterial: bacteria isolation and identification

• N/A

Imaging

• N/A

• N/A

Procedures

• Biopsy: to confirm diagnosis

• Biopsy: to confirm diagnosis

General

• Symptomatic • Skin treatment

• Symptomatic • Skin treatment

Medication

• Antibiotics: cephalexin, clavamox, clindamycin, erythromycin, cefpodoxime • Antibiotics (topical): mupirocin • Corticosteroids: prednisone or prednisolone • Medicated gels: pyoben • Medicated shampoo: benzoyl peroxide • Retinoids (topical): retin-A gel and tretinoin

• • • •

Nursing Care

• Treated as outpatient

• Treated as outpatient

Patient Care

• Prevent self-trauma: (e.g., rubbing of chin, chewing on bones that ↑ salivation). • Frequent cleaning/shampooing of chin • Warm compresses

• Shampoo 1–2 times weekly and then taper over a 2–3 week period. • Monitor PE and chemistry panel monthly with retinol.

Prevention/ Avoidance

• Maintenance lifelong treatment may be necessary.

• Maintenance lifelong treatment may be necessary. • Avoid the use of plastic feeding dishes.

Complications

• Deep pyoderma

• Deep pyoderma

Prognosis

• Excellent

• Excellent

• English Bulldog, Boxer, Doberman Pinscher, and Great Dane • Discourage owners from expressing the lesions, it can lead to massive inflammation.

• Discourage owners from expressing the lesions, it can lead to massive inflammation.

Notes

Antibiotics: clavamox or enrofloxacin Antibiotics (topical): mupirocin Medicated shampoo: benzoyl peroxide or sulfur–salicylic acid Retinoids (topical): retin-A gel and tretinoin

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6

221

Table 6.11 / Dermatology: Acral Lick Dermatitis, Atopy, and Flea Allergy Dermatitis Disease

Acral Lick Dermatitis (Lick Granuloma, Acral Pruritic Nodule)

Atopy

Flea Allergy Dermatitis (FAD)

Definition

Acral lick dermatitis is an area of a firm, raised, ulcerative, or thickened area that is usually located on the dorsal aspect of the carpus, metacarpus, tarsus, or metatarsus. The area may have a history of trauma, foreign body reaction, neoplasia, allergy, endocrinology, or others. The problem is typically made worse by the constant licking and chewing by the patient.

Animals that have formed allergies to normally innocuous inhaled substances such as pollen, grass, fleas, molds, and mites. This disease is the cause of a majority of dermatologic problems.

The antigens in the saliva of fleas are the cause of a hypersensitivity reaction called flea allergy dermatitis. It is the most common skin disease in most geographical areas, especially during the summer months. Ctenocephalides felis is the type of flea that usually infests both dogs and cats.

Presenting Clinical Signs

• Alopecia, excessive licking, chewing

• Pruritis and skin lesions • Canine: alopecia, edema, face rubbing, foot chewing, hyperpigmentation • Feline: alopecia, dermatitis, and miliary eczema

• Alopecia (tail base, dorsal lumbar region, caudal thighs, groin, abdomen, head and neck), broken hairs, chewing, dry hair, excoriations, hyperpigmentation, licking, pruritis, rolling, rubbing, scaling, scratching • Feline: alopecia (head and neck)

Examination Findings

• Firm, hyperpigmentation, raised, thickened, ulcerative

• Canine: otitis externa, recurrent pyoderma, seborrheic dermatitis • Feline: miliary eczema, eosinophilic granuloma complex

• Erythema, otitis externa, papules • Feline: lymphadenopathy, miliary eczema

General

• History/clinical signs

• History/clinical signs: seasonal

• History/clinical signs • Presence of fleas or flea dirt

Laboratory

• Skin scraping: bacteria, demodex, dermatophytosis • Culture, bacterial: bacteria isolation and identification • Biopsy, skin: neoplasia • Intradermal skin test: atopy

• CBC: eosinophilia (occasional) • Intradermal skin test: most reliable specific test • ELISA and RAST: ↑ values (nonspecific)

• CBC: hypereosinophilia (cats–v) • Intradermal skin test: + (reliable) • Serology: + serum IgE anti-flea antibody titer

Imaging

• Lower limb: neoplasia, radiopaque foreign body, bony proliferation, and some forms of trauma

• N/A

• N/A

Procedures

• Hypoallergenic test diet: food hypersensitivity

Diagnosis

Presentation

6

222

SECTION THREE: DIAGNOSTIC SKILLS

• Flea combing

Table 6.11 / Dermatology: Acral Lick Dermatitis, Atopy, and Flea Allergy Dermatitis (Continued) Acral Lick Dermatitis (Lick Granuloma, Acral Pruritic Nodule)

Atopy

Flea Allergy Dermatitis (FAD)

General

• Symptomatic • Laser ablation

• Symptomatic

• Symptomatic

Medication

• Antihistamines: chlorpheniramine and hydroxyzine HCl • Antibiotics: variable • Psychotropic drugs: clomopramine HCl, amitriptyline or fluoxetine HCl

• Antihistamines: chlorpheniramine, hydroxyzine and diphenhydramine • Corticosteroids: prednisone or methylprednisolone • Cyclosporine • Immunotherapy: SQ injection of increasing doses of offending allergen • Medicated shampoos • Psychotropic agents: amitriptyline, fluoxetine, barbiturates

• Antihistamines: diphenhydramine or chlorpheniramine • Antiparasitic: fipronil • Corticosteroids: triamcinolone • Fatty acid supplements • Insecticide: imidacloprid and selamectin • Insect growth regulator: lufenuron, pyriproxifen, methoprene

Follow-Up

Treatment

Disease

6

Nursing Care

• Treated as outpatient

• Treated as outpatient

• Treated as outpatient

Patient Care

• Monitor close for licking and chewing. • Check CBC, biochemistry, and ECG every 1–2 months for those receiving tricyclic antidepressants.

• Fatty acid supplementation • Frequent bathing to reduce pruritis • Exam patients 2–8 weeks following treatment, then every 3–12 months.

• Flea comb regularly.

Prevention/ Avoidance

• Determine underlying disease when possible.

• Avoid offending allergen.

• Maintain year around flea control: flea comb, monthly oral medication, and/or spot-on medication.

Complications

• Deep pyoderma

• Superficial pyoderma • Flea allergy dermatitis • Surface pyoderma

• Superficial or deep pyoderma • Acute moist dermatitis • Acral lick dermatitis

Prognosis

• Guarded (not life threatening) if no underlying disease is found and psychogenic causes are suspected

• Good if allergen is determined

• Excellent

• Elizabethan collars, foul-tasting medications and sprays, and bandages may be used to prevent licking and chewing. • Additional attention and exercise may help if psychogenic causes are suspected.

• Do not use penicillins or tetracyclines for treatment of superficial pyoderma. • Some type of treatment is usually needed for life. • It may take up to 6–12 months before results from immunotherapy are seen.

• A complete flea control plan includes treating the pet, other pets in-household, and indoor and outdoor environment. • Control may take 4–8 weeks to achieve. • With many new alternatives to flea control, dips, sprays, and flea collars should be the last choice for control. • Extra care should be taken when using insecticides to avoid overdose to animals and humans. • Flea-infested animals should also be checked for Dipylidium caninum.

Notes

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223

Table 6.12 / Dermatology: Food Hypersensitivity and Otitis Externa Food Hypersensitivity

Otitis Externa

Definition

Food hypersensitivities show symptoms induced by food or food additive ingestion in which there are demonstrable or highly suspected immunologic reactions.

Otitis externa is the inflammation of the soft tissue of the external ear canal. Its causes are often multifactorial, signifying a generalized dermatologic problem. It can be either a primary or a secondary disease, making it very frustrating and difficult to treat.

Presenting Clinical Signs

• Alopecia, diarrhea, flatulence, pruritis (feet, ears, face, neck, inguinal or axillary areas, perineum), seizures, vomiting

• Behavioral changes (irritable, aggression), foul odor, head shaking, head tilting, hearing loss, pain, foul odor, scratching, rubbing at ears

Examination Findings

• Erythematous, otitis externa, Malassezia dermatitis, papular rash

• Calcification/thickening of canal, debris, exudate, inflammation, swelling, ulceration

General

• History/clinical signs • Nonseasonal occurrence and partial or incomplete response to corticosteroids

• History/clinical signs • Otoscopic examination

Laboratory

• N/A

• N/A

Imaging

• N/A

• Radiographs, skull: only used in chronic cases to determine patency of ear canal and rule out otitis media

Procedures

• Intradermal skin testing: inconsistent findings • Hypoallergenic test diet or novel elimination diet trial

• Cytology: parasites, cells, bacteria, yeast, and fungi • Culture: bacteria recognition and identification • Intradermal skin tests: + results

General

• Symptomatic

• Symptomatic • Flush and dry ear canals; Tris-EDTA as pretreatment wash

Medication

• If any, dependent on clinical signs

• Antibiotics: cephalexin, trimethoprim-sulfa, enrofloxacin, clindamycin, clavamox, ciprofloxacin, difloxacin, cefpodoxime • Antibiotics (topical): enrofloxacin, tobramycin, silver sulfadiazine • Antifungals: ketoconazole, miconazole • Corticosteroids: prednisone • Ear cleaner • Parasiticides: ivermectin

Nursing Care

• Treated as outpatient

• Treated as outpatient

Patient Care

• Feed the restricted diet exclusively for 10–12 weeks. • Avoid flavored chew toys, bones, treats, vitamins and medications.

• Recheck ears frequently until resolved: do not treat prior to examination for better visibility.

Prevention/ Avoidance

• Restrict the feeding of hypersensitive foods.

• Clean ears regularly. • Thoroughly dry ears after swimming and bathing. • Lateral ear resection surgery

Complications

• Pruritis: by other sources

• Ruptured ear drum • Otitis media • Permanent ear canal changes: stenosis and calcification

Prognosis

• Good if offending food is determined

• Excellent if treated early

Presentation

Disease

Follow-Up

Treatment

Diagnosis

6

224

SECTION THREE: DIAGNOSTIC SKILLS

Table 6.12 / Dermatology: Food Hypersensitivity and Otitis Externa (Continued) Disease

Food Hypersensitivity

Otitis Externa

Notes

• The diet should consist of foods that the animal has not been previously exposed to (e.g., rice, potatoes, lamb) and without additives or preservatives. (See Table 3.2 Disease Nutritional Requirements, page 64.) • If no improvement, review other food sources and other forms of allergens (e.g., fleas and inhalant). • Corticosteroids should only be used with severe pruritis; otherwise, they may alter the results of the hypoallergenic diet test.

• Enough topical medication must be used to coat the entire ear canal for effectiveness, and then its use is tapered once infection is resolved. • Possible reasons for certain exudates: • Dark, dry, and granular: ear mite infection • Moist, yellow, and odiferous: bacterial infection • Brown and waxy: yeast infection • Yellow and waxy-to-oily: keratinization disorders • Use only warmed 0.9% saline to flush an ear canal with a ruptured tympanic membrane. • Plucking hair from within the ear canal may cause irritation and predisposes the animal to otitis externa.

6

Table 6.13 / Dermatology: Pyoderma Disease

Definition

Presentation

Presenting Clinical Signs

Examination Findings

Pyoderma Deep

Superficial (Superficial Bacterial Folliculitis)

Surface (Acute Moist Dermatitis [Hot Spots], Skinfold Dermatitis)

Deep pyoderma extends into the dermis and, in severe cases, into the subcutaneous tissue. This bacterial skin infection has many different forms, two of the most common being folliculitis and furunculosis. It is almost always secondary to another disease process.

The epidermis is the target of a bacterial infection with superficial pyoderma. It can manifest itself in 2 ways: penetrating the stratus corneum (impetigo) or invading the hair follicles (folliculitis).

Self-trauma and deep skinfolds are the most common reasons for surface pyoderma. This is due to a colony of bacteria on the surface of the epidermis only, without invading the stratum corneum or hair follicles. Acute moist dermatitis (hot spots) and skinfold dermatitis are the two distinct forms of surface pyoderma.

• Alopecia, anorexia, depression, peripheral lymphadenopathy, and fever • Pustules: inguinal, ventral abdominal, and axillary areas extending to the whole body • Erythematous, painful, pruritic skin • Exudate and crust formation, drainage tracts, and hemorrhagic bullae

• Dull haircoat, excessive shedding, scales • Impetigo: pustules (inguinal and ventral abdominal area, esp. young animals), patchy alopecia • Folliculitis: pustules (inguinal, ventral abdominal, axillary areas)

• Biting, licking, and rubbing by patient Acute Moist Dermatitis • Alopecia, thin exudate layer, erythema, surrounded by matted hairs and thickened skin with abrasion Skinfold Pyoderma • Inflammation, exudate, fetid, alopecia, and erythema

• Folliculitis: epidermal collarettes (“bull’seye” lesions), erythema, pruritic skin

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225

Table 6.13 / Dermatology: Pyoderma (Continued) Disease

Superficial (Superficial Bacterial Folliculitis)

Surface (Acute Moist Dermatitis [Hot Spots], Skinfold Dermatitis)

General

• History/clinical signs

• History/clinical signs

• History/clinical signs • Self-trauma, environmental irritant, or any pruritic skin

Laboratory

• • • • • • •

• Cytology: neutrophils and bacteria • Skin scrapings: ectoparasites • Culture: bacteria isolation and identification • Skin biopsy: to confirm folliculitis

• Culture: bacteria isolation and identification • Skin biopsy: nonfollicular subcorneal pustules, suppurative inflammation with sepsis • Skin Scraping: cocci in clusters on squamous epithelial cells or budding yeast

Imaging

• N/A

• N/A

• N/A

Procedures

• Skin scraping and biopsy

• Skin scraping and biopsy

• N/A

General

• Symptomatic • Fluid therapy (severe cases)

• Symptomatic

• Symptomatic • Wound management

Medication

• Antibiotics: variable • Medicated shampoos

• Antibiotics: variable • Medicated shampoos: antibacterial

• Antibiotics (oral and/or topical): variable • Corticosteroids (topical): panalog cream and neopredef powder

Nursing Care

• Clip haircoat on long-coated breeds

• Treated as outpatient

• Treated as outpatient

Patient Care

• Bathe twice daily for 1–2 weeks then 1–2 times weekly. • Whirlpool baths • Provide a high-quality diet. • Supplement with essential fatty acids. • Padded bedding to ease pressure point pyoderma

• • • •

• Maintain a clean and dry wound • Prevent self-trauma: restraint, collars, etc.

Prevention/ Avoidance

• Determine the underlying cause. • Bathe regularly with appropriate shampoo.

• Determine the underlying cause. • Bath with appropriate shampoo, especially after swimming.

• Determine the underlying cause. • Clean and dry the skinfolds routinely with astringents.

Complications

• Bacteremia or septicemia • Scarring

• Deep pyoderma • Recurrence

• Superficial or deep pyoderma

Prognosis

• Excellent if underlying cause is determined

• Excellent

• Excellent

• German Shepard

• If persistent pruritis, ectoparasitism or allergy may be present as underlying etiology.

• Cocker Spaniel, Springer Spaniel, Saint Bernard, Irish Setter, Shar pei, Basset Hound, Bulldog, Boston Terrier, and Pug • Corrective surgery may be performed on chronically infected skinfolds.

Diagnosis

Deep

Follow-Up

Treatment

6

Notes

226

Pyoderma

CBC: leukocytosis with a left shift (v) Chemistry panel: ↑ globulin (v) Cytology: neutrophils, macrophages, and bacteria Skin scrapings: ectoparasites Blood culture: bacteria Culture: bacteria recognition and identification Skin biopsy: to confirm folliculitis, perifolliculitis, or furunculosis

SECTION THREE: DIAGNOSTIC SKILLS

Bathe 2–3 times weekly for 2–3 weeks. Prevent self-trauma. Provide a high-quality diet. Supplement with essential fatty acids.

ENDOCRINOLOGY AND REPRODUCTION Table 6.14 / Endocrinology and Reproduction: Abortion and Diabetes Insipidus Abortion

Diabetes Insipidus

Definition

An abortion is the termination of a pregnancy. It may be the result of difficulties with the mother, fetus, or placenta. Exposures to toxins or infections in the dam are well documented.

Diabetes insipidus is a disorder of water metabolism due to a deficiency of antidiuretic hormone (ADH) caused by either a lack of release of ADH or renal tubular insensitivity to ADH.

Presenting Clinical Signs

• Anorexia, depression, lethargy, vomiting, and diarrhea • Early gestation: vaginal discharge, fetid and purulent • Late gestation: restlessness and abdominal contractions

• Blindness, disorientation, incontinence, nocturia, PU/PD, seizures, weight loss

Examination Findings

• Disappearance of previously documented (e.g., palpation, ultrasound, radiogragh) fetuses

• Dehydration

General

• History/clinical signs • Observe for any systemic signs of illness

• Clinical signs

Laboratory

• Bacterial culture: bacteria isolation and identification • RAST or AGID: Brucella canis

• Chemistry panel: ↑ sodium • Urinalysis: ↑ protein (v), ↓ specific gravity: <1.010 • Abrupt or gradual water deprivation test: UA specific gravity of <1.025 μg/dL • ADH response test: failure to concentrate urine after exogenous ADH administration

Imaging

• Radiographs, abdominal: retained fetuses • Ultrasound: uterine pathology and retained fetuses

• Nuclear imaging and CT: identify pituitary or hypothalamic lesion

Procedures

• Necropsy of dead fetuses

General

• Symptomatic • Fluid therapy • Surgery: cesarean section

• Symptomatic

Medication

• Antibiotics: variable • Prostaglandin

• ADH supplement: vasopressin, pitressin tannate

Nursing Care

• Postparturition or postoperative nursing care

• Free access to water

Patient Care

• Physical examination 7–14 after treatment

• Free access to water • Sodium-restricted diet

Prevention/ Avoidance

• OVH

• Avoid circumstances that might markedly increase water loss

Follow-Up

Treatment

Diagnosis

Presentation

Disease

6

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227

Table 6.14 / Endocrinology and Reproduction: Abortion and Diabetes Insipidus (Continued) Abortion

Diabetes Insipidus

Complications

• • • • • • •

• Primary disease

Prognosis

• Excellent if treated early

• Very good prognosis with lack of release of ADH • Guarded prognosis with renal insensitivity to ADH

• In the first trimester, it is very difficult to distinguish between abortion and infertility. • Aborted fetuses or placenta may be infectious; isolate animal from all other dogs, pups, and humans.

• Water deprivation test is contraindicated in dehydrated animals.

Follow-Up

Disease

Notes

6

Death Infertility Peritonitis Pyometra Sepsis Shock Uterine rupture

Table 6.15 / Endocrinology and Reproduction: Diabetes Mellitus Diabetes Mellitus

Definition

A chronic disorder of carbohydrate metabolism, characterized by hyperglycemia and glucosuria and resulting from inadequate production or utilization of insulin Type 1: insulin-dependent (low to absent secretory ability) Type 2: non–insulin-dependent (inadequate or delayed insulin secretion or peripheral tissue insensitivity to insulin)

Diagnosis

Presentation

Disease

228

Presenting Clinical Signs

• PU/PD, polyphagia, and weight loss • Later stages: anorexia, lethargy, oily hair coat, dorsal muscle wasting, depression, and vomiting

Examination Findings

• Hepatomegaly, cataracts (canine), plantigrade stance (feline)

General

• History/clinical signs

Laboratory

• CBC: eosinophilia and lymphocytosis (v), ↑ PCV/TP, mild nonregenerative anemia, Heinz bodies • Chemistry panel: ↑ glucose (>200 mg/dL in dogs: >250 mg/dL in cats), cholesterol, sodium, phosphate, alk phos, ALT, AST, and ↓ potassium and metabolic acidosis

Imaging

• Radiographs, thoracic: microcardia and hypoperfusion of lungs • Ultrasound: pancreatic and liver pathology

Procedures

• Liver biopsy (e.g., jaundiced patients)

SECTION THREE: DIAGNOSTIC SKILLS

Table 6.15 / Endocrinology and Reproduction: Diabetes Mellitus (Continued)

Follow-Up

Treatment

Disease

Diabetes Mellitus

General

• Supportive • Fluid therapy

Medication

• Insulin: PZI, NPH, glargine, Vetsulin, caninsulin • Oral hypoglycemics: glipizide, metformin, troglitazone, acarbose

Nursing Care

• Free access to water • Try to mimic the same feeding schedule used at home. • Low stress environment

Patient Care

• • • •

Maintain a regimented feeding and medication schedule. Monitor for signs of iatrogenic hypoglycemia, PU/PD, appetite, and body weight. Provide consistent amount of exercise every day to prevent fluctuations in insulin requirements. Monitor serial BGs (initially every few weeks and then once regulated, every few months) or monitor serum fructosamine or glycosylated hemoglobin.

Prevention/Avoidance

• Prevent or correct obesity. • Avoid unnecessary use of corticosteroids or megesterol acetate.

Complications

• • • • •

Prognosis

• Cats may recover but may relapse later. • Dogs have permanent disease. • Normal life span is expected with treatment.

Notes

6

Secondary infections Anemia and hemoglobinemia with severe hypophosphatemia Cataracts (canine) Diabetic neuropathy (feline) Seizures or coma

• Meals should coincide with the administration of insulin. • Feed a canned low-carbohydrate and high-protein diet twice daily (esp. feline). • Patients scheduled for surgery: NPO after 12 AM, give 1/2 the normal dose of insulin the morning of surgery, monitor blood glucose levels, and administer R insulin if needed following the surgery maintain the patient on a 5% dextrose IV drip until food intake has resumed. • Keeshond, Puli, Miniature Pinscher, and Cairn Terrier

Note: See Insulin Therapy, Skill Boxes 8.14, 8.15, and 8.16, page 357.

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229

Table 6.16 / Endocrinology and Reproduction: Dystocia and Eclampsia Dystociaa

Eclampsia (Puerperal tetany)

Definition

Dystocia results from abnormalities associated with parturition. They are due to either primary or secondary uterine inertia. Primary uterine inertia is the failure of uterine contractions sufficient to deliver. Secondary uterine inertia is fetal obstruction due to large pups, narrow birth canal, abnormal pup position, etc.

Eclampsia can be a life-threatening condition often seen 1–4 weeks postpartum. It is due to extremely low serum ionized calcium levels.

Clinical Signs

• Abnormal vaginal discharge, active straining for >45 minutes, crying and biting at vulvar area, intermittent weak contractions for >2 hours, presence of fetal membrane in the vulva for >15 minutes, resting phase for >4–6 hours without straining

• Ataxia, convulsions, drooling, muscle tremors, nervousness, pacing, panting, restlessness, salivation, seizures, stiff gait, tachypnea, tremors, whining

Examination Findings

• Vaginal stenosis

• Dilated pupils, ↓ pupillary light response, pyrexia, tachycardia, tetany

General

• History/clinical signs • Prolonged gestation: >72 days from the first mating

• History/clinical signs

Laboratory

• CBC: ↑ PCV/TP and ↓ glucose and calcium

• Chemistry panel: ↓ calcium (≤7 mg/dL) and glucose (rare)

Imaging

• Radiographs, abdominal: fetal death characterized by intrafetal gas patterns, collapsed spinal cord, overlapping of the skull bones or pup in the birth canal • Ultrasound: uterine pathology and fetal distress (↓ heart rate and fetal bowel movements)

• N/A

Procedures

• Vaginal examination

• ECG: prolonged QT interval, bradycardia, tachycardia or VPCs

General

• • • •

• Symptomatic

Medication

• Anesthesia: isoflurane or reversible induction agents • Ecbolic agents: oxytocin, calcium gluconate, ergonovine maleate or dextrose • Tranquilizer: acepromazine

• Calcium supplementation: calcium gluconate • Tranquilizers: diazepam

Nursing Care

• Postparturition or standard postoperative

• Calcium administration often leads to vomiting, which will subside. • Cold water baths and enemas • Hand-raise puppies until crisis is over.

Patient Care

• Postparturition care • Monitor growth and nursing habits of the neonates.

• Monitor calcium levels • Supplement oral calcium throughout lactation

Prevention/ Avoidance

• OVH • Scheduled cesarean section

• Do not supplement with calcium during gestation. • OVH

Presentation

Disease

Follow-Up

Treatment

Diagnosis

6

230

Symptomatic Fluid therapy Manual manipulation via vagina Surgery: emergency cesarean section

SECTION THREE: DIAGNOSTIC SKILLS

Table 6.16 / Endocrinology and Reproduction: Dystocia and Eclampsia (Continued) Dystociaa

Eclampsia (Puerperal tetany)

Complications

• Maternal or fetal death • ↑ risk in future pregnancies • Neonate stuck in birth canal

• Cerebral edema • Death

Prognosis

• Excellent if discovered early

• Good with immediate treatment • Poor with delayed treatment

• Rule out obstructive dystocia before administering ecbolics agents. • Welsh Corgi and brachycephalic breeds tend to have a congenitally small pelvis, and the pups tend to have large heads and shoulders.

• Response to treatment is rapid; therefore, treat if the diagnosis is suspected while lab confirmation is pending. • Probable reoccurrence with subsequent litters

Follow-Up

Disease

Notes

See Table 2.4, Normal Parturition of Canines and Felines and Skill Box 7.4 Neonatal Resuscitation Post-Cesarean, page 317.

6 Table 6.17 / Endocrinology and Reproduction: Hyperadrenocorticism and Hyperparathyroidism Hyperadrenocorticism (HAC, Canine Cushing’s Syndrome)

Hyperparathyroidism

Definition

Hyperadrenocorticism is most commonly found in canines middle to old age. It is caused by the excessive secretion of cortisol by the adrenal glands. The excess glucocorticoid comes from (1) excessive secretion of ACTH from a pituitary microadenoma or (2) an adrenocortical tumor. Excessive administration of corticosteroids can also result in iatrogenic HAC, a separate syndrome.

The disease results from excessive secretion of the parathyroid hormone (PTH). This can be caused by an adenoma, carcinoma, or hyperplasia of the parathyroid gland.

Clinical Signs

• Behavior changes, bilaterally symmetric alopecia, circling, dull haircoat, dyspnea, excessive panting, infertility, pendulous, distended or pot-bellied abdomen, polyphagia, PU/PD, recurrent skin infections, seizures

• Anorexia, ataxia, constipation, depression, facial swelling, lethargy, muscle tremors, PU/PD, seizures, shivering, stiff gait, twitching, vomiting, weakness

Examination Findings

• Muscle and testicular atrophy, thin skin with hyperpigmentation and ↑ fragility (esp. feline)

• Cataracts, tachycardia

General

• History: exogenous glucocorticoid use • Clinical signs

• Clinical signs • Palpation of a parathyroid gland (feline)

Laboratory

• CBC: steroid leukogram and mild erythrocytosis (v) • Chemistry panel: ↑ alk phos, cholesterol, ALT and glucose (v) • Urinalysis: ↑ protein, blood, bacteria, WBCs, cortisol-to-creatinine ratio (>35), and ↓ specific gravity: <1.020 • ACTH stimulation test: to diagnose type, >20 μg/dL with endogenous HAC, blunted or no response iatrogenic HAC • Low dose dexamethasone suppression test: to confirm diagnosis, >1 μg/dL during 8 hour test • High dose dexamethasone suppression test: to differentiate type, <1.5 μg/dL with pituitary dependent HAC and >1.5 μg/dL with adrenocortical neoplasia • Endogenous plasma ACTH concentration: to differentiate type, >40 pg/mL with pituitary dependent HAC and <20 pg/mL with adrenocortical tumors

• • • •

Presentation

Disease

Diagnosis

a

Chemistry panel: ↑ calcium, ALT, alk phos, ↓ phosphorus Urinalysis: ↓ specific gravity Serum ionized calcium: ↑ values Serum PTH concentration: ↑ values

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231

Table 6.17 / Endocrinology and Reproduction: Hyperadrenocorticism and Hyperparathyroidism (Continued) Hyperadrenocorticism (HAC, Canine Cushing’s Syndrome)

Hyperparathyroidism

Imaging

• • • •

• Radiographs, skeletal: generalized osteopenia, ↑ bone resorption (alveolar bone of the jaw) and cyst-like areas in the bone • Ultrasound: visualization of the parathyroid gland, urolithiasis, and renal abnormalities

Procedures

• N/A

• ECG: premature ventricular complexes

General

• Symptomatic • Radiation therapy: pituitary macroadenoma or marcocarcinoma • Surgery: removal of adrenal tumor, removal of pituitary (hypophysectomy)

• Symptomatic • Fluid therapy • Surgery: removal of the parathyroid gland adenoma

Medication

• • • •

• Diuretics: furosemide • Calcitriol (postoperative for transient iatrogenic hypocalcemia)

Nursing Care

• Treated as outpatient

• Standard postoperative

Patient Care

• Monitor for reoccurrence of previous clinical signs • Perform an ACTH response test 5–10 days initiation of medication (except L-deprenyl) then every 3–6 months • Monitor for inappetance, severe decreased water consumption, attitude, activity, vomiting, or diarrhea relating to the medication

• Monitor serum calcium 1–2 times daily for 1 week postoperative • Diet of ↑ phosphorus and ↓ calcium

Prevention/ Avoidance

• N/A

• N/A

Complications

• • • • • • •

• Hypocalcemia (iatrogenic) • Renal failure

Prognosis

• Guarded due to the number of complications associated with this disease

• Excellent with proper treatment • Poor with associated renal disease

• Easy cutaneous bruising (canine), venipuncture should be perform with extra care • Most commonly seen in Poodle, Dachshund, Boston Terrier, and Boxer

• This is the only condition that causes ↓ phosphorous and ↑ calcium, • Keeshond, German Shepard, Norwegian Elkhound, and Siamese cat

Follow-Up

6

Treatment

Diagnosis

Disease

Notes

232

Radiographs, thoracic: mineralization of bronchial walls Radiographs, abdominal: adrenal tumors and hepatomegaly Ultrasound: ↑ liver and adrenal glands CT: visualization of pituitary tumors and possibly pituitary microadenomas (radiographs and ultrasounds can be used, but are not as accurate)

Corticosteroids: prednisone or prednisolone Ketoconazole L-Deprenyl Mitotane, trilostane

Thromboembolism Congestive heart failure Hypertension Recurrence of clinical signs Progression of CNS signs Infection: skin and urinary Diabetes mellitus

SECTION THREE: DIAGNOSTIC SKILLS

Table 6.18 / Endocrinology and Reproduction: Hyperthyroidism and Hypoadrenocorticism Hyperthyroidism (Feline)

Hypoadrenocorticism (Addison’s Disease)

Definition

A multisystemic metabolic disorder most commonly seen in middleaged to old felines. It is caused by an excessive amount of circulating thyroid hormone. The disease causes an increased basal metabolic rate, which in turn causes the disease’s clinical signs.

Hypoadrenocorticism is a disease of the adrenal gland resulting in a deficiency of glucocorticoid and/or mineralcorticoid secretion from the adrenal cortex. The cause is often thought to be idiopathic or sometimes due to infection, hemorrhagic infarctions, metastatic neoplasia, trauma, and amyloidosis. Mostly seen in young to middleaged female dogs.

Clinical Signs

• ↑ Appetite, behavioral changes, diarrhea, dyspnea, excessive shedding and matting, heat intolerance, hyperexcitability, hyperventilation, panting, PU/PD, restlessness, tachypnea, unkept haircoat, vomiting, weakness, weight loss

• Intermittent anorexia, collapse, depression, diarrhea, lethargy, melena, muscle weakness, polyuria, PU/PD, shivering, vomiting, weight loss

Examination Findings

• Arrhythmia, enlargement of 1 or both thyroid glands, gallop, lymphadenopathy, pallor, systolic murmur, tachycardia

• Arrhythmias, dehydration, progressing to bradycardia, shock, weak pulses

General

• History/clinical signs • Palpation of thyroid gland(s)

• History/clinical signs

Laboratory

• CBC: erythrocytosis (v), mature leukocytosis, eosinopenia, monocytosis, ↑ PCV, MCV, Heinz bodies (v) • Chemistry panel: ↑ ALT, AST, alk phos, BUN, creatinine, calcium, glucose, phosphorus, bilirubin, lactate • Basal serum thyroid hormone concentration: >4 μg/dL • Free T4 by equilibrium analysis: ↑ value • T3 suppression test: >1.5 μg/dL • TRH response test: little to no ↑ in serum T4 • TLI: ↓ TSH

• CBC: normocytic, normochromic nonregenerative anemia • Chemistry panel: ↑ ALT, AST, calcium, potassium, creatinine, BUN and ↓ phosphorus, sodium, chloride, cholesterol, glucose • Urinalysis: ↑ ketones, glucose, ↓ specific gravity: <1.030 • ACTH stimulation test, primary hypoadrenocorticism is <1 μg/dL • Plasma concentration of ACTH: primary is >500 pg/mL and secondary is <20 pg/mL • Plasma aldosterone: ↓ value • Sodium : potassium ratio: <27 : 1

Imaging

• Radiographs, thoracic: cardiomegaly, pulmonary edema, valentineshaped heart • Ultrasound, abdominal: underlying renal disease • Echocardiography: atrial and LV dilation, hypercontractility • Thyroid pertechnetate scan: + thyroid radioisotope

• Radiographs, abdominal: cystic or renal calculi, cholecystitis, and pancreatitis

Procedures

• ECG: atrial fibrillation, APCs, VPCs, tachycardia • Blood pressure: hypertension

• ECG: peaking of T waves, prolonged P-R waves until P wave ultimately disappears, QRS complex widens, and R-R intervals become irregular

Diagnosis

Presentation

Disease

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6

Table 6.18 / Endocrinology and Reproduction: Hyperthyroidism and Hypoadrenocorticism (Continued)

Treatment

Disease

Follow-Up

6

Hyperthyroidism (Feline)

Hypoadrenocorticism (Addison’s Disease)

General

• Symptomatic • Radioiodine therapy • Surgery: thyroidectomy

• Supportive • Fluid therapy (acute cases)

Medication

• β-Adrenergic blocking drugs • Antiarrythmics: propranolol • Antithyroid: methimazole, carbimazole, ipodate

• Corticosteroids: prednisolone sodium succinate, dexamethasone, prednisone • Mineralcorticoids: DOCP, fludrocortisones, hydrocortisone hemisuccinate, hydrocortisone phosphate • Calcium gluconate • Sodium bicarbonate

Nursing Care

• Treated as outpatient

• Treated as outpatient

Patient Care

• Monitor CBC, BUN, creatinine, and serum T4 every 2–4 weeks during first 3 months of methimazole treatment. • Monitor serum T4 the first week and then every 3–6 months after thyroidectomy. • Monitor T4 the second week and then every 3–6 months after radioiodine therapy.

• Monitor electrolytes weekly until stabilized. • Monitor electrolytes, BUN and creatinine monthly for 3 months, then every 3–12 months.

Prevention/ Avoidance

• N/A

• N/A

Complications

• • • • • •

• PU/PD from medication

Prognosis

• Excellent with treatment • Poor with thyroid carcinoma

• Good to excellent with proper diagnosis and treatment • Poor prognosis with tumors causing the disease

• Clinical signs are expected to completely resolve with proper treatment. • Radioiodine therapy is the best choice of treatment to cure the disease. • Renal disease may become apparent once euthyroidism is established.

• Most commonly seen in female dogs <7 years old. • Glucocorticoids (e.g., prednisolone) need to be ↑ during times of stress such as travel, hospitalization, and surgery. • Great Dane, Rottweiler, Portuguese Water Spaniel, West Highland White Terrier, Wheaten Terrier, and Standard Poodle

Notes

234

Congestive heart failure Dehydration Diarrhea Hypothyroidism (iatrogenic) Renal damage Retinal detachment

SECTION THREE: DIAGNOSTIC SKILLS

Table 6.19 / Endocrinology and Reproduction: Hypoparathyroidism, Hypothyroidism, and Mastitis Hypoparathyroidism

Hypothyroidism (Canine)

Mastitis

Definition

Hypoparathyroidism is a deficiency in the secretion of the parathyroid hormone. This condition is most commonly seen in dogs as naturally occurring and typically following thyroidectomy in cats.

Hypothyroidism is the most commonly diagnosed endocrine disease in the dog. A condition that results from inadequate production and release of T4. Caused by either destruction of the thyroid gland or impaired secretion of TSH by the pituitary gland.

Mastitis is a bacterial infection of one or more of the lactating glands. Seen in the postpartum dam and queen.

Clinical Signs

• Anorexia, ataxia, depression, diarrhea, listlessness, muscle spasms, nervousness, panting, rigid limb extension, seizures, stiff gait, tremors, twitching, vomiting, weight loss

• Abortion, anestrus, cold intolerance, exercise intolerance, infertility, lethargy, mental dullness, muscle weakness, weight gain

• Anorexia, cachexia, depression, lethargy, mammary gland abscess • Neglected, bloated, crying, restless, failure to thrive neonates

Examination Findings

• Cataracts, tachycardia, weak pulses

• Bradycardia, hyperpigmentation, impaired myocardial contractility, myxedema, neuropathies, pyodermas, testicular atrophy • Bilaterally symmetrical nonpruritic alopecia on ventral and lateral trunk, caudal thighs, dorsal tail, dorsal nose and ventral neck

• Dehydration, pyrexia • Mammary gland(s): firm, swollen, warm, painful, purulent or hemorrhagic discharge

General

• Clinical signs

• Clinical signs

• History/clinical signs

Laboratory

• Chemistry panel: ↑ phosphorus and ↓ calcium • Serum PTH concentration: ↓ value

• CBC: mild normocytic, normochromic, nonregenerative anemia • Chemistry panel: ↑ cholesterol, ALT, AST, SAP, CK, ↓ calcium • Basal serum T4 levels: <1.0 μg/dL • Serum TSH concentration: ↑ value • Free T4 by equilibrium analysis: ↓ value

• CBC: leukocytosis with left shift or leukopenia with sepsis and ↑ PCV (v) • Chemistry panel: ↑ TP and BUN • Cytology and culture, milk: neutrophils, macrophages, RBCs, bacteria isolation and identification

Imaging

• N/A

• N/A

• N/A

Procedures

• ECG: prolongation of QT and ST segments, deep wide T waves, and tachyarrhythmias

• N/A

• N/A

General

• Supportive • Fluid therapy

• Symptomatic

• Supportive • Fluid therapy • Surgery: lance, debride, drain placement of infected glands

Medication

• Calcium supplementation: calcium gluconate, calcium lactate, calcium carbonate • Vitamin D supplementation: vitamin D, hytakerol, calcitriol

• Sodium levothyroxine

• Antibiotics: variable, based on milk pH

Treatment

Diagnosis

Presentation

Disease

CHAPTER 6 / GENERAL MEDICINE

235

6

Table 6.19 / Endocrinology and Reproduction: Hypoparathyroidism, Hypothyroidism, and Mastitis (Continued)

6

Follow-Up

Treatment

Disease

Hypoparathyroidism

Hypothyroidism (Canine)

Mastitis

Nursing Care

• Treated as outpatient

• Treated as outpatient

• Hand raise puppies or find a surrogate dam if glands are necrotic and need surgical care. • Alternate cold and warm compress and manually milk glands several times a day

Patient Care

• Check serum calcium weekly for 1 month, monthly for 6 months, then every 2–4 months. • Diet of ↑ calcium and ↓ phosphorus

• Check serum T4 levels after 1 month of therapy, then every 6–12 months.

• Same as above • Monitor the growth and feeding habits of the neonates.

Prevention/ Avoidance

• N/A

• N/A

• Clean environment • Clip toenails of neonates. • Shave hair around mammary glands.

Complications

• Hypercalcemia (iatrogenic) • Renal disease

• Thyrotoxicosis from administration of high does of L-thyroxine

• Abscessed gland • Hand-raising of neonates

Prognosis

• Excellent with close monitoring of calcium levels

• Excellent with proper treatment • Poor if disease is due to a tumor of the thyroid gland

• Good with prompt treatment

• Check albumin level as it is the most common cause for pseudo-hypocalcemia. • Felines with transient hypoparathyroidism postthyroidectomy typically regain normal function by 4–6 months • Toy Poodle, Miniature Schnauzer, German Shepard, Labrador Retreiver, and Scottish Terrier

• Failure of clinical signs to significantly improve within 3 months may be due to an incorrect diagnosis • Improvement should be seen within 1–2 weeks after initiating treatment (e.g., mostly behavior and appetite). • Serum T4 levels should be checked 4–6 hours post administration of L-thyroxine. • Treatment is lifelong. • Golden Retriever, Doberman Pinscher, Irish Setter, Great Dane, Airedale Terrier, Old English Sheepdog, Miniature Schnauzer, Cocker Spaniel, Poodle, and Boxer

• Avoid antibiotics that may be passed in the milk and cause deleterious effects to the neonates.

Notes

236

SECTION THREE: DIAGNOSTIC SKILLS

Table 6.20 / Endocrinology and Reproduction: Pregnancy and Pyometra Disease

Pyometra may be seen in both dogs and cats following estrus or progesterone administration by 1–2 months. It is caused by a hormonal change in the uterus that allows for secondary infections and is seen with either an open cervix or closed cervix.

Clinical Signs

• Enlarged abdomen, mammary gland development and lactation, nesting instinct

• Anorexia, depression, lethargy, depression, diarrhea, vomiting • Open-cervix pyometra: mild systemic signs, PU/PD, vaginal discharge (purulent, blood, mucus) • Closed-cervix pyometra: collapse, more severe systemic signs

Examination Findings

• Documented fetuses (e.g., palpation, ultrasonography, radiogragh)

• Abdominal distention, enlarged uterus, hypothermia, septicemia, shock

General

• History/clinical signs • Abdominal palpation: 25–36 days after breeding (dogs) and 21–28 days after breeding (cats)

• History/clinical signs

Laboratory

• Chemistry panel: ↑ relaxin and progesterone levels

• CBC: neutrophilia with a left shift and mild nonregenerative anemia • Chemistry panel: ↑ globulin, protein, ALT, ALP, azotemia (v) and electrolyte imbalances • Urinalysis: ↑ protein and isothenuric • Cytology and culture: bacteria isolation and identification

Imaging

• Radiographs, abdominal: fetal skeletal calcification ≥42 days of gestation

• Radiographs, abdominal: enlarged or ruptured uterus and peritonitis • Ultrasonography: differentiate pyometra from pregnancy, intraluminal uterine contents, uterine wall thickened

Procedures

• Ultrasound: 16 days of gestation

• Vaginoscopy: determine site of origin of purulent discharge

General

• N/A

• • • •

Medication

• N/A

• Antibiotics: cephalothin, ampicillin or enrofloxacin • Prostaglandin F2α (PGF2α)

Nursing Care

• N/A

• Standard postoperative

Diagnosis Treatment

Pyometra

Pregnancy is the condition of carrying a developing embryo(s) in the uterus. Parturition consists of 3 stages. Stage 1 is characterized by restlessness, anxiety, nesting behavior, and shivering and can last 6– 12 hours. Stage 2 is the actual delivery of the fetus. There are visible contractions and the first fetus should be delivered within 1–2 hours from the onset of stage 2. There may be a resting period for up to 4 hours after the delivery of a fetus. Stage 3 is the expulsion of the placenta typically following the deliver of each fetus.

Definition

Presentation

Pregnancy

Symptomatic Fluid therapy OVH with abdominal lavage Medical management

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237

6

Table 6.20 / Endocrinology and Reproduction: Pregnancy and Pyometra (Continued)

Follow-Up

Disease

6

Pregnancy

Pyometra

Patient Care

• Provide adequate nutrition throughout pregnancy. • Provide a quiet safe place for the dam/queen to deliver. • Monitor parturition to become aware of any complications.

• Reexam medical managed pyometra cases 1 week after initiation of treatment. • Monitor progesterone levels 1 week after discontinuing treatment. • Vaginal discharge may be seen for 4 weeks post treatment.

Prevention/ Avoidance

• OVH • Supervision

• OVH

Complications

• • • •

• • • • •

Prognosis

• Excellent with proper prenatal care

• Good with OVH and no abdominal contamination • Guarded with medical management of closed pyometra

• The length of gestation is 63 days from ovulation but may extend from 56 to 72 days. • A transient temperature drop occurs within 24 hours of the onset of parturition. • A normal fetal heart rate is twice that of the mother.

• Do not perform cystocentesis when pyometra is suspected due to friable uterus and possible contamination of abdomen. • Diluting PGE2α with 1 : 1 sterile saline and walking an animal for 30 minutes after giving the injection may ↓ side effects.

Notes

Dystocia Retained fetuses or placenta Eclampsia Mastitis

Estrus sooner after treatment PGF2α side effects Recurrent pyometra with medical management necessary Sepsis and peritonitis Uterine rupture

GASTROENTEROLOGY Table 6.21 / Gastroenterology: Anal Sac Disease, Cholangitis, and Cholangiohepatitis Anal Sac Disease

Cholangitis and Cholangiohepatitis

Definition

This is the most common disease of the anal area in small animals, especially dogs. It is the impaction, inflammation, infection, abscess, and/or rupture of the anal gland(s).

Cholangitis is inflammation confined to the bile ducts. Cholangiohepatitis is the inflammation of the bile ducts and adjacent hepatocytes. The inflammatory infiltrates are either supprative (S), most commonly seen in younger cats, or nonsuppurative (NS), mostly seen in older cats.

Clinical Signs

• Behavior change, biting, chewing, discomfort in sitting, licking, malodorous, painful defecation, rubbing at perianal area, scooting, tail chasing, tenesmus

• Anorexia, depression, diarrhea, lethargy, vomiting, weight loss

Examination Findings

• Perianal discharge, swollen anal glands

• Abdominal pain, ascites, dehydration, generalized lymphadenopathy (rare), hepatomegaly (v), pyrexia, jaundice

Presentation

Disease

238

SECTION THREE: DIAGNOSTIC SKILLS

Table 6.21 / Gastroenterology: Anal Sac Disease, Cholangitis, and Cholangiohepatitis (Continued) Anal Sac Disease

Cholangitis and Cholangiohepatitis

General

• Clinical signs • Palpation of the anal glands

• History/clinical signs

Laboratory

• Cytology, exudate/secretion: WBCs and bacteria • Culture: bacteria isolation and identification

• CBC: mild nonregenerative anemia and neutrophilia with a left shift • Chemistry panel: ↑ bilirubin, ammonia, ALT, AST, ALP, GGT, globulin, ↓ albumin and BUN • Urinalysis: ↓ bilirubin • Bile acid concentrations: ↑ values • Coagulation profile: prolonged • Biopsy: • S: ↑ neutrophils, intrahepatic • NS: lymphocytic portal infiltrates • Culture, bile: bacteria isolation and identification

Follow-Up

Treatment

Diagnosis

Disease

6

Imaging

• N/A

Procedures

• N/A

General

• Expression of glands • Duct cannulation and irrigation • Surgery: anal sacculectomy

• Supportive • Fluid therapy • Laparotomy to relieve obstruction

Medication

• Antibiotics (systemic): chloramphenicol, penicillin, or aminoglycosides • Antibiotics (topical): panalog

• • • •

Nursing Care

• Treated as outpatient • Standard postoperative if surgery

• Nutritional support • Vitamin supplementation: vitamin E and water-soluble vitamins

Patient Care

• • • •

• Check liver enzymes and bilirubin every 7–14 days initially, then quarterly.

Prevention/ Avoidance

• High-fiber diet • Routine expression

• Control inflammatory bowel disease.

Complications

• Fecal incontinence following anal sacculectomy • Rupture • Septicemia

• • • • •

Prognosis

• Excellent • Guarded to poor with fecal incontinence

• Good with early treatment of suppurative disease • Variable with nonsuppurative

High fiber diet Exercise Express anal glands every 3–14 days until material is normal. Weight control

• Radiographs, abdominal: hepatomegaly and cholelithiasis • Ultrasonography: cholelithiasis, cholecystitis, obstruction, pancreatic abnormalities, and ↑ echogenecity of the liver

Antibiotics: ampicillin, amoxicillin cephalosporins, metronidazole Corticosteroids (NS): prednisolone Ursodeoxycholic acid: actigal Vitamin K1 therapy

Death Diabetes mellitus Hepatic lipidosis Pancreatitis and triad disease Recurrence of nonsuppurative forms

CHAPTER 6 / GENERAL MEDICINE

239

Table 6.21 / Gastroenterology: Anal Sac Disease, Cholangitis, and Cholangiohepatitis (Continued) Disease

Anal Sac Disease

Cholangitis and Cholangiohepatitis

Notes

• Color and consistency of anal gland contents: • Clear or pale yellow-brown: normal • Thick, pasty brown: impaction • Creamy yellow or thin green: infection • Yellow: inflammation • Red-brown exudate: abscessed

• Caution: Drugs used must be selected with care to not further damage the liver through metabolism. • Caution: Corticosteroids should not be used in suppurative forms. • Himalayan, Persian, and Siamese cats

6 Table 6.22 / Gastroenterology: Constipation and Megacolon Constipation and Megacolon

Definition

Constipation is a condition of prolonged fecal transit time, which contributes to increased water absorption leaving a hard, dry fecal mass. These fecal masses can cause irritation and inflammation of the intestinal mucosa and disrupt normal motility.

Treatment

Diagnosis

Presentation

Disease

240

Clinical Signs

• Anorexia, blood, depression, mucus, tenesmus, hard, dry feces, lack of fecal output, unkept haircoat, vomiting, weakness

Examination Findings

• Dehydration, distended and painful abdomen

General

• History/clinical signs • Abdominal palpation: enlarged colon with large fecal mass and a colon full of hypersegmented fecal balls • Digital rectal examination: fecal impaction and possible detection of underlying condition

Laboratory

• CBC: stress leukogram and ↑ PCV/TP • Chemistry panel: ↑ calcium, ↓ chloride and potassium • T4 (feline): ↑ values

Imaging

• Radiographs, abdominal: enlarged colon with large fecal mass, colon full of hypersegmented fecal balls, possible detection of underlying condition (e.g., pelvic fracture, spinal cord abnormalities) • Contrast, barium enema contrast • Ultrasound: obstructive tumors

Procedures

• Colonoscopy: obstructive mass or lesions

General

• • • •

Supportive Fluid therapy Manual evacuation of the colon Surgery: colostomy, colectomy, pelvic osteotomy

SECTION THREE: DIAGNOSTIC SKILLS

Table 6.22 / Gastroenterology: Constipation and Megacolon (Continued) Disease Medication

• Acetylcholinesterase inhibitors: ranitidine, nizatidine, neostigmine • Laxatives: • Bulk-forming: psyllium, pumpkin • Emollient: Colace, DSS • Lubricant: mineral oil, Laxatone, or sterile lubricant jelly • Osmotic: lactulose, milk, or glycerin • Misoprostol • Prokinetic agents: cisapride

Nursing Care

• Encourage to defecate: clean litter pan, multiple walks

Patient Care

• Encourage activity and exercise after postoperative recovery. • Dietary fiber supplements: psyllium, wheat bran, pumpkin • ↑ Exercise

Treatment Follow-Up

Constipation and Megacolon

Prevention/ Avoidance

• Same as above

Complications

• • • •

Prognosis

• Fair with lifelong treatment • Poor with megacolon

Notes

6

Megacolon Obstipation Perforation of colon wall during manual evacuation Peritonitis, diarrhea, or stricture formation post surgery

• Typically seen in the transverse and descending colon • Verify adequate hydration before adding dietary fiber supplements

Table 6.23 / Gastroenterology: Diarrhea Disease

Diarrhea Acute

Presentation

Definition

Chronic

Diarrhea can be acute or chronic (lasting longer than 3–4 weeks) and either small bowel or large bowel. The causes range from dietary indiscretion, toxins, drugs, intestinal parasites, infectious diseases, and systemic or metabolic disturbances.

Clinical Signs

• • • •

Anorexia, lethargy, vomiting Clinical signs of an underlying condition Small bowel diarrhea: watery, voluminous, and fetid Large bowel diarrhea: watery, mucoid, bloody feces with tenesmus and ↑ sense of urgency

Examination Findings

• Abdominal pain, dehydration, ileus, pyrexia

CHAPTER 6 / GENERAL MEDICINE

241

Table 6.23 / Gastroenterology: Diarrhea (Continued) Disease

Diarrhea Acute

General

• History/clinical signs • Abdominal palpation: mass lesions, pain, mesenteric lymphadenopathy, thickened or fluid-distended bowel loops • Digital rectal palpation: masses, strictures, or anal diseases

Laboratory

• • • • • •

Fecal flotation: parasites or bacteria Fecal direct smear: cysts, larvae, and trophozoites Cytology, fecal: bacteria, fungi, protozoan, inflammatory cells Culture, fecal: + T. foetus (feline) ELISA: parvovirus, Giardia, rotavirus Folate and cobalamin: dependent on different conditions and locations of problems • IFA Giardia/Crypotospordium: +

• • • •

Imaging

• Radiographs, abdominal: foreign bodies, obstruction, intussusception, and ileus

• Radiographs, abdominal: obstruction, mass, foreign body, organomegaly • Contrast study: bowel wall thickening or irregularity, tumor, stricture or foreign body • Ultrasonography: bowel wall thickening or irregularity, mass, foreign body, intussusception, ileus, or other disease process

Procedures

• ± Endoscopy: obtain biopsies

• Endoscopy: obtain biopsies

General

• Supportive • Fluid therapy • Surgery: laparotomy to remove obstruction

• Supportive • Fluid therapy • Surgery: laparotomy to remove obstruction or mass or obtain full thickness biopsy

Medication

• • • • •

• Anthelmintics: fenbendazole and metronidazole

Nursing Care

• NPO for at least 24 hours • Provide a clean litter box or frequent walks.

• Provide a clean litter box or frequent walks.

Patient Care

• Recheck fecal analysis following treatment for parasites. • Small, frequent meals • Bland or hypoallergenic diet

• Bland or hypoallergenic diet • Monitor fecal output: consistency, frequency • Monitor body weight

Prevention/ Avoidance

• Yearly fecal analysis

• Yearly fecal analysis

Diagnosis Treatment Follow-Up

6

242

Chronic

Antibiotics Anthelmintics: fendendazole and metronidazole Local protectant: bismuth subsalicylate Motility modifiers: opiates, loperamide, diphenoxylate Probiotics

SECTION THREE: DIAGNOSTIC SKILLS

CBC: eosinophilia, macrocytosis, and anemia Fecal flotation: parasites or bacteria Fecal cytology: infectious agents or inflammatory cells Folate and cobalamin: ↓↑ depending on different conditions

Table 6.23 / Gastroenterology: Diarrhea (Continued)

Follow-Up

Disease

Diarrhea Acute

Chronic

Complications

• Intussusception

• Dehydration • Abdominal effusion with intestinal adenocarcinoma • Inflammatory bowel disease

Prognosis

• Excellent in mild cases and with proper treatment of severe cases • Poor with chronic diarrhea unresponsive to treatment

Notes

• Most acute diarrhea is self-limiting within 3–4 days. • Do not administer bismuth subsalicylate to cats.

6 Table 6.24 / Gastroenterology: Exocrine Pancreatic Insufficiency and Gastric Dilatation-Volvulus Exocrine Pancreatic Insufficiency (EPI)

Gastric Dilatation-Volulusa (GDV, gastric torsion, bloat)

Definition

EPI is the insufficient secretion of digestive enzymes and clinical signs of malabsorption. It occurs with severe progressive loss of acinar tissue from atrophy and is most commonly seen in middle-aged to older dogs.

GDV is the process in which the stomach becomes dilated with gas or fluid and rotates on its central axis. Gastric dilatation can also occur without torsion, but surgery is still indicated as there is an 80% recurrence rate.

Clinical Signs

• Cachexia, coprophagia, diarrhea, dull haircoat, excessive shedding, feces voluminous, flatulence, greasy oily hair around perineum, ↓ muscle mass, pica, ravenous appetite, unthrifty, vomiting, ↑ water intake

• Abdominal distention, belching, collapse, depression, dry heaving (failed attempts to vomit), excessive salivation, respiratory distress, weakness

Examination Findings

• Borborygmus, dehydration

• ↑ Capillary refill time, cool extremities, ↓ femoral pulses, pale mucous membrane, tachycardia, tachypnea, tympanic cranial abdomen

General

• History/clinical signs

• History/clinical signs

Laboratory

• CBC: mild lymphophenia and eosinophilia • Chemistry panel: ↑ ALT and ↓ cholesterol, lipids, polyunsaturated fatty acids • TLI assay: <5 μg/dL (dogs) and <31 μg/dL (feline) • TLI stimulation test: no response • Fecal elastase: <10 μg/gm • Fecal proteolytic activity: ↓ values • Oral bentiromide digestion test: minimal ↑ PABA • Folate: variable depending on different conditions • Cobalamin: ↓ value

• • • • • •

Imaging

• N/A

• Radiographs, abdominal: “double-bubble” with air-filled pylorus

Procedures

• N/A

• Abdominocentesis/cytology: gastric perforation and peritonitis

Diagnosis

Presentation

Disease

CBC: variable PCV/TP Chemistry panel: ↓ potassium Urinalysis: ↑ specific gravity Blood gas analysis: metabolic acidosis Coagulation tests, PT, APTT, FDP: ↑ time Plasma lactate: <6 mmol/L ↑ survival rate

CHAPTER 6 / GENERAL MEDICINE

243

Table 6.24 / Gastroenterology: Exocrine Pancreatic Insufficiency and Gastric Dilatation-Volvulus (Continued) Exocrine Pancreatic Insufficiency (EPI)

Gastric Dilatation-Volulusa (GDV, gastric torsion, bloat)

General

• Symptomatic

• • • • • •

Symptomatic Supportive Fluid therapy Oxygen therapy Decompression with orogastric tube/trocarization/gastric lavage Surgery: exploratory celiotomy with gastropexy

Medication

• • • •

• • • • • •

Alkalinizer: sodium bicarbonate Antiarrthymics: lidocaine, procainamide Antibiotics: cefazolin, cefoxitin, enrofloxacin, metronidazole Anticoagulant: heparin Corticosteroids: dexamethasone phosphate H2-receptor: famotidine, ranitidine

Nursing Care

• Divide daily food intake into 2–3 meals. • Diet should be low in fiber and highly digestible. • Multivitamin, especially fat-soluble vitamins, cobalamin, and tocopherol

• • • •

NPO for 12–24 hours following surgery Fluid therapy Oxygen therapy Monitor: acid-base status, BP, CBC, chemistry panel, CVP, ECG, electrolytes, urine output

Patient Care

• Monitor weight gain and fecal consistency. • Gradually ↓ enzyme replacement as animal returns to normal.

• Gradually return to normal diet.

Prevention/ Avoidance

• N/A

• Feed smaller meals multiple times a day. • Avoid postprandial exercise.

Complications

• Small bowel bacterial overgrowth • Inadequate response to pancreatic enzyme replacement • Small intestine disease

• • • • •

Prognosis

• Good with dietary and enzyme management • Poor when associated with diabetes mellitus

• Guarded to grave • Good, patients recovering 7 days post treatment

• German Shepard, Rough-coated Collie • Cobalamin must be given SQ for absorption

• Large, deep-chested breeds: Irish Setter, Great Dane, Saint Bernard, Rottweiler, Alaskan Malamute, Labrador Retriever, German Shepards (any breed possible)

Treatment

Disease

Follow-Up

6

Notes

a

Antibiotics: tetracyclines, metronidazole, tylosin H2-receptor blocker: cimetidine and ranitidine Pancreatic enzyme replacement added to each meal Vitamin supplements: cobalamin, vitamins E, K1

See Emergency Medicine, Chapter 7, page 314, and Surgery, Chapter 15, page 521.

244

SECTION THREE: DIAGNOSTIC SKILLS

Arrythmias Aspiration pneumonia DIC Gastric ulceration and peritonitis Reperfusion illness/toxicosis

Table 6.25 / Gastroenterology: Hepatic Disease/Failure Hepatic Disease/Failure (Liver Disease)

Definition

“Hepatic failure” results from the sudden loss of >75% of functioning hepatic mass, and “hepatic disease” is the accumulation of inflammatory cells in the liver over an extended period of time with adequate liver function. Causes include infectious agents, drugs, toxins, immunemediated, traumatic injury, thermal injury, and hypoxia.

Clinical Signs

• Anorexia, circling, constipation, dementia, depression, diarrhea, disorientation, hematuria, hypersalivation, lethargy, melena, nausea, PU/PD, seizures, vomiting

Examination Findings

• Abdominal pain, ascites, ataxia, dementia, hemorrhages, hepatomegaly, pyrexia, jaundice, microhepatica, pallor

General

• History/clinical signs • Abdominal palpation: hepatomegaly and hepatodynia

Laboratory

• CBC: normocytic, normochromic nonregenerative anemia, thrombocytopenia and ± nucleated RBCs • Chemistry panel: ↑ ALT, AST, ALP, GGT, total bilirubin, globulin, ammonia, BUN (acute), glucose (chronic), cholesterol and ↓ albumin, BUN (chronic), glucose (acute), and cholesterol • Urinalysis: ↑ bilirubin, urobilinogen, ammonia, bilirubin crystals, ammonium biurate crystals, and ↓ specific gravity • Coagulation profile, ACT, PTT, PT: prolonged • Bile acid concentrations: ↑ values • Fasting bile acid concentrations: >30 μmol/L • Postprandial bile acid concentrations: >30 μmol/L • Blood ammonia concentrations: ↑ values • Ammonia tolerance test: ↑ values

Imaging

• Radiographs, thoracic: metastasis to lung parenchyma • Radiographs, abdominal: ↑ or ↓ in liver size, changes in tissue characteristics and contours • Ultrasonography: masses, abscesses, cysts, obstructions, and lesions

Procedures

• Biopsy: to determine the nature and severity of hepatic disease

General

• • • •

Symptomatic Supportive Fluid therapy Paracentesis with respiratory distress

Medication

• • • • • • • • • • • •

Antibiotics: penicillin, ampicillin, cephalosporins, metronidazole, and aminoglycosides Antioxidants: vitamins E, C, S-adenosyl-L-methionine, milk thistle Azathioprine (use cautiously) Cholchicine Corticosteroids: prednisolone GI protectants: sulcralfate H2-blocker: ranitidine and cimetidine Lactulose Phenobarbital Ursodeoxycholic acid: actigal Vitamin K therapy Zinc

Treatment

Diagnosis

Presentation

Disease

CHAPTER 6 / GENERAL MEDICINE

6

245

Table 6.25 / Gastroenterology: Hepatic Disease/Failure (Continued) Hepatic Disease/Failure (Liver Disease)

Nursing Care

• • • • •

Patient Care

• Monitor CBC and serum biochemistry frequently depending on severity of presenting condition. • Follow–up biopsies at 6 and 12 months • Dietary modifications (e.g., ↓ copper)

Prevention/ Avoidance

• Vaccinate against infectious agents. • Screen susceptible breeds. • Avoid hepatotoxic drugs.

Complications

• • • • • •

Prognosis

• Dependent on the amount of viable liver mass left after treatment • ↑ Prognosis with determination of underlying cause

Notes

Moderate activity restriction Nutritional support Monitor body weight, temperature, pulse, respiration, and mental status. Vigilant monitoring for signs of infection Vitamin and mineral supplements

Death DIC and bleeding diatheses GI ulceration Liver failure and liver encephalopathy Renal disease or failure Sepsis

• Caution: Drugs used must be selected with care to not further damage the liver through metabolism • Caution: Avoid alkalinizing agents (e.g., lactate, sodium bicarbonate) with patients with hepatic encephalopathy • Bedlington Terrier, Doberman Pinscher, Cocker Spaniel, Labrador Retriever, Standard Poodle, Skye Terriers, and West Highland White Terrier

Table 6.26 / Gastroenterology: Hepatic Lipidosis and Inflammatory Bowel Disease Disease

Hepatic Lipidosis (Fatty Liver Disease)

Inflammatory Bowel Disease (IBD)

Definition

Hepatic lipidosis is seen almost exclusively in cats. It is the result of >50% of cells in the liver accumulating excessive trigylcerides. This disease will lead to death if left untreated. This occurs when there is difference in the rates of deposition and metabolism of fat. It often occurs with prolonged anorexia.

IBD is a group of gastrointestinal diseases that infiltrate the mucosa and submucosa with inflammatory cells. It may involve the stomach, small and large intestines, or a combination. Lymphocyticplasmacytic is the most common type of IBD, found in both dogs and cats.

Clinical Signs

• Constipation, depression, diarrhea, lethargy, prolonged anorexia, vomiting, weakness, weight loss

• Diarrhea, flatulence, hematochezia, intermittent vomiting, listless, mucus, poor haircoat, steatorrhea, tenesmus, vomiting, weight loss

Examination Findings

• Dehydration, hepatomegaly, jaundice, muscle wasting, pallor

• Mesenteric lymphadenopathy, thickened bowel loops

Presentation

6

Follow-Up

Treatment

Disease

246

SECTION THREE: DIAGNOSTIC SKILLS

Table 6.26 / Gastroenterology: Hepatic Lipidosis and Inflammatory Bowel Disease (Continued) Hepatic Lipidosis (Fatty Liver Disease)

Inflammatory Bowel Disease (IBD)

General

• History/clinical signs: obesity

• Clinical signs • Canine IBD Analysis Index (CIBDAI)

Laboratory

• CBC: normocytic, normochromic nonregenerative anemia with poikilocytosis (if prolonged) and neutrohilia and lymphopenia (v) • Chemistry panel: ↑ ALP, ALT, AST, GGT, ammonia, bilirubin, ↓ potassium, phosphorous, albumin, BUN, and azotemia (v) • Urinalysis: ↑ lipids and bilirubin • Coagulation profile, ACT, PTT, PT: prolonged • Bile acid concentrations: ↑ values

• CBC: mild, nonregenerative anemia or mild leukocytosis without a left shift (feline) and neutrophilic leukocytosis with a left shift (canine) • Chemistry panel: ↑ T4 (feline), ↓ protein (canine), and albumin (feline) • Fasting serum TLI: to rule out EPI • Cobalamin and folate assays: ↓↑ depending on different conditions • FeLV/FIV: + results

Imaging

• Radiographs, abdominal: hepatomegaly • Ultrasonography: hepatomegaly and hyperechoic liver

• Radiographs, abdominal: survey films to rule out other diseases • Barium contrast study: mucosal abnormalities and thickened bowel loops • Ultrasonography: measure stomach and intestinal wall thickness and rule out other diseases

Procedures

• Biopsy: hepatocellular vacuoles

• Endoscopy: intestinal biopsies

General

• Supportive • Fluid therapy

• Symptomatic • Fluid therapy if vomiting • Surgery: entertomy biopsies

Medication

• • • • •

• 5-Aminosalicyclic drugs: sulfasalazine, olsalazine, and mesalamine • Antibiotics: metronidazole, oxytetracycline, tylosin • Antidiarrheal drugs: loperamide, diphenoxylate • Corticosteroids: prednisone, budesonide • Chemotherapy: chlorambucil • Cyclosporin A • Immunsuppression: azathioprine • Probiotics

Nursing Care

• Aggressive nutritional support via syringe, nasogastric tube, esophagostomy tube or gastrotomy tube • Vitamin supplementation: vitamin B12, vitamin E, thiamine, taurine, arginine, L-carnitine, and L-citrulline

• Nutritional support if severely malnourished • Vitamin supplementation: folic acid, cobalamin, omega-3, vitamin B12, fat-soluble vitamins

Patient Care

• Continuous feeding via tube by owners for 4–6 weeks or for 10 days post vomiting, eating on their own and normal biochemical values • Monitor potassium and phosphorus • Monitor body weight and hydration

• Hypoallergenic dietary management • Periodic evaluations until patient stabilizes

Prevention/ Avoidance

• Prevent anorexia (especially obese felines) • Monitor food intake in obese cats during times of stress or other disease processes

• N/A

Follow-Up

Treatment

Diagnosis

Disease

Antiemetic: metoclopramide Antibiotics: ampicillin, amoxicillin, metronidazole Lactulose Ursodeoxycholic acid: actigal Vitamin K therapy

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6

Table 6.26 / Gastroenterology: Hepatic Lipidosis and Inflammatory Bowel Disease (Continued)

Follow-Up

Disease

Hepatic Lipidosis (Fatty Liver Disease)

Inflammatory Bowel Disease (IBD)

Complications

• • • •

• • • • •

Prognosis

• Grave if left untreated • 65% of patients recover with proper treatment

• Good with continuous maintenance of remission and control of relapses • Course of disease tends to be progressive in prone breeds.

• Caution: Avoid dextrose supplementation as it interferes with fat oxidation. • Majority of felines are obese before this disease process starts. • Vitamin K should be given IM at least 12 hours before biopsies. • Biopsy samples typically float when placed in formalin.

• A hypoallergenic protein source refers to one to which the patient has not yet been exposed or a hydrolyzed diet. • The diet should also be void of artificial colorings, flavors, and preservatives. • Feed a novel protein source for 6 weeks while the GIT heals; then switch to another novel protein source. • Basenji, Soft-Coated Wheaton Terrier, and Shar pei

Notes

6

Vomiting Tube dysfunction Hepatic failure Death

Adverse drug reactions Anemia Malnutrition and dehydration Protein losing enteropathy Small intestinal bacterial overgrowth

Table 6.27 / Gastroenterology: Megaesophagus Megaesophagus (Esophageal Hypomotility)

Definition

Megaesophagus is a segmental or diffuse hypomotility and dilation of the esophagus. There are three main causes: congenital, acquired idiopathic or secondary to another condition (e.g., myasthenia gravis, brain stem lesion, tetanus)

Diagnosis

Presentation

Disease

248

Clinical Signs

• Cough, dyspnea, emaciation, generalized muscle weakness or atrophy, halitosis, mucopurulent nasal discharge, regurgitation, salivation, weight loss

Examination Findings

• Pyrexia, neurologic deficits, pulmonary crackles, raspy breath sounds

General

• History/clinical signs • Palpation of dilated esophagus

Laboratory

• CBC: neutrophilia and left shift • Acetycholine receptor antibody titer: screen for myasthenia gravis

Imaging

• Radiographs, thoracic: distention of esophagus with air, fluid or food, aspiration pneumonia • Contrast study: ↓ movement and pooling of fluid

Procedures

• Fluoroscopy: ↓ strength and coordination or peristaltic contractions • Endoscopy: dilated esophagus, foreign body, neoplasia, and esophagitis

SECTION THREE: DIAGNOSTIC SKILLS

Table 6.27 / Gastroenterology: Megaesophagus (Continued)

Follow-Up

Treatment

Disease

Megaesophagus (Esophageal Hypomotility)

General

• Symptomatic • Supportive

Medication

• • • •

Nursing Care

• Nutritional support to ensure passage of food past dilated esophagus • ↑ Caloric density diet

Patient Care

• Offer small, frequent meals with patient in upright position for 10–15 minutes following meal.

Prevention/ Avoidance

• Diligent feeding rituals will increase life span. • Early detection of recurrent pneumonias

Complications

• Weight loss • Aspiration pneumonia

Prognosis

• Fair with diligent supportive care

Notes

Antibiotics for aspiration pneumonia: variable H2-blockers: sulcralfate Metoclopramide Prokinetic agents: cisapride

6

• Feeding small “meatballs” of canned food to a patient in an upright position often ↓ regurgitation.

Table 6.28 / Gastroenterology: Pancreatitis and Peritonitis Pancreatitis

Peritonitis

Definition

Pancreatitis is inflammation of the pancreas that can be either acute or chronic. Chronic pancreatitis is often seen with morphological changes in the pancreas. It can be caused by obesity, ingestion of excessive fat, or multiple other disease processes.

Peritonitis is a life-threatening condition that requires progressive medical management for resolution. Peritonitis is an inflammatory process involving all or part of the peritoneal cavity.

Clinical Signs

• Anorexia, depression, diarrhea, jaundice, panting, praying position, restlessness, tachypnea, trembling, vomiting, weakness

• Diarrhea, praying posture, reluctance to move, tachypnea, tucked up abdomen, vomiting

Examination Findings

• Dehydration, pyrexia, cranial abdominal pain, and mass effect

• Abdominal pain, dehydration, pyrexia, shock, tachycardia

Presentation

Disease

CHAPTER 6 / GENERAL MEDICINE

249

Table 6.28 / Gastroenterology: Pancreatitis and Peritonitis (Continued)

Diagnosis

Disease

Pancreatitis

Peritonitis

General

• History/clinical signs • Abdominal palpation: enlarged and painful pancreas

• History/clinical signs • Abdominal palpation: pain or organomegaly

Laboratory

• CBC: neutrophilia with or without a left shift, leukocytosis, thrombocytopenia, anemia • Chemistry panel: ↑ amylase, lipase, ALP, ALT, bilirubin, BUN, creatinine, cholesterol, lipids, glucose, ↓ albumin, calcium (v) and azotemia (acute type) • Canine pancreatic lipase immunoreactivity (cPLI): ↑ value • Feline pancreatic lipase immunoreactivity (fPLI): ↑ value • TLI: ↑ value

• CBC: neutrophilia with or without a left shift, leukocytosis, and anemia • Chemistry panel: ↑ amylase, lipase, ALT, AST, bilirubin, ↓ protein, glucose, potassium, electrolyte imbalances, and azotemia • Cytology, abdominal: degenerate neutrophils and intracellular bacteria • ± Culture: bacteria isolation and identification

Imaging

• Radiographs, thoracic: pulmonary edema or pleural effusion (rare) • Radiographs, abdominal: displacement of stomach and duodenum,↑ density, ↓ contrast gastric distention, static gas pattern, thickened and corrugated walls of the duodenum • Ultrasonography: irregular enlargement and abscesses of the pancreas, hyper- and hypoechoic changes, peripancreatic fluid accumulation • Contrast CT: identification and management

• Radiographs, abdominal: free fluid or air, ↓ detail, ileus, distention of loops of bowel with fluid or gas • Iodinated contrast studies: GIT to locate perforation • Ultrasonography: free fluid, abscesses, masses and cause of peritonitis

Procedures

• Biopsy: confirmed diagnosis

• Abdominocentesis

General

• • • •

• • • •

Medication

• Analgesics: meperidine HCl and butorphanol • Antibiotics: ampicillin, cephalosporins, trimethoprim-sulfa, and enrofloxacin • Antiemetics: chlorpromazine, dolasetron, ondansentron • Corticosteroids (shock): prednisone • Glucagon • Somatostatin • Vasopression

• Analgesics: variable • Antibiotics: penicillin, cephalosporins or aminoglycosides, ampicillin, enrofloxacin

Nursing Care

• NPO • Potassium supplementation • Complete rest and confinement

• Standard postoperative • Limit activity. • Nutritional support

Patient Care

• After vomiting has stopped for 1–2 days, slowly reintroduce water followed by a gradual reintroduction of a high-carbohydrate diet.

• Check CBC, chemistry profile, and urinalysis every 1–2 days, even in patients who are responding.

Prevention/ Avoidance

• Avoid fatty foods and dietary indiscretion. • Maintain optimum weight control. • Avoid corticosteroid treatment.

• N/A

Follow-Up

Treatment

6

250

Symptomatic Supportive Fluid therapy Surgery: laparotomy

SECTION THREE: DIAGNOSTIC SKILLS

Supportive Fluid therapy Peritoneal lavage Surgery: laparotomy, correct primary etiology, lavage and drain placement

Table 6.28 / Gastroenterology: Pancreatitis and Peritonitis (Continued) Disease

Pancreatitis ↓ Protein and oncotic pressure Peritonitis Renal failure, acute Septic shock Thromboembolic disease Worsening pancreatitis

Peritonitis • Herniation of abdominal contents • Adhesions

• • • • • •

Prognosis

• Fatal without treatment • Poor with complications

• Poor even with adequate treatment

• Patients with recurrent pancreatitis may try a trial period of enzyme therapy.

• Caution: Do not use povidone-iodine solution for lavage as it may be absorbed and produce toxic effects. • Use a contrast medium with minimal abdominal effects in case of leakage (e.g., iohexol).

Follow-Up

Complications

Notes

Table 6.29 / Gastroenterology: Protein-Losing Enteropathy and Vomiting Protein-Losing Enteropathy

Vomiting

Definition

Protein-losing enteropathy is a disease of excessive loss of serum protein into the intestinal tract. It can be a primary GIT disease or the result of a generalized condition such as congestive heart failure, nephrotic syndrome, or metastatic neoplasia.

Vomiting is the forceful, reflex expulsion of gastric or proximal small bowel contents from the oral cavity. Its duration can be acute or chronic (>14 days).

Clinical Signs

• Diarrhea, dyspnea

• Anorexia, depression, hypersalivation, nausea, repeated swallowing, and licking of lips • Others depending of underlying disease

Examination Findings

• Ascites, edema, pleural effusion, thickened bowel loops

• Abdominal distention or pain

General

• History/clinical signs • Abdominal palpation: intestines

• History/clinical signs • Examination of vomitus

Laboratory

• • • • • • • •

Diagnosis

Presentation

Disease

CBC: +/− anemia and +/− lymphopenia Chemistry panel: ↓ albumin, globulin, calcium, and cholesterol Urinalysis: ↑ protein-to-creatinine ratio Fecal examinations: rule out parasites and bacterial overgrowth TLI and folate: results dependent on disease process Cobalamin: ↓ values Serum bile acids: assess hepatic function T4: ↑ values (feline)

• Dependent on underlying condition

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6

Table 6.29 / Gastroenterology: Protein-Losing Enteropathy and Vomiting (Continued) Protein-Losing Enteropathy

Vomiting

Imaging

• Radiographs, thoracic: rule out cardiac disease or fungal disease • Radiographs, abdominal: rule out fungal disease, tumors or intestinal obstruction • Contrast: tumor or bowel disease • Ultrasound: abdominal abnormalities or tumors

• • • •

Procedures

• Endoscopy: mucosal visualization and biopsy

• Endoscopy: stomach and proximal duodenum abnormalities

General

• • • •

Symptomatic Supportive Blood or hetastarch transfusions Surgery: laparotomy for diagnostic full-thickness biopsies

• Symptomatic • Fluid therapy • Surgery: exploratory laparotomy

Medication

• • • • •

Antibiotics: metronidazole, tylosin, or sulfasalazine Chemotherapy: chlorambucil Corticosteroids: prednisone Diuretics: furosemide Immunosuppressive: azathioprine, cyclosporin

• Antiemetic: metoclopramide, diphenhydramine, prochlorperazine, and chlorpromazine • Antisecretory: cimetidine, famotidine, rantidine, omeprazole • GI protectants: sulcralfate

Nursing Care

• Treated as outpatient • Standard postoperative

• NPO

Patient Care

• Dietary modifications depending on underlying cause • Recheck body weight and protein concentrations every 7–14 days. • Monitor for reoccurrence of clinical signs.

• After vomiting has stopped for 12 hours, slowly reintroduce water followed by a gradual reintroduction of a single protein and carbohydrate diet. • Wean back to regular diet over 4–5 days.

Prevention/ Avoidance

• Control inflammatory bowel disease

• Avoid dietary indiscretion

Complications

• • • •

• Dehydration • Electrolyte imbalances • Aspiration pneumonia

Prognosis

• Guarded

• Excellent in mild cases and with proper treatment of severe cases

• ↑ Risk of morbidity postoperative due to slow wound healing because of ↓ albumin, serosal patch graft may be necessary

Types of vomiting • Undigested or partially digested food >12–16 hours old: delayed gastric emptying • Projectile vomiting: gastric or upper small bowel obstruction • Praying mantis position: gastrointestinal pain Physical appearance of vomit • Bile: gastroduodenal reflux • Fresh blood: recent bleeding in esophagus or stomach • Digested blood: ulcer disease • Mucus: concurrent irritation of stomach and intestines

Follow-Up

6

Treatment

Diagnosis

Disease

Notes

252

Diarrhea, severe Malnutrition, severe Respiratory difficulty Slow wound healing

SECTION THREE: DIAGNOSTIC SKILLS

Radiographs, thoracic: heartworm disease Radiographs, abdominal: foreign body, pancreatitis, or pyometra Contrast: foreign body Ultrasound: abdominal abnormalities or tumors

HEMATOLOGY Table 6.30 / Hematology: Anemia and Disseminated Intravascular Coagulation Disease

Anemia Nonregenerative

Disseminated intravascular coagulation is a complex condition that is always secondary to another disease process. It is defined as an excessive activation of the clotting mechanism with complete consumption of clotting factors.

Clinical Signs

• Anorexia, collapse, depression, dyspnea, exercise intolerance, melena, tachypnea, weakness

• Clinical signs of underlying disease • Dyspnea, melena, petechiae, spontaneous hemorrhage from orifices

Examination Findings

• Flea infestation, icteric, lymphadenopathy, pallor, petechiae, pyrexia, retinal hemorrhages, soft systolic murmur, splenomegaly, tachycardia

• Pyrexia, subcutaneous hematoma and petechiae, tachycardia

General

• History/clinical signs

• History/clinical signs

Laboratory

• CBC: ↑ MCV, ↓ PCV, MCHC, TP, leukopenia, thrombocytopenia • Urinalysis: ↑ blood, +/− bilirubin • Fecal analysis: hookworms and coccidia • ELISA: FeLV in-house screening • Cytology, bone marrow: erythroid hypoplasia

• CBC: ↑ +/− MCHC, ↓ PCV, +/− MCV, TP, reticulocytosis, neutrophilia, thrombocytosis, nucleated RBCs, basophilic stippling (feline), spherocytes (canine, IMHA) • Chemistry panel: ↑ bilirubin • Fecal analysis: hookworms and coccidian • Corrected reticuloctye %: >1% • Cytology, bone marrow: erythroid hyperplasia • COOMBS test and ANA serology: + results • Slide agglutination test: + results indicate anemia is immune-mediated

• CBC: thrombocytopenia, schistocytes, ↓ platelet count, fibrinogen levels, and presence of fibrin degradation products • Chemistry panel: ↑ BUN • Urinalysis: hematuria • FDP assay: + • Coagulation tests, PT, PTT, ACT: ↑ times • Latex agglutination test: ↑ value

Imaging

• Radiographs, abdominal: splenomegaly

• Radiographs, thoracic: fluid • Radiographs, abdominal: fluid

• N/A

Procedures Treatment

Regenerative

Anemia is a decreased number of necessary RBC and is a primary bone marrow dysfunction. It can be caused by RBC loss, destruction, or depression of production. Anemia is typically broken down in two types: regenerative (loss and destruction) and nonregenerative (depression of production). Regenerative anemia can be immune-mediated, causing the destruction of RBCs and ending in immune-mediated hemolytic anemia (IMHA).

Diagnosis

Presentation

Definition

Disseminated Intravascular Coagulation (DIC)

General

• N/A • • • •

Supportive Blood transfusions Fluid therapy Oxygen therapy

• • • •

Symptomatic Aggressive fluid therapy Blood transfusions Oxygen therapy

CHAPTER 6 / GENERAL MEDICINE

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6

Table 6.30 / Hematology: Anemia and Disseminated Intravascular Coagulation (Continued)

Treatment

Disease

Disseminated Intravascular Coagulation (DIC)

Nonregenerative

Regenerative

Medication

• Immunosuppression: cyclosporine • Erythropoietin • Ferrous sulfate

• Antibiotics: tetracyclines • Corticosteroids: prednisone, dexamethasone • Immunosuppression: azathioprine, cyclophosphamide, danazol, chlorambucil • Ferrous sulfate

Nursing Care

• • • • •

Patient Care

• Monitor CBC every 3–5 days until normal. • Monitor blood pressure.

• Monitor PCV weekly until normal, then every 2 weeks for 2 months, then monthly. • Monitor CBC monthly during treatment.

• Related to underlying disease

Prevention/ Avoidance

• Neuter cryptorchid males. • Monitor CBCs of patients receiving cancer drugs.

• N/A

• Related to underlying disease

Complications

• • • •

• • • • •

• Related to underlying disease

Prognosis

• Guarded to poor unless underlying disease can be diagnosed and treated • Recovery make take weeks to months.

6

Follow-Up

Anemia

Monitor for adverse reactions to drugs and transfusions. Monitor heart rate, respiratory rate, and temperature. Heat support Restrict activity Nutritional support

Blood transfusion related Erythropoietin related Hemorrhage Sepsis

Notes

Cardiac arrhythmias DIC Embolisms Hypoxia Infections

• • • • • •

Antibiotics Anticoagulant: sodium heparin Corticosteroids (endotoxic shock) Cryoprecipitate Diuretics: mannitol NSAIDs: aspirin

• • • •

Avoid IM injections and neck leads. Strict confinement Feed soft foods. Use peripheral blood vessels from blood draws and catheter placement.

• Poor to good prognosis with appropriate treatment • Guarded to poor prognosis with IMHA

• Grave

• IMHA: Old English Sheepdog, Cocker Spaniel, Poodle, Irish Setter, English Springer Spaniel, and Collie

• Caution: Venipuncture sites can lead to excessive hematomas; place pressure wraps following procedure.

Table 6.31 / Hematology: Thrombocytopenia and von Willebrand’s Disease Disease

Thrombocytopenia, Immune-Mediated (IMT, Idiopathic Thrombocytopenic Purpura, ITP, Autoimmune Thrombocytopenia)

von Willebrand Disease

Definition

Thrombocytopenia is a deficiency of platelets. Primary immunemediated is the destruction of platelets with no identifiable cause. It may occur as a single entity or as a combination of other immune-mediated diseases.

von Willebrand disease is a bleeding disorder caused by a deficiency or dysfunction of the plasma protein (von Willebrand’s factor, vWF) used for normal platelet functions. This is the most common inherited bleeding disorder in dogs.

254

SECTION THREE: DIAGNOSTIC SKILLS

Table 6.31 / Hematology: Thrombocytopenia and von Willebrand’s Disease (Continued) Thrombocytopenia, Immune-Mediated (IMT, Idiopathic Thrombocytopenic Purpura, ITP, Autoimmune Thrombocytopenia)

von Willebrand’s Disease

Clinical Signs

• Anorexia, dyspnea, retinal and mucosal hemorrhages, epistaxis, hematochezia, melena, lethargy, vomiting, weakness

• ↑ Hemorrhage from wounds and surgery sites, spontaneous hemorrhage from mucosal surfaces of oral and nasal cavities, GIT, and genitourinary tract

Examination Findings

• Murmur, pallor, pyrexia, tachycardia

• Internal hemorrhage

General

• History/clinical signs • Patient response to treatment

• History/clinical signs

Laboratory

• CBC: thrombocytopenia <50,000/μL, microthrombocytosis, neutrophilia or neutropenia, schistocytes, autoagglutination, anemia • Chemistry panel: mild ↑ ALT and ALP (v) and ↓ protein • Urinalysis: ↑ Protein and blood (rare) • Platelet count: thrombocytopenia, ↑ shift platelets, immature platelets • Cytology: bone marrow: ↑ megakaryocytes • Serology: erlichiosis, Rocky Mountain spotted fever, dirofilariasis and leptospirosis • ANA titer: + results • Coagulation profiles: ↓ clotting times

• CBC: anemia, neutrophilia and a mild left shift and reticulocytosis after acute bleeding, thrombocytopenia, megathrombocytosis • Chemistry panel: ↑ ALT, AST • Buccal mucosa bleeding time: ↑ time • Toenail bleeding time: ↑ time • vWF antigen assay: ↓ values • Platelet function analyzer: ↑ time • Collagen binding assay • DNA testing: classifies affected and carriers

• Radiographs, thoracic: tumors • Radiographs, abdominal: tumors

• N/A

Diagnosis

Presentation

Disease

Imaging

Treatment

Procedures

• N/A

General

• • • •

Supportive Fluid therapy Blood transfusion Surgery: splenectomy

• • • •

Supportive Fluid therapy Hormonal therapy Blood transfusions

Medication

• Corticosteroids: prednisone, prednisolone, dexamethasone • Immunosuppressant: vincristine, cyclophosphamide, azathioprine, danazol, cyclosporine, leflunomide • H2-blockers: sulcralfate • Human immunoglobulin

• Cryoprecipitate: a concentrated form of vWF and factor VIII • Desmopressin acetate: ↑ vWF and ↓ bleeding time

Nursing Care

• Treated as outpatient • Standard postoperative • Strict confinement

• • • •

Avoid IM injections, neck leads, trauma, etc. Strict confinement Feed soft foods Use peripheral blood vessels from blood draws and catheter placement

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6

Table 6.31 / Hematology: Thrombocytopenia and von Willebrand’s Disease (Continued)

Follow-Up

Disease

6

Thrombocytopenia, Immune-Mediated (IMT, Idiopathic Thrombocytopenic Purpura, ITP, Autoimmune Thrombocytopenia)

von Willebrand’s Disease

Patient Care

• Strict confinement until normal platelet counts return • Monitor platelet counts periodically following recovery.

• Monitor for hemorrhages for 48 hours post surgery.

Prevention/ Avoidance

• • • •

• Neuter affected dogs. • Selective breeding based on DNA testing

Complications

• GI ulceration • CNS hemorrhage • Hemorrhagic shock

• Hemorrhage

Prognosis

• Good with corticosteroid treatment

• Depends on the concentration of the von Willebrand’s factor

Avoid unnecessary vaccinations. Minimize stress. Avoid medications that are suspected of having caused initial IMT. OVH for intact females to prevent hormonal imbalances

• Thyroid supplementation evidence exists that it may ↑ vWF concentration and ↓ bleeding tendency. • Hemorrhage is not generally observed until platelet count is <40 000/μL. • Doberman Pinscher, Scottish Terrier, Shetland Sheepdog, Golden Retriever, Pembroke Welsh Corgi, and Standard Poodle

Notes

INFECTIOUS DISEASES Table 6.32 / Infectious Diseases: Brucellosis and Erlichiosis Disease

Presentation

Definition

256

Brucellosis ZOONOTIC

Ehrlichiosis

A disease caused by Brucella canis.This bacterium is transmitted through ingestion or inhalation and can be found in the lymphatic system, genital tract, eye, kidney, and intervertebral discs.

The most common rickettsial disease of dogs caused by Ehrlichia spp. Transmission is most commonly seen through the bite of the brown dog tick, Rhipicephalus sanguineus, or the Lone Star tick, Amblyomma americanum. Mostly found on the Gulf Coast, Eastern Seaboard, midwest, and California.

Clinical Signs

• Abnormal gait, anorexia, ataxia, exercise intolerance, weakness • Male: scrotal swelling or dermatitis, enlarged epididymis, testicular atrophy • Female: abortion, infertility, and vaginal discharge for 1–6 weeks postabortion

• Acute: ataxia, dyspnea, exercise intolerance, oculonasal discharge • Chronic: dyspnea, epistaxis, pallor, spontaneous bleeding, weakness, weight loss

Examination Findings

• Anterior uveitis, ascites, corneal edema, epididymitis, lymphadenopathy, paralysis, paresis, pyrexia, spinal hyperesthesia, splenomegaly

• Acute: lymphadenopathy, organomegaly, pyrexia, vestibular dysfunction • Chronic: arthritis, intermittent limb edema, neurologic signs, organomegaly, pyrexia, uveitis

SECTION THREE: DIAGNOSTIC SKILLS

Table 6.32 / Infectious Diseases: Brucellosis and Erlichiosis (Continued) Disease

Ehrlichiosis

General

• Clinical signs

• History/clinical signs • Ocular examination: retinal detachment and hemorrhage

Laboratory

• Chemistry panel: ↑ globulin and ↓ albumin • Urinalysis: ↑ protein, albumin • RSAT: accurate for negative dogs, detects infected dogs 3–4 weeks after infection • AGID: highly sensitive, detects infected dogs 4–12 weeks after infection • TAT/2ME-TAT: + titers, detects infected dogs 3–4 weeks after infection • Culture: B. canis identification • Cytology, lymph node: nonspecific reactive hyperplasia • Cytology, semen: >80% of sperm are morphologically abnormal, inflammatory cells • Culture, blood, urine, semen, vaginal discharge, aborted fetuses: Brucella isolation and identification

• CBC: acute, thrombocytopenia, anemia (v), leukopenia and chronic, nonregenerative anemia, thrombocytopenia, lymphocytosis, pancytopenia, leukopenia or leukocytosis • Chemistry panel: acute, ↑ globulin, mild ↑ ALT, ALP, BUN, creatinine, ↓ albumin and chronic, ↑ globulin, BUN, creatinine, ↓ albumin • Urinalysis: acute, ↑ protein, specific gravity • IFA: titers >1:10 (2–3 weeks after exposure, titers not available for all species) • PCR, Erlichia test: +, identifying active infections after treatment • ACT: ↑ clotting times • Buffy coat analysis: Erlichia inclusions in WBCs • Cytology, bone marrow: acute, hypercellular, megakaryocytic, chronic, erythroid hyperplasia, ↑ mast cells

Imaging

• Radiography, spine: diskospondylitis, if found then check for Brucellosis

• N/A

Procedures

• N/A

• N/A

General

• Supportive

• Supportive • Blood transfusion • Fluid therapy

Medication

• Antibiotics: minocycline, gentamicin, doxycycline, enrofloxacin, streptomycin

• Anabolics: oxymetholone, nandrolone decanoate, danazol, stanozolol • Antibiotics: tetracycline, doxycycline, chloramphenicol, imidocarb diproprionate • Corticosteroids: prednisone, prednisolone

Nursing Care

• Treated as outpatient.

• Restrict activity.

Patient Care

• Multiple courses of antibiotic treatment • Serologic titers monthly for 3 months, then at 6 months • Restrict activity in working dogs

• Restrict activity. • Platelet count every 3 days until normal • Repeat serologic testing in 9 months; should be undetectable in 12 months.

Prevention/ Avoidance

• Neuter infected animals. • Quarantine and test all new dogs and breeding individuals.

• Tick control and avoidance through sprays and spot-ons • Avoid tick-infested areas.

Complications

• Infertility • Sexual transmission

• N/A

Prognosis

• Early detected ↑ response to therapy • Guarded if late detection

• Excellent • Poor if bone marrow is severely hypoplastic

Diagnosis Treatment Follow-Up

Brucellosis ZOONOTIC

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Table 6.32 / Infectious Diseases: Brucellosis and Erlichiosis (Continued) Disease Notes

Brucellosis ZOONOTIC • Transmission is following breeding or abortion, or following contact with semen, vaginal discharge, and urine by penetration of oronasal, conjunctival, or genital mucous membranes. • Lasts for 6–64 months • Low risk of human infection with proper hygiene, mild and easily treated

Ehrlichiosis • Transmitted by the brown dog tick and transfusions. • Incubation period is 7–21 days. • German Shepard and Doberman Pinscher

6 Table 6.33 / Infectious Diseases: Rocky Mountain Spotted Fever and Salmon Poisoning Rocky Mountain Spotted Fever ZOONOTIC

Salmon Poisoning

Definition

This is a tick-borne disease caused by Rickettsia rickettsii. It is the most important rickettsial disease in humans. Found on the East Coast, midwest, and Plains region.

A rickettsial disease caused by Neorikettsia helminthoeca and found in the Pacific Northwest. Attacks the tissue of the small intestinal epithelium and associated lymph system.

Clinical Signs

• Abnormal gait, anorexia, ataxia, convulsions, depression, diarrhea, dyspnea, epistaxis, face and limb edema, lethargy, myalgia, weakness

• Diarrhea, hypothermia, naso-ocular discharge, profound weight loss, vomiting

Examination Findings

• Anterior uveitis, arthritis, ascites, conjunctivitis, lymphadenopathy, ocular pain, petechial hemorrhages, pyrexia, scleral injection, tachycardia, vasculitis, vestibular signs

• Conjunctivitis, lymphadenopathy, pyrexia, tachycardia

General

• History/clinical signs • Ticks recently removed from the dog

• History/clinical signs • Recent ingestion of raw salmonoid fish meat

Laboratory

• CBC: eukocytosis with a left shift, +/− toxic neutrophils, monocytosis, mild anemia, thrombocytopenia • Chemistry panel: ↑ ALT, ALP, BUN, creatinine, cholesterol, albumin, ↓ sodium, chloride, protein, metabolic acidosis • Urinalysis: ↑ protein, blood • Micro-IFA: titers >1 : 128 • Direct immunofluorescence with skin biopsies: rickettsial antigens as early as 3–4 days postinfection • ACT: ↑ clotting times

• Urinalysis: ↑ specific gravity • Direct fecal smear: operculated fluke eggs (Nanophyetus salminicola) • Giemsa-stained FNA of lymph nodes: hyperplasia with intracytoplasmic rickettsial bodies in macrophages

Imaging

• N/A

• N/A

Procedures

• N/A

• N/A

Diagnosis

Presentation

Disease

258

SECTION THREE: DIAGNOSTIC SKILLS

Table 6.33 / Infectious Diseases: Rocky Mountain Spotted Fever and Salmon Poisoning (Continued)

Follow-Up

Treatment

Disease

Rocky Mountain Spotted Fever ZOONOTIC

Salmon Poisoning

General

• Supportive • Blood transfusions • Fluid therapy

• Supportive

Medication

• Antibiotics: tetracycline, doxycycline, chloramphenicol, imidocarb diproprionate

• Antibiotics: tetracyclines, chloramphenicol • Anticestodal: praziquantel

Nursing Care

• Restrict activity.

• Restrict activity.

Patient Care

• Monitor platelet count every 3 days until normal. • Micro-IFA titers 2–4 weeks after initial titer: 2–4 fold rise in titer • Restrict activity.

• Monitor temperature, hydration, electrolytes, and acid-base balances.

Prevention/Avoidance

• Tick and rodent control • Using gloves or instruments, check daily for ticks and remove entire tick if found.

• Prevent eating of raw fish (salmonoid type). • Thoroughly cook or freeze fish.

Complications

• N/A

• N/A

Prognosis

• Good if early diagnosis and treatment • Poor if in later stages with CNS disease

• Good with treatment

• Caution: Handling of an infected tick may result in transmission of the disease even without attachment. • Transmitted by the American deer tick, wood tick, Lone Star tick, and transfusions • The tick must be attached for 5–20 hours to infect dogs. • Primary host is rodents and rabbits • Incubation time is 2 days to 2 weeks. • High titers can be seen for 1 year following successful treatment.

• Transmitted through eating raw salmon or related fish carrying encysted forms of the fluke N. salminicola. • Incubation of 5–21 days

Notes

6

Table 6.34 / Infectious Diseases: Tetanus and Toxoplasmosis Disease

Presentation

Definition

Tetanus

Toxoplasmosis ZOONOTIC

Disease caused by Clostridium tetani which is found in the soil and as part of the normal bacterial flora of the intestinal tract of mammals.

This disease, caused by the protozoan parasite, Toxoplasma gondii, can invade and multiply in any cell in the body.

Clinical Signs

• Ataxia, convulsions, disoriented, dyspnea, ears erect, forehead wrinkled, hypersalivation, lips retracted, localized or generalized muscle rigidity, seizures, stiffness, tetanic spasms, trismus, walking difficulty, weakness

• Subclinical most of the time • Anorexia, ataxia, depression, diarrhea, dyspnea, exercise intolerance, lethargy, paralysis, paresis, seizures, stiff gait, tremors, vomiting, weakness, weight loss

Examination Findings

• Altered heart and respiratory rates, hyperventilation, laryngeal spasms, pyrexia, tachycardia

• Abdominal effusion and pain, anterior and posterior uveitis, blindness, icterus, myocarditis, pancreatitis, pneumonia, pyrexia

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Table 6.34 / Infectious Diseases: Tetanus and Toxoplasmosis (Continued) Disease

Tetanus • Clinical signs • Recent wound (esp. with high levels of necrosis and anaerobic conditions)

• Clinical signs

Laboratory

• Chemistry panel: ↑ CK (CPK)

• CBC: leukopenia with degenerative left shift or neutrophilic leukocytosis and nonregenerative anemia • Chemistry panel: ↑ bilirubin, bile acids, AST, ALT, ALP, GGT, creatinine, amylase, lipase, ↓ albumin • Urinalysis: ↑ protein and bilirubin • IgM: elevated 2 weeks postinfection, >1 : 256 or >1 : 64 and negative IgG indicates active infection • IgG: elevated 2–4 weeks postinfection, >1 : 512 active infection or 2–4 fold rising titer 2 weeks apart • Antigen serum titers: + 1–4 weeks postinfection

Imaging

• N/A

• Radiographs, abdominal: hepatomegaly, effusion • Radiographs, thoracic: effusion, patchy alveolar and interstitial pulmonary infiltrates

Procedures

• N/A

• ECG: arrhythmia, cardiac irregularity

General

• Supportive • Fluid therapy • Wound management: debridement, H2O2 flushing, cleaning

• Supportive • Fluid therapy

Medication

• Antibiotics: penicillin G or metronidazole • Anticonvulsants/muscle relaxants: diazepam, chlorpromazine, acetylpromazine, phenobarbital, pentobarbital, methocarbamol • Tetanus antitoxin

• Antibiotics: clindamycin, pyrimethamine, trimethoprimsulfonamide • Folic acid, yeast • Ophthalmic drops: 1% prednisone

Nursing Care

• Keep patient in a dark quiet area and do not disturb. • Provide soft bedding and rotate every 4 hours to prevent decubital sores and lung congestion. • Prevent urinary and fecal retention with urinary catheterization and enemas. • Nutritional support: force feeding is not advised because it may cause tetanic state. • Monitor blood pressure and ECG.

• Typically treat as outpatients. • Confine patients with neurologic signs.

Patient Care

• N/A

• Examine 2 and 14 days post initiation of treatment for improvement. • Provide a high-quality diet, biannual physical examinations, annual blood work, vaccines, and prompt attention to illness.

Diagnosis

General

Follow-Up

Treatment

6

260

Toxoplasmosis ZOONOTIC

SECTION THREE: DIAGNOSTIC SKILLS

Table 6.34 / Infectious Diseases: Tetanus and Toxoplasmosis (Continued)

Follow-Up

Disease

Tetanus

Toxoplasmosis ZOONOTIC

Prevention/ Avoidance

• Prevent skin wounds: maintain clean and safe runs and yards. • Give proper wound care management. • Aseptic surgical technique

• Prevent ingestion of raw meat, bones, viscera, or unpasteurized milk. • Prevent free roaming to hunt prey or access to the housing of food-producing animals.

Complications

• N/A

• N/A

Prognosis

• Extremely guarded when severely affected

• Guarded: can be become carriers and relapse clinically if immunocompromised

• Clinical signs show up 5 days to 3 weeks later. • Death is from respiratory dysfunction. • Animals can be pretested for anaphylactic reaction to the antitoxin by giving an intradermal injection first and monitoring for 30 minutes.

• Caution: Disease can be transmitted to an unborn fetus by an infected human mother. • Transmitted by ingesting infected animal tissues, cat feces, and transplacental infection • Excrete eggs 3–10 days after infection for 1–2 weeks: can shed again if stressed. • Oocysts must first sporulate to become infectious. • Oocysts can last in the soil for >1 year.

Notes

6

MUSCULOSKELETAL Table 6.35 / Musculoskeletal: Arthritis Disease

Arthritis Acute

Diagnosis

Presentation

Definition

Degenerative Joint Disease (DJD, Osteoarthritis)

There are two types of clinically diagnosed arthritis: degenerative and acute inflammatory. Acute arthritis is a pathogenic organism within the closed space of a joint and is broken down into 3 types: septic, traumatic, and immune-mediated. DJD is a progressive deterioration, characterized by a loss of hyaline cartilage matrix and death of chondrocytes. There is no cure for DJD; treatment is based on alleviating clinical signs and slowing progression.

Clinical Signs

• Joint swelling, lameness, pain, reluctance to jump or climb stairs, stiff gait

• Abnormal gait, ataxia, exercise intolerance, ↑ lameness following moderate to heavy exercise, stiff upon rising after recumbency, swelling, walking difficulty

Examination Findings

• Crepitus, laxity, pain, ↓ ROM

• Crepitus, edema, laxity, muscle atropy, pain

General

• History/clinical signs • Joint palpation and manipulation

• History/clinical signs • Joint palpation

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Table 6.35 / Musculoskeletal: Arthritis (Continued) Disease

Degenerative Joint Disease (DJD, Osteoarthritis)

Laboratory

• • • • • • • • •

• Synovial fluid analysis: ↑ mononuclear cells (e.g., lymphocytes), protein, ↓ viscosity, cell count (compared to septic or inflammatory arthritides) • Mucin clot test: clot poor

Imaging

• Radiograph, affected joint: joint capsular distension, soft tissue thickening, joint effusion and bone lysis

• Radiograph, affected joint: osteophytes, subchondral sclerosis, narrowed joint space, and remodeling of subchondral bone/ epiphyses

Procedures

• Arthrocentesis

• Arthrocentesis

General

• Supportive • Surgery: arthrotomy, reconstructive procedures, arthrodesis

• Supportive • Surgery: resection arthroplasty, joint replacement, arthrodesis

Medication

• Antibiotics: variable • Chondroprotective agents: Adequan, glucosamine with chondroitin sulfate • Corticosteroids: prednisone or triamcinolone • Methyl sulfonyl methane • Misoprostol • NSAIDs: aspirin, carprofen, deracoxib, etodolac, firocoxib, meloxicam, tepoxalin

• • • •

Nursing Care

• Standard postoperative • Treated as outpatient

• Standard postoperative • Treated as outpatient

Patient Care

• Moderate activity, but restricted to a level that minimizes discomfort • Strict confinement with acutely painful episodes • Obesity control • Physical therapy: hot/cold treatment, swimming, ROM exercises and massage

• Weight control • Encourage moderate and consistent exercise (e.g., swimming—low impact)

Prevention/ Avoidance

• Maintain appropriate weight control. • Early recognition to prevent proceeding to secondary condition

• Maintain proper weight control. • Early use of glucosamine with chondroitin sulfate to slow progression

Complications

• Nonambulatory • DJD • Osteomyelitis

• Nonambulatory

Prognosis

• Good with septic form • Fair to guarded with immune-mediated form

• Progressive

Diagnosis

Acute

Follow-Up

Treatment

6

262

Arthritis

CBC: leukocytosis, neutrophilia Urinalysis: ↑ protein ANA test: + results Tick-borne agent serology: + results Synovial fluid analysis: ↑ WBCs and bacteria Biopsy, synovial: neoplasia Cytology, synovial: ↑ WBCs, turbidity, bacteria Culture, synovial: bacteria, yeast, fungi, additional organisms Mucin clot test: clot poor

SECTION THREE: DIAGNOSTIC SKILLS

Chondroprotective agents: glucosamine with chondroitin sulfate Corticosteroids: prednisone or triamcinolone Misoprostol NSAIDs: aspirin, carprofen, deracoxib, etodolac, firocoxib, meloxicam, tepoxalin

Table 6.36 / Musculoskeletal: Cruciate Disease and Hip Dysplasia Cruciate Disease (Cranial Cruciate Rupture)

Hip Dysplasia

Definition

Cruciate disease results in a partial or complete instability of the stifle joint. The tearing of the anterior cruciate ligament can be done acutely or as a degenerative process.

Hip dysplasia is the most common condition of the hip joint and cause of osteoarthritis. Hip dysplasia is a faulty development of the hip joint contributing to joint laxity and subluxation early in life. Joint instability occurs as muscle development and maturation lag behind the rate of skeletal growth.

Clinical Signs

• Abnormal gait, acute or intermittent lameness, ataxia, walking difficulty

• Abnormal gait, ataxia, exercise intolerance, hindlimb lameness

Examination Findings

• Deformed stifle joint, edema, joint effusion, muscle atrophy of hindlimb musculature, swelling

• Barden’s sign, Barlow’s sign, crepitus, joint laxity, muscle atrophy, Ortolani + test, pain, ↓ ROM

General

• History/clinical signs • Joint palpation: + anterior drawer sign

• History/clinical signs • Joint palpation

Laboratory

• Synovial fluid analysis: rule out sepsis and immune-mediated disease

• N/A

Imaging

• Radiograph, stifle joint: joint effusion with capsular distention, periarticular osteophytes, compression of infrapatellar fat pad and calcification of cruciate ligament • MRI: confirmation and severity of disease

• Radiographs, skeletal: joint subluxation of femoral head, flattening of femoral head, shallow acetabulum, periarticular osteophytes, or widening of joint space between femoral head and cranial acetabulum

Procedures

• Arthrocentesis • Arthroscopy: confirmation and severity of disease

• N/A

General

• Symptomatic • Cage rest • Surgery: tibial plateau leveling osteotomy (TPLO), “over-the-top” fascia lata graft, fibular head transposition imbrication procedure, extracapsular reinforcing procedures

• Surgery: triple pelvic osteotomy (TPO), femoral head and neck excision arthroplasty, pectineal myectomy, intertrochanteric osteotomy, or total hip replacement

Medication

• Chondroprotective drugs: Adequan, glucosamine with chondroitin sulfate • Misoprostol • NSAIDs: aspirin, carprofen, deracoxib, etodolac, firocoxib, meloxicam, tepoxalin

• Analgesics: variable • Chondroprotective agents: Adequan or glucosamine with chondroitin sulfate • Corticosteroids: prednisone, triamcinolone (short-term use) • Misoprostol • NSAIDs: aspirin, piroxicam, carprofen, etodolac, phenylbutazone, meclofenamic acid

Nursing Care

• Placement of Robert Jones bandage

• Postoperative radiographs to evaluate surgery • Physical therapy • Restrict activity.

Treatment

Diagnosis

Presentation

Disease

6

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263

Table 6.36 / Musculoskeletal: Cruciate Disease and Hip Dysplasia (Continued)

Follow-Up

Disease

6

Cruciate Disease (Cranial Cruciate Rupture)

Hip Dysplasia

Patient Care

• Cryotherapy • Physical therapy: ROM exercises and massage • Restricted activity: leash only exercise and no use of stairs for 3 months postoperative • Reradiograph at 8 weeks • Full exercise by 6–9 months postoperative • Control obesity

• Restrict activity. • Monitor radiographs to assess degeneration.

Prevention/ Avoidance

• Selective breeding • Maintain proper weight control.

• Selective breeding • Nutritional manipulation for large breed dogs during growth and development • Avoid excessive exercise.

Complications

• Osteoarthritis

• Osteoarthritis • Nonambulatory

Prognosis

• Excellent with surgery

• Good depending on severity of disease

Notes

• Joint is palpated for drawer motion, movement of tibia relative to femur during the tibial compression test, and thickening of joint capsule. • In 30–40% of canines, the opposite cranial cruciate ligament ruptures within 17 months. • Rottweiler and Labrador Retriever

Table 6.37 / Musculoskeletal: Osteochondrosis and Osteomyelitis Osteochondrosis or Osteochondritis Dessicans (OCD)

Osteomyelitis

Definition

Osteochondrosis is a defect in endochondral ossification leading to an excessive retention of cartilage. This defect may occur in any limb joint. Ununited anconeal process and fragmented coronoid process may also be seen along with osteochondrosis or separately. It is often seen in animals between 5–10 months of age.

Osteomyelitis is an infection of the bone and its soft tissue elements and membranes. Infectious organisms often complicate an existing condition leading to an infection that is very difficult, and sometimes impossible, to treat.

Clinical Signs

• Abnormal gait, anorexia, cachexia, forelimb or hindlimb lameness, reluctance to exercise, walking difficulty

• Anorexia, cachexia, depression, exercise intolerance, lameness, lethargy, rising difficulty, weakness

Examination Findings

• Arthritis, crepitus, hyperextension pain, joint effusion, joint pain, muscle atrophy, swelling

• Edema, inflammation, intermittent draining tracts, pain, paralysis, paresis, pyrexia, swelling, tachycardia

General

• History/clinical signs • Joint palpation

• History/clinical signs • Skeletal palpation • Neurologic examination

Diagnosis

Presentation

Disease

264

SECTION THREE: DIAGNOSTIC SKILLS

Table 6.37 / Musculoskeletal: Osteochondrosis and Osteomyelitis (Continued)

Follow-Up

Treatment

Diagnosis

Disease

Osteochondrosis or Osteochondritis Dessicans (OCD)

Osteomyelitis

Laboratory

• Joint tap and fluid analysis: confirms involvement and mononucleated cells

• CBC: neutrophilic leukocytosis • Cytology: toxic neutrophils, phagocytized bacteria or fungal organisms • Culture: bacteria isolation and identification and sensitivity

Imaging

• Radiographs, skeletal: joint abnormalities, bone lengths, arthritis, sclerosis of underlying bone or bone flap/fragments (joint “mice”) • CT/MRI: location and severity of lesion • Arthrogram: identifies cartilage flap or loose cartilage via contrast enhanced joint radiographs after intraarticular injections

• Radiographs, skeletal: soft tissue swelling, bone resorption, sclerosis, bone sequestra, fracture nonunion, cortical thinning, widening of fracture gap, reactive periosteal new bone, foreign bodies, or fungal lesions • Contrast: sinus location and severity, foreign bodies • Radionuclide imaging: detecting osteomyelitis

Procedures

• Arthroscopy: confirming cartilage lesion

• N/A

General

• Symptomatic • Surgery: arthrotomy or arthroscopy

• Symptomatic • Wound management: debridement, drainage and irrigation • Surgery: sequestrectomy, amputation, bone grafts, or biopsy

Medication

• Analgesics • NSAIDs

• Antibiotics: variable

Nursing Care

• Cryotherapy postoperative • Place modified Robert Jones bandage.

• Sterile dressing applied to surgical wounds left to close by 2º intention. • Irrigate daily with sterile saline.

Patient Care

• Cryotherapy for 15–20 minutes 3 times daily for 3–5 days if no bandage placed • Physical therapy: ROM exercises • Restrict activity for 4 weeks, then gradually increase to normal activity over the next 4 weeks. • Reradiograph 4–6 weeks postoperative • Obesity management

• Monitor radiographs for fracture healing.

Prevention/ Avoidance

• Selective breeding • Maintain proper weight control. • Nutritional manipulation for large-breed dogs during growth and development

• Proper wound and fracture management

Complications

• Osteoarthritis • Disuse atrophy

• Recurrence and relapse • Limb deformity or impaired function • Neurologic disease

Prognosis

• Good with early surgical repair (forelimb) • Guarded with stifle or tarsal OC

• Good with acute disease • Poor with chronic disease

• Great Dane, Labrador Retriever, Newfoundland, Rottweiler, Bernese Mountain Dog, English Setter, and Old English Sheepdog

• Saint Bernard, German Shepard, Labrador Retriever, Golden Retriever, and Rottweiler

Notes

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265

Table 6.38 / Musculoskeletal: Patella Luxation and Panosteitis Patellar Luxation, Medial

Panosteitis (Enostosis)

Definition

Medial patellar luxation is generally a concern of small breed dogs. It is typically a congenital or developmental malformation of the stifle joint causing the patellar to displace from the femoral trochlea. Luxations are graded on a scale of I–IV, which allows guidance of treatment options.

Panosteitis is a disease of young large-breed dogs that begins in the medullary bone marrow in the region of the nutrient foramen. Its cause is unknown. It gives intermittent lameness of one or multiple limbs. The disease is self-limiting, but its clinical signs will remain for months.

Clinical Signs

• Abnormal gait, ataxia, intermittent lameness of hindlimb, skipping, walking difficulty

• Anorexia, ataxia, cachexia, depression, forelimb and hindlimb lameness, lethargy, shifting leg lameness, walking difficulty

Examination Findings

• Arthritis, pain, stifle joint deformity

• Pain on palpation of diaphysis, pyrexia

General

• History/clinical signs • Patella palpation: laxity

• History/clinical signs • Bone palpation

Laboratory

• N/A

• CBC: eosinophilia (v)

Imaging

• Radiographs, hindlimb: bowing and/or torsion of tibia or femur and shape of femoral trochlea

• Radiograph, skeletal: ↑ density, progressive mottling and radiopacity within the medullary cavity, new bone formation and thickened bone cortices • Scintigrams, bone: bone lesions

Procedures

• N/A

• N/A

General

• Supportive • Symptomatic • Surgical: trochleoplasty, trochlear sulcoplasty, recession sulcoplasty, trochlear chondroplasty, chondroplasty, wedge recession, patelloplasty or tibial tuberosity translocation

• Supportive

Medication

• Analgesics • Chondroprotective agents: Adequan or glucosamine with chondroitin sulfate • Corticosteroids: prednisone (short-term use) • Misoprostol • NSAIDs: aspirin, carprofen, etodolac, piroxicam

• • • •

Nursing Care

• Cryotherapy immediately postoperative then 15–20 minutes daily for 3–5 days if no bandage • Placement of Robert Jones bandage • Physical therapy: ROM exercises and swimming

• Treated as outpatient

Patient Care

• Restricted activity: leash only exercise and no use of stairs for 3 months postoperative • Full exercise by 6–9 months postoperative • Correct obesity

• Restrict activity • Recheck lameness every 2–4 weeks for more serious orthopedic problems

Presentation

Disease

Follow-Up

Treatment

Diagnosis

6

266

SECTION THREE: DIAGNOSTIC SKILLS

Analgesics Corticosteroids: prednisone Misoprostol NSAIDs: aspirin, piroxicam, carprofen, etodolac

Table 6.38 / Musculoskeletal: Patella Luxation and Panosteitis (Continued)

Follow-Up

Disease

Patellar Luxation, Medial

Panosteitis (Enostosis)

Prevention/ Avoidance

• Selective breeding • Maintain proper weight control

• N/A

Complications

• Recurrence following surgery • DJD

• N/A

Prognosis

• Excellent with surgery

• Excellent

• Miniature and Toy Poodle, Yorkshire Terrier, Pomeranian, Pekingese, Chihuahua, and Boston Terrier

• German Shepard, Irish Setter, Saint Bernard, Doberman Pinscher, Airedale, Basset Hound, and Miniature Schnauzer

Notes

6

NEUROLOGY Table 6.39 / Neurology: Encephalitis and Epilepsy Encephalitis

Epilepsy

Definition

Encephalitis is an inflammatory disease of the brain with random progression. The causes of this condition are wide ranging from breed predilections to infectious diseases to viral, protozoan, fungal, and bacterial infections. The clinical signs, diagnosis, and treatment are all dependent on determining the underlying disease.

Epilepsy is a condition of recurring seizures regardless of their cause. Primary epilepsy has no known cause and may be genetic/ hereditary. Secondary epilepsy is acquired through brain injury and/or inflammation.

Clinical Signs

• Dependent on underlying disease • Aggression, ataxia, behavioral changes, circling, depression, head tilt, pacing, paralysis, photophobia, seizures, tremors, vomiting

3 Stages of Seizures • Aura: immediately preceding seizure, restlessness, crying and hiding • Ictus: actual seizure, lasting <2–5 minutes, stiff, muscle spasms, chomps its jaw, salivates profusely, urinates, defecates, vocalizes and paddles with all four paws • Postictus: immediately following seizure – lasting <30 minutes, behavioral changes, weakness, blindness, hungry, thirsty, depressed, pacing, or tired

Examination Findings

• Abnormal heart and respiratory rates, corneal changes, nystagmus, pulmonary abnormalities, pyrexia

• Postictus signs

General

• History/clinical signs • Neurologic examination

• History/clinical signs • Neurologic examination

Laboratory

• • • • •

• N/A

Diagnosis

Presentation

Disease

CBC: leukocytosis and dependent on underlying disease Chemistry panel: ↑ protein, creatine kinase CSF analysis: ↑ WBCs, protein, fungi, bacteria CSF titers: + results Serology: antibody recognition and identification

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Table 6.39 / Neurology: Encephalitis and Epilepsy (Continued)

Diagnosis

Disease

Encephalitis

Epilepsy

Imaging

• Radiographs, thoracic: lung abnormalities • Radiographs, skull: sinusitis or rhinitis (cryptococcosis) • CT/MRI: tumor

• • • • •

Procedures

• EEG: diffuse multifocal cerebral involvement • Ophthalmoscopy: retinitis, chorioditis, uveitis, or vasculitis of retinal vessels

• EEG: tumor, inflammation or metabolic disease • Ophthalmoscopy: retinitis, chorioditis, uveitis, or vasculitis of retinal vessels

General

• Symptomatic • Supportive • Radiation therapy

• • • •

Medication

• • • • •

Dependent on underlying disease Antibiotics: enrofloxacin, clavamox Corticosteroids: dexamethasone Fungal: itraconazole or fluconazole Lomustine

Acute (IV/IN) • Anticonvulsants: diazepam, lorazepam, midazolam, phenobarbital, sodium pentobarbital, felbamate, zonisamide • Propofol Chronic (oral) • Anticonvulsant: gabapentin, phenobarbital, felbamate, potassium bromide

Nursing Care

• • • •

Dependent on underlying disease Monitor neurologic functions. Frequent turning to prevent decubital sores and pulmonary edema Cold water, alcohol baths, or ice packs for hyperthermia

• Constant monitoring for seizures, hyperthermia • Cold water, alcohol baths, or ice packs for hyperthermia

Patient Care

• Monitor neurologic functions. • Monitor blood work dependent on underlying disease.

• Avoid swimming. • Monitor CBC, chemistry panel, urinalysis, phenobarbital, bromide, bile acids annually • Maintain a log of all seizure activity and review biannually with veterinarian.

Prevention/ Avoidance

• Tick control • Vaccinations • Proper wound management

• Castrate affected animals. • Maintain antiseizure medication.

Complications

• Dependent on underlying disease • Death

• Phenobarbital complications • Status epilepticus

Prognosis

• Variable: dependent on underlying disease • Many forms are lethal

• Proper treatment gives ↓ seizure frequency

Follow-Up

Treatment

6

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SECTION THREE: DIAGNOSTIC SKILLS

Radiographs, thoracic: tumors Radiographs, abdominal: tumors Radiographs, skull: hydrocephalus, trauma or tumor CT: tumor, inflammation or granulomas MRI: tumor, inflammation

Symptomatic Oxygen therapy Ocular compression Fluid therapy: do not give lactated Ringer’s in patients receiving potassium bromide

Table 6.39 / Neurology: Encephalitis and Epilepsy (Continued) Disease

Encephalitis

Epilepsy

Notes

• Caution: Chosen drugs must be able to cross the blood-brain barrier. • Determining the underlying cause is critical to the patient’s survival.

• Ocular compression is the gentle compression of the globe into the orbit by digital pressure over the upper lid for 10–60 seconds at 5-minute intervals. • Most seizures occur while sleeping or at rest, often at night or in early morning. • Do not stop medications abruptly as it may cause seizures; slowly reduce over 4–8 weeks (taper gradually). • German Shepard, Irish Setter, Miniature Poodle, Siberian Husky, Beagle, Cocker Spaniel, Labrador Retriever, Keeshond, and Miniature Schnauzer

6

Table 6.40 / Neurology: Intervertebral Disc Disease and Meningitis Intervertebral Disc Disease

Meningitis

Definition

Intervertebral disc disease is an age-related condition affecting an individual disc or discs. This condition may lead to protrusion or extrusion of the disc leading to compression of the spinal cord, nerve roots, or meninges. The process can be either a degenerative or infectious process (diskospondylitis).

Bacterial infection of the meninges is the cause of meningitis. It can be the result of septicemia, local invasion, or bite wounds. Secondary inflammation of the brain or spinal cord may also be seen with meningitis.

Clinical Signs

• Abnormal gait, ataxia, crying when touched, paresis or paralysis of some or all limbs, reluctance to move or jump, stiff or hunched stance/appearance, urinary incontinence, walking difficulty

• Ataxia, cachexia, convulsions, depression, dyspnea

Examination Findings

• Edema, pain, Schiff-Sherrington syndrome

• Ataxia, cervical pain and rigidity, edema, hyperesthesia, nasal, sinus or inner ear infection, mild paresis, pyrexia, tachycardia, tremors

General

• History/clinical signs • Spine palpation

• History/clinical signs • Neurologic examination

Laboratory

• Urinalysis: leukocytes, ↑ protein, bacteria • CSF analysis: inflammatory cells and infectious agents

• • • • •

Diagnosis

Presentation

Disease

CBC: leukocytosis Chemistry panel: ↑ globulin Urinalysis: pyuria, ↑ bacteria Serology tests: + Cytology, skin, eyes, nasal discharge and sputum: bacterial, fungal, protozoan, rickettsial, or viral • CSF analysis: bacteria, neutrophilic pleocytosis, protein

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Table 6.40 / Neurology Intervertebral Disc Disease and Meningitis (Continued) Disease

Diagnosis

Imaging

Intervertebral Disc Disease

Meningitis

• Radiographs, spine: narrowed, wedge-shaped disc space, small intervertebral foramen, collapsed articular facets or mineralized disc material in the spinal cord, intervertebral foramen or vertebral endplate lysis or sclerosis • CT/MRI: location and severity of disc lesion, spinal cord edema • Myelography: location and severity of disc lesion

• Radiographs, spine: bony infection • Radiographs, skull: sinus, nasal cavity, or ear infection • MRI/CT: ↓ opacity of cerebral hemisphere, lack of contrast

Procedures

Follow-Up

Treatment

6

General

• • • •

Medication

• Corticosteroids: prednisone, prednisolone or methyl prednisolone succinate

• • • •

Nursing Care

• Careful handling of patients to prevent further trauma: protect the spine during any movement • Nutritional support • Monitor for worsening neurological signs. • Monitor urine output and defecation. • Turn recumbent patients at least every 4 hours and keep well padded.

• Intensive care monitoring • Restricted activity

Patient Care

• Restrict activity. • Physical therapy: ROM exercises, hydrotherapy, start 2 weeks postoperative • Monitor urinalysis in nonambulatory patients. • Use harnesses to keep pressure off cervical discs. • Obesity management

• Monitor for neurologic signs, fever, systemic signs, and leukocytosis.

Prevention/ Avoidance

• Maintain proper weight control. • Avoid strenuous exercise with prone breeds.

• Treat local infections early and thoroughly to prevent spread of infection to the CNS.

Complications

• Recurrence of pain

• Irreversible damage to the brain and spinal cord • DIC

Prognosis

• Excellent with surgery

• Variable dependent on degree of infection and inflammation

Notes

270

• N/A Symptomatic Cage rest for 2 weeks Acupuncture Surgery: laminectomy, hemilaminectomy, durotomy, decompression

• Caution: Corticosteroids should not be used with diskospondylitis. • Caution: Do not use corticosteroids and NSAIDs together due to GIT hemorrhage. • For confinement to work, it must be strict with only leash walks to eliminate. • Beagle, Toy Poodle, Dachshund, Doberman Pinscher, and all chondrodystrophic breeds SECTION THREE: DIAGNOSTIC SKILLS

• Symptomatic • Supportive • Fluid therapy Antibiotics: variable Anticonvulsants: diazepam or phenobarbital Corticosteroids: dexamethasone, prednisolone Diuretics: mannitol (osmotic type)

Table 6.41 / Neurology: Myasthenia Gravis and Myelopathy Myasthenia Gravis

Myelopathy (Degenerative Myelopathy)

Definition

Myasthenia gravis is associated with autoantibodies directed at nicotinic acetylcholine receptors (AChRs). This leads to a loss of AChRs, which impairs neuromuscular transmission and causes muscle weakness and episodic collapsing.

Myelopathy is a degenerative process affecting the myelin and axons of the spinal cords. This slow, progressive problem has no known cause but is limited to the hindlimbs. There is no known treatment; it remains to be only supportive.

Clinical Signs

• Abnormal gait, body trembling, dysphagia, excessive drooling, dysphonia, dyspnea, muscle weakness, paresis/paralysis, regurgitation

• Abnormal gait, ataxia, crossing over of hindlimbs, knuckling, scuffing of hindlimbs, swaying when turning, walking difficulty, weakness, worn toenails

Examination Findings

• Masticatory dysfunction, ventroflexion of head

• Muscle atrophy

General

• History/clinical signs (episodic) • Neurologic examination

• History/clinical signs • Neurologic examination

Laboratory

• • • • •

Chemistry panel: ↑ CK Thyroid and adrenal function tests ANA assay: + result Serum antibodies against nicotinic AChRs: + result Edrophonium chloride challenge test: ↑ muscle strength following injection • Edrophonium response test: + • Electrodiagnostic evaluation: location and severity of disease

• CSF analysis: ↑ protein, WBCs

Imaging

• Radiographs, thoracic: megaesophagus, cranial mediastinal mass, aspiration pneumonia

• Radiographs, thoracic: metastasis and tumors • Radiographs, abdominal: same as above • Radiographs, spine: ossification, spondylosis or narrowed intervertebral disc space • MRI: to rule out IVDD

Procedures

• Fluoroscopy: dysfunction of swallowing

• N/A

General

• • • •

• Supportive

Medication

• Anticholinesterase drugs: pyridostigmine bromide or neostigmine • Corticosteroids: prednisone • Cyclophosphamide

• Aminocaproic acid (v) • N-Acetylcysteine (v) • Vitamin supplements: vitamin C, E

Nursing Care

• Nutritional support

• Treated as outpatient

Patient Care

• Feed animal in an upright position and ensure the animal remains upright for at least 10 minutes after eating. • Feed different consistencies of food to determine which works best. • Radiograph every 4–6 weeks to monitor megaesophagus. • Recheck AChR antibody titers every 6–8 weeks until normal.

• Keep as active as possible to delay onset of nonambulatory state. Nonambulatory • Cart, slings for mobility • Avoid decubital sores • Urinary catheter • Vitamin supplementation

Follow-Up

Treatment

Diagnosis

Presentation

Disease

Supportive Fluid therapy Oxygen therapy Surgery: feeding tube placement or tumor removal

6

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Table 6.41 / Neurology: Myasthenia Gravis and Myelopathy (Continued)

Follow-Up

Disease

Myasthenia Gravis

Myelopathy (Degenerative Myelopathy)

Prevention/ Avoidance

• N/A

• N/A

Complications

• Aspirate pneumonia • Third-degree heart block • Respiratory arrest

• Decubital sores • Fecal and urine incontinence

Prognosis

• Good • Guarded with cranial mediastinal mass

• Guarded to poor • Patients eventually lose function of both hindlimbs and front limbs.

• Jack Russell Terrier, Springer Spaniel, Smooth Fox Terrier, Golden Retriever, German Shepard, Labrador Retriever, Dachshund, and Scottish Terrier

• German Shepard, Collie, Labrador Retriever, Chesapeake Bay Retriever, Kerry Blue Terrier, and Pembroke Welsh Corgi

Notes

6

Table 6.42 / Neurology: Vestibular Disease and Wobbler Syndrome Vestibular Disease of Older Dogs, Acute

Wobbler Syndrome (Caudal Cervical Spondylomyelopathy, Cervical Vertebral Instability)

Definition

Vestibular disease is an acute condition affecting geriatric dogs. It is the disturbance of the peripheral vestibular system. Otitis media is a common cause of the disease in younger dogs.

Wobbler syndrome is due to pressure placed on the spinal cord by malformation of bone or spinal ligaments. It leads to instability or chronic disc disease. It is thought that overnutrition and rapid growth may be a contributing factor to this condition.

Clinical Signs

• Anorexia, asymmetrical ataxia, circling, disorientation, falling, head tilt toward the affected side, loss of balance, nausea, nystagmus, rolling, vomiting

• Abnormal gait, ataxia, dragging of toes, knuckling, paraparesis and ambulatory or nonambulatory tetraparesis, rigid flexion of neck, walking difficulty

Examination Findings

• Facial paresis or paralysis, Horner’s syndrome, strabismus

• ↓ Proprioception, pain, supraspinatus atrophy

General

• Clinical signs • Neurologic examination • Otoscopic examination: fluid, ruptured or bulging tympanum

• History/clinical signs

Laboratory

• N/A

• N/A

Imaging

• Radiographs, skull: osseous bullae fluid, sclerosed, osteitis • MRI/CT: tumor, osseous bullae sclerosed

• Radiographs, spine: bony changes, herniation, subluxation or narrowing of intervertebral disc space • Myelogram: site and type of cord compression

Procedures

• BAER: evaluation of cochlear portion of cranial nerve VIII

• CSF analysis: ↑ protein • Thyrotropin stimulation test: minimal to no response

Diagnosis

Presentation

Disease

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SECTION THREE: DIAGNOSTIC SKILLS

Table 6.42 / Neurology: Vestibular Disease and Wobbler Syndrome (Continued)

Follow-Up

Treatment

Disease

Vestibular Disease of Older Dogs, Acute

Wobbler Syndrome (Caudal Cervical Spondylomyelopathy, Cervical Vertebral Instability)

General

• Supportive • Fluid therapy

• Supportive • Surgery: ventral spondylectomy, dorsal laminectomy, fenestration, stabilization or fusion of involved vertebrae

Medication

• Antibiotics: trimethoprim-sulfa, cephalexin, cefadroxil, enrofloxacin, orbifloxacin • Antiemetics: dimenhydrinate, meclizine • Tranquilizers: diazepam

• Corticosteroids: prednisone, methylprednisone sodium succinate, dexamethasone • Muscle relaxant: methocarbamol, diazepam

Nursing Care

• Treated as outpatient

• • • •

Urinary catheter in nonambulatory patients Avoid decubital sores. Physical therapy of all limbs to prevent ankylosis Restrict activity of ambulatory patients or use a neck brace.

Patient Care

• Restrict activity as needed for disorientation. • Reexam 2–3 days after discharge to verify continued improvement.

• Monitor neurologic functions. • Physical therapy

Prevention/ Avoidance

• Prompt recognition and treatment of ear infections if present

• Limit running and jumping. • Use harness instead of a neck collar.

Complications

• Dehydration • Electrolyte imbalances • Renal insufficiencies

• • • •

Prognosis

• Excellent • Most patients return to normal in 2–3 weeks.

• Good when presented ambulatory • Poor when nonambulatory with tetraparesis

Notes

6

Failure of surgical repair Degenerative changes of surrounding disc spaces Decubital sores Urinary tract infection or urine scalding

• Caution: Flexion and tension stress during radiographs can make clinical signs worse. • Great Dane and Doberman Pinscher

ONCOLOGY Table 6.43 / Oncology: Neoplasia Neoplasia

Definition

Neoplasia is the development of a new and abnormal formation of tissue, as a tumor or growth. It serves no useful function but grows at the expense of the healthy organism.

Presentation

Disease

Clinical Signs

• Presence of a tumor or 2 effects attributable to adjacent organ/tissue injury (e.g., halitosis, swelling, pain) • Anorexia, depression, diarrhea, inappetance, lethargy, vomiting, weight loss

Examination Findings

• Detection of tumor, variable (e.g., lymphadenopathy, organomegaly, hyperemic mucous membranes) and additional disorders

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Table 6.43 / Oncology: Neoplasia (Continued) Disease

• History/clinical signs • Physical examination: tumor and lymph node palpation

Laboratory

• • • • • •

CBC: variable (see specific tumor type), anemia: normocytic and normochromic Chemistry panel: variable (see specific tumor type) Urinalysis: variable (see specific tumor type) Fine needle aspirate, core biopsy, or surgical biopsy of tumor or enlarged lymph node(s) Cytology: cells fulfilling the criteria for malignancy Histopathology: clean margins and tumor grade

Imaging

• • • •

Radiographs, thoracic (VD and left and right laterals): tumor identification, metastases, lymphadenopathy, pleural effusion Radiographs, abdominal: tumor identification, metastases, lymphadenopathy, organomegaly Ultrasound: tumor identification, lymphadenopathy, guided biopsy MRI/CT: tumor identification, metastases, lymphadenopathy, tumor margins, tissue of origin

Procedures

• Variable

General

• • • • • •

Symptomatic Fluid therapy Radiation therapy Cryosurgery Photodynamic therapy Surgery: excision with 2–3 cm clean margins

Medication

• • • •

Variable (see specific tumor type) Chemotherapy agents Corticosteroids Analgesics

Nursing Care

• Standard postoperative following surgical excision

Patient Care

• Variable (see specific tumor type) • Monitor specific blood values • Monitor response to treatment, chemotherapy (see Skill Box 8.13, page 356) appetite, elimination, and energy level

Prevention/ Avoidance

• N/A

Complications

• Variable (see specific tumor type)

Prognosis

• Dependent on tumor type, size, location, time of discovery, and completeness of excision

Diagnosis

General

Follow-Up

Treatment

6

274

Neoplasia

SECTION THREE: DIAGNOSTIC SKILLS

Table 6.44 / Oncology: Histiocytoma, Mammary Gland Neoplasia, and Mast Cell Tumor Disease

Histiocytoma (Button Tumor)

Mammary Gland Neoplasia

Mast Cell Tumor

Definition

A histiocytoma is a benign skin tumor often found on the head, ear pinna, and limbs. They are most commonly seen in dogs less than 2 years of age.

Mammary gland neoplasia is very prevalent among female, intact dogs and very rare in male dogs. The tumors show malignancy 50% of the time. If the tumors are malignant, they have usually metastasized by the time of diagnosis.

Mast cell tumors are malignant tumors that arise from mast cells. They are a very unpredictable tumor in their appearance, growth rate, and response to treatment.

• Fast growing, firm, small, dome- or button-shaped mass, fast growing, solitary, nonpainful, ± ulcerated

• Firm nodular mass, ± ulceration • Nipples: red, swollen, and exudate (e.g., tan, red) • Fever

Dogs • Lymphadenopathy, erythema, and edema • Tumor: solitary skin or SQ mass, present for days to months, recent rapid growth Cats • Anorexia and vomiting • Tumor: found in SQ tissue or dermis, papular or nodular, solitary or multiple, hairy or alopecic and/or ulcerated

Presentation

Clinical Signs

Diagnosis

Examination Findings

• Edematous hindlimbs

• Lymphadenopathy, hepatomegaly, intestinal wall thickening, splenomegaly

General

• Clinical signs

• Clinical signs • Mammary gland palpation

• History/clinical signs

Laboratory

• Cytology: pleomorphic round cells, variable sized and shaped nuclei, appearance of hepatocytes, variable amounts of pale blue cytoplasm resembling monocytes, ± lymphocyte, plasma cell, and neutrophil infiltrate

• CBC: anemia and leukocytosis • Cytology: cells with cytoplasmic basophilia, variable nuclear/cytoplasmic ratios and if malignant have typical carcinoma clumps (e.g., acinar)

• CBC: eosinophilia, basophilia (v), anemia and mastocythemia (rare) • Buffy coat smear: mast cells • Cytology: round cells with basophilic cytoplasmic granules not forming sheets or clumps and ± eosinophilic infiltrate • Biopsy: confirmation and severity of disease • Histopathology: confirmation of completeness of excision

Imaging

• N/A

• Radiographs, thoracic: pleural effusion and lung metastases • Radiographs, abdominal: ascites and ↑ size of sublumbar lymph nodes • Ultrasound: ascites and size of sublumbar lymph nodes

• Radiographs, abdominal: ↑ spleen, liver, and lymph nodes • Ultrasound: visceral metastasis

Procedures

• N/A

• N/A

• Lymph node aspirates • Darier’s sign: a tumor that has been manipulated will degranulate causing erythema and wheel formations.

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6

Table 6.44 / Oncology: Histiocytoma, Mammary Gland Neoplasia, and Mast Cell Tumor (Continued)

Treatment

Disease

Histiocytoma (Button Tumor)

Mammary Gland Neoplasia

Mast Cell Tumor

General

• Spontaneous regression • Surgery: excision or cryosurgery

• Symptomatic • Surgery: mastectomy

• • • • •

Medication

• N/A

• Chemotherapy: doxorubicin, cyclophosphamide, and mitoxantrone

• Chemotherapy: L-asparaginase, vinblastine, cyclophosphamide, lomustine, and vincristine • Corticosteroids: prednisone • GI protectants: sulcralfate • H1-blockers: diphenhydramine • H2-blockers: cimetidine, ranitidine

Nursing Care

• Standard postoperative

• Standard postoperative

• Standard postoperative

Patient Care

• Monitor its growth and the presence of new tumors.

• Reexam every 2 months for reoccurrence of mammary tumors.

• Monitor CBC and lymph node enlargement before each chemotherapy administration. • Monitor for the presence of new tumors.

Prevention/ Avoidance

• N/A

• Early hysterectomy: ≤2nd heat cycle

• N/A

Complications

• N/A

• • • • • •

• • • •

Prognosis

• Excellent

• Dependent on size, time of detection, and completeness of excision

• Dependent on the area affected, time of detection, and completeness of excision • Metastasis to regional lymph nodes, liver, spleen, and bone marrow

• Boxer, Dachshund, Cocker Spaniel, Great Dane, and Shetland Sheepdog

• Freely movable tumor implies benign, and fixed to body wall or skin implies malignant. • Removal of all 4 glands of the affected chain is recommended.

• Animals with tumors on the extremities tend to live longer than do animals with trunk tumors. • Boxer, Boston Terrier, Bullmastiff, English Setter, and Siamese cats

Follow-Up

6

Notes

276

SECTION THREE: DIAGNOSTIC SKILLS

Anemia Ascites DIC Hypercalcemia Osteoporosis Pleural effusion

Symptomatic Chemotherapy Radiotherapy Cryosurgery (grade I, small, cutaneous) Surgery: aggressive excision and splenectomy

Bleeding Chemotherapy toxicity Hemorrhagic gastroenteritis Radiation reaction

Table 6.45 / Oncology: Various Neoplasias Type of Cancer

Clinical Signs

Diagnosis

Treatment

Follow-Up

Complications

Prognosis

• Dyschezia, tenesmus, PU/PD, pruritis, ulceration, bleeding, weakness, and paresis

• Chemistry panel: ↑ calcium, ↓ phosphorus • PTH/PTHrP: ↑ values • Radiographs, thorax: metastasis (nodules) • Radiographs, abdominal: enlarged lymph nodes, fluid • Ultrasound, abdominal: enlarged lymph nodes, liver or spleen nodules • Biopsy: confirmation

• Chemotherapy: cisplatin (canine), carboplatin, doxorubicin • Calcitonin • Diruetics: furosemide • Fluid therapy • Radiation therapy • Surgery: tumor and lymph node excision/debulking

• Examination, radiographs, ultrasound and blood work every 3 months following surgery

• • • • •

• Poor

CARCINOMA Adenocarcinoma Anal Sac • Mostly seen in geriatric female dogs with a very high rate of metastasis

Fecal incontinence Metastasis Renal failure Reoccurrence Sepsis

6

Nasal • Most tumors begin as unilateral but progress to bilateral

• Epistaxis, epiphora, sneezing, nasal discharge, halitosis, and seizures • Facial deformity: nasal bone swelling

• Radiographs, skull: tumor location, extent • Radiograph, thorax: metastasis (nodules) • MRI/CT or Rhinoscopy: tumor location, extent and effect on surrounding structures and biopsy • Mycotic cultures: fungal rhinitis • Biopsy: confirmation

• Antiemetic: butorphanol • Chemotherapy: cisplatin (canine), cyclophosphamide, piroxicam, vincristine • Radiotherapy • Surgery: tumor excision/debulking

• Survey radiographs, CT or MRI when clinical signs return

• Brain involvement across cribiform plate

• Fair with radiation • Poor with brain involvement

Pancreas • Liver metastasis is very common.

• Ascites, icterus, maldigestion • Palpable abdominal mass, pyrexia

• CBC: mild anemia, neutrophilia • Chemistry panel: ↑ amylase, lipase • Radiograph, abdominal: metastasis, fluid, ascites • Ultrasound, abdominal: tumor, pancreatitis • Biopsy: confirmation

• Palliative • Surgery: tumor excision

• Monitor quality of life

• Diabetes insipidus • Intestinal or biliary obstruction • Pancreatic abscess • Pancreatitis • Peritonitis

• Grave

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Table 6.45 / Oncology: Various Neoplasias (Continued) Type of Cancer

Clinical Signs

Diagnosis

Treatment

Follow-Up

Complications

Prognosis

Prostate • Prostrate tumors are always malignant.

• Cachexia, constipation, dyschezia, dyspnea, dysuria, exercise intolerance, rear limb lameness, stranguria, tenesmus • Hematuria, pyrexia

• CBC: inflammatory leukogram • Chemistry panel: ↑ alk phos, azotemia • Urinalysis: pyuria, ↑ blood, malignant epithelial cells • Radiography, thorax: metastasis • Radiograph, abdominal: lesions, prostrate changes, lymphadenopathy • Ultrasound, abdominal: prostate changes (asymmetry) • Contrast cystography: distortion of prostatic urethra

• Analgesics: NSAIDs or opioid drugs • Chemotherapy: cisplatin (canine), carboplatin, doxorubicin • Radiotherapy • Stool softeners • Surgery: prostate excision, castration

• Monitor ability to urinate and defecate. • Monitor pain levels.

• Constipation • Metastasis • Urethral obstruction

• Grave

Salivary Gland

• Dysphagia, pain on opening mouth, swelling of upper neck, ear base, upper lip, maxilla, mucous membrane of lip

• Radiographs, thorax: metastasis • Biopsy: confirmation

• Radiotherapy • Surgery: tumor excision

• Monitor for tumor growth every 3–6 months.

Thyroid • High rate of metastasis • Biopsy and FNA can cause excessive bleeding. • Rare in felines

• Dysphagia, dysphonia, dyspnea, PU/PD, regurgitation • Firm, nonpainful cervical mass, tachycardia • See Canine Hypothyroidism signs

• CBC: nonregenerative anemia • Radiographs, cervical: displacement of normal structures • Ultrasound, thorax: disease extent • CT: disease extent • Radioiodine study: thyroid hormone production • T4, T3, TSH concentrations • Thyroid gland scintigraphy: location

• β-Blockers • Analgesics: butorphanol • Chemotherapy: doxorubicin, cisplatin, carboplatin • Methimazole • Radioactive iodine (feline) • Radiotherapy • Surgery: tumor, gland, lymph node excision • Thyroxin (secondary hypothyroidism)

• Examination tumor site and radiographs every 3 months • Monitor calcium, thyroid concentration levels.

6

278

SECTION THREE: DIAGNOSTIC SKILLS

• Unknown

• • • • • •

Anemia DIC Hypoparathyroidism Hypothyroidism Laryngeal paralysis Respiratory distress

• Dependent on size of tumor and lymph node involvement • Larger fixed tumors have a poor prognosis.

Table 6.45 / Oncology: Various Neoplasias (Continued) Type of Cancer

Clinical Signs

Diagnosis

Treatment

Follow-Up

Complications

Prognosis

Squamous Cell Carcinoma Digit • Often seen in large, black dogs • Arises from subungual epithelium

• Chronic and progressive lameness, swelling, ulceration

• Radiographs, affected foot: lysis of the 3rd phalanx

• Chemotherapy: cisplatin (canine), mitoxantrone, bovine collagen matrix with 5-fluorouracil • Piroxicam • Retinoids • Surgery: wide margin amputation

• Limit sun exposure. • Use sunscreen or tattoo on low pigmented areas of the paws.

• Good

Ear • Areas of low pigmentation and those subjected to solar radiation are more at risk.

• Crusty eczematous lesions on edge of pinna, ulceration

• Biopsy: confirmation

• Bleomycin • Chemotherapy: cisplatin (intralesional injections) • Cryosurgery • Etretinate • Hyperthermia • Photodynamic therapy • Radiotherapy • Surgery: amputation/ pinnectomy ± ablation of ear canal • Vitamin E

• Limit sun exposure. • Use sunscreen or tattoo on low pigmented areas of the ears.

• Good with complete excision

Gingiva

• Bloody oral discharge, dysphagia, excessive salivation, halitosis, loose teeth, and facial deformity • Plaque-like areas that bleed easily

• Radiographs, skull: bone involvement and lysis • Radiographs, thorax: metastasis • CT: bone involvement and lysis • Biopsy: confirmation

• Chemotherapy: cisplatin (canine), mitoxantrone, carboplatin • Cryosurgery • Photodynamic therapy (PDT) • NSAIDs: piroxicam, ± meloxicam • Radiotherapy • Surgery: tumor excision/debulking

• Feed soft foods or by enteral feeding tube.

• Poor due to local invasion (feline) • The more rostral the tumor is located, the better is the prognosis (canine).

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6

Table 6.45 / Oncology: Various Neoplasias (Continued) Type of Cancer

Clinical Signs

Diagnosis

Treatment

Follow-Up

Skin • Areas of low pigmentation and those subjected to solar radiation are more at risk. • Malignant tumor of squamous epithelium

• Crusty, pigmentation, ulceration • Facial skin involvement (feline), nail bed involvement (canine)

• Radiographs, extremity: bone involvement • Radiographs, thorax: metastasis • Biopsy: confirmation

• Chemotherapy: cisplatin (canine), carboplatin, mitoxantrone, bovine collagen matrix with 5fluorouracil (canine) • Cryosurgery • Photodynamic therapy • Radiotherapy • Retinoids • Surgery: tumor excision/debulking

• Reexam and radiographs every 3 months for 1 year, then every 6 months for 1 year. • Limit sun exposure. • Use sunscreen or tattoo low pigmented areas of the skin.

• Dysuria, hematuria, pollakiuria, PU/PD, recurrent stranguria, tenesmus, urinary incontinence

• Chemistry panel: azotemia if at trigone • Urinalysis: ↑ blood, malignant epithelial cells • Urine culture: UTI • Radiograph, thorax: metastasis • Double contrast cystography: irregularities or mass lesions • IV pyelography, voiding urethrogram or vaginogram • Ultrasound, abdomen: extent of disease, proximity to trigone

• Chemotherapy: cisplatin (canine), carboplatin, mitoxantrone • NSAIDs: piroxicam, meloxicam • Radiotherapy

• Cystography or ultrasonography every 6–8 weeks • Thoracic radiographs every 2–3 months

• Transplantation of cells during surgery or biopsy • Urinary incontinence, urethral or ureteral obstruction, renal failure

• Grave

• Lameness, nasal discharge • Pain, swelling

• Radiograph, affected limb: lesion • Radiograph, thorax: metastasis • CT scan: extent of disease • Nuclear bone scan: staging of disease • Biopsy: definitive diagnosis

• Chemotherapy: cisplatin (canine), carboplatin, doxorubicin • Radiotherapy • Surgery: tumor excision, amputation

• Thoracic radiographs monthly for 3 months, then every 3 months

• Brain involvement

• Poor to excellent, dependent on tumor grade

6

Complications

Prognosis • Good with superficial lesions • Guarded with nail bed or digit involvement

Transitional Cell Carcinoma Bladder, Urethra • High rate of metastasis • FNA may cause seeding of tumor cells along the needle tract.

SARCOMA Chondrosarcoma Bone • Affects large breed dogs

280

SECTION THREE: DIAGNOSTIC SKILLS

Table 6.45 / Oncology: Various Neoplasias (Continued) Type of Cancer

Clinical Signs

Diagnosis

Treatment

Follow-Up

Complications

Prognosis

Nasal and Paranasal Sinus • Affects large breed dogs

• Epiphoria, halitosis, nasal discharge, seizures, sneezing • Facial deformity, pain

• Radiographs, skull: tumor, fluid, and destruction of caudal turbinates • MRI/CT: integrity of cribiform plate and orbital invasion

• Chemotherapy: doxorubicin • Radiotherapy • Surgery: tumor excision/debulking

• Radiographs and CT/MRI may be repeated when clinical signs return.

• Fair • Poor with brain involvement (cribriform plate destruction)

• Fracture, lameness, pain, swelling

• Radiograph, affected limb: lesion • Radiograph, thorax: metastasis • CT: extent of disease • Biopsy: definitive diagnosis

• Chemotherapy: cisplatin (canine), carboplatin, doxorubicin • Radiotherapy • Surgery: tumor excision, amputation

• Thoracic radiographs monthly for 3 months, then every 3 months

• Guarded

• Bloody oral discharge, dysphagia, excessive salivation, halitosis • Facial deformity, loose teeth

• Radiographs, skull: bone involvement • Biopsy: intraoral

• Chemotherapy: doxorubicin, cisplatin • Cryosurgery • Radiotherapy • Surgery: tumor excision/debulking

• Feed soft foods

• Fair with early detection and aggressive treatment

• Fracture, lameness, pallor, swelling

• CBC: regenerative anemia, nucleated RBCs, poikilocytosis, anisocytosis, thrombocytopenia, leukocytosis, ↓ protein • FDP, PT, and PTT: ↑ values • Fibrinogen: ↓ values • Radiographs, bone: lysis • Radiographs, thorax: metastasis • Ultrasound: metastasis • CT: extent of disease

• Chemotherapy: doxorubicin, cyclophosphamide • Surgery: tumor excision, amputation

• Examination, thoracic radiographs and ultrasound every 3 months for 1 year then every 6 months

Fibrosarcoma Bone • Primarily affect the axial skeleton

Gingiva

6

Hemangiosarcoma Bone

• Pathologic fractures • Rupturing tumors causing hemorrhage

• Unknown

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Table 6.45 / Oncology: Various Neoplasias (Continued)

6

Type of Cancer

Clinical Signs

Diagnosis

Treatment

Follow-Up

Complications

Prognosis

Heart • Pulmonary metastasis very common

• Dyspnea, exercise intolerance, syncope, weight loss • Abdominal and pleural effusion, arrhythmia, hepatomegaly, hindlimb paresis, jugular distention, pulse deficits

• CBC: anemia, nucleated RBCs • Chemistry panel: azotemia • Ultrasound, thorax: location of tumor • Biopsy, heart: definitive diagnosis

• Chemotherapy: doxorubicin, vincristine, cyclophosphamide • Pericardial and pleuralcentesis • Surgery: tumor excision/debulking

• Examination, thoracic radiographs and ultrasound monthly

• Centesis, surgery complications

• Guarded to poor

Spleen, Liver • Rapid growth and widespread metastatic vascular neoplasia

• Ataxia, dementia, intermittent collapse, lameness, paresis, seizures, weakness • Enlarged abdomen, pale mucous membranes, peritoneal fluid, tachycardia

• CBC: regenerative anemia, polychromasia, reticulocytosis, nucleated RBCs, anisocytosis, leukocytosis, neutrophilia, thrombocytopenia • Chemistry panel: ↑ liver enzymes • FDP, PT, and PTT: ↑ values • Radiograph, abdomen: tumor detection, fluid • Radiograph, thorax: metastasis • Ultrasound, heart: tumor location and metastasis

• Antihistamines: diphenhydramine • Biological response modifier L-MTP-PE • Blood transfusions • Chemotherapy: cyclophosphamide, doxorubicin, chlorambucil, methotrexate, vincristine • Fluid therapy • Surgery: splenectomy

• Restrict activity • Thoracic and abdominal radiographs and abdominal ultrasound every 3 months

• Sepsis • Skin sloughs • Tumor rupture leading to hemorrhage • Vomiting and diarrhea

• Poor

• CBC: anemia, leukocytosis, and lymphoblastosis • Chemistry panel: ↑ creatinine, BUN, ALT, AST, calcium • Urinalysis: ↑ bilirubin, protein, isothenuria • Serology: + FeLV • Cobalamin and folate: ↓ values • Ultrasound, abdominal • Cytology: bone marrow, tumor, lymph nodes • Histopathology: clean margins and tumor grade

• Chemotherapy: vincristine, cytosine arabinoside, methotrexate, cyclophosphamide, chlorambucil, L-asparaginase, doxorubicin, actinomycin-D • Corticosteroids: prednisone • Surgery

• Examination, CBC and platelet count before each weekly cycle of chemotherapy

• Leukopenia • Sepsis

• Dependent on form

Lymphosarcoma/Lymphoma Feline • Most common sites are alimentary tract, anterior mediastinum, liver, spleen, and kidneys.

282

• Dependent on form (mediastinal, renal, alimentary, solitary or multicentric) • Coughing, open mouth breathing, regurgitation, weight loss • Renal failure signs, thickened intestines

SECTION THREE: DIAGNOSTIC SKILLS

Table 6.45 / Oncology: Various Neoplasias (Continued) Type of Cancer

Clinical Signs

• Canine • Seen most commonly is solid tissues: lymph nodes, bone • marrow and visceral organs • ↑ Risk with exposure to the herbicide: 2,4dichlorophenoxyacetic

Coughing, drooling, dysphagia, dyspnea, exercise intolerance Anterior uveitis, ascites, lymphadenopathy, lymphoid infiltrate, organomegaly

Diagnosis

Treatment

Follow-Up

Complications

Prognosis

• CBC: anemia, lymphocytosis, lymphopenia, neutrophilia, monocytosis, circulating blasts, and thrombocytopenia • Chemistry panel: ↑ ALT, ALP, and calcium • Echo: cardiac contractility • Ultrasound, abdominal • Cytology: bone marrow, tumor, lymph nodes • Histopathology: clean margins and tumor grade • Immunochemical staining of lympocytes

• Chemotherapy: doxorubicin, vincristine, epirubicin, cyclophosphamide, L-asparaginase, methotrexate, chlorambucil • Corticosteroids: prednisone • Fluid therapy • Radiotherapy • Retinoids • Surgery • Thoraco- and abdominocentesis

• Restrict activity of patients with ↓ WBCs or platelet count. • Monitor CBC and platelet count during chemotherapy. • Echo and ECG: cardiotoxicity of doxorubicin

• Alopecia • DIC • Leukopenia and neutropenia • Pancreatitis • Sepsis • Tissue sloughing • Vomiting and diarrhea

• Good

6

Osteosarcoma • Most common bone tumor in dogs, typically affecting the appendicular skeleton of large to giant breeds

• Lameness, pain, swelling • Pathologic long bone fracture

• Radiograph, affected bone: bone lysis, proliferation in the metaphyseal region of long bones, soft tissue swelling • Nuclear bone scans: bony or soft tissue metastatic disease

• Analgesics: butorphanol, piroxicam, fentanyl, morphine sulfate • Biological response modifiers: L-MTP-PE • Chemotherapy: cisplatin (canine), carboplatin, doxorubicin • Radiotherapy • Surgery: amputation

• Restrict activity. • Monitor radiographs every 2–3 months. • Monitor CBC and platelet count 7–10 days after chemotherapy.

• Metastasis (>90% of cases at examination) and hypertrophic osteopathy

• Guarded once metastases is present

Vaccine-Induced Sarcoma • Typically fibrosarcoma, but may be many other types of sarcoma •Most common with FeLV and rabies

• Firm, painless, SQ swelling located at a previous vaccination site

• Radiograph, tumor site: bone lysis or extension of the tumor along other tissue planes • Radiograph, thorax: metastasis check • Contrast CT scan: extent of disease • Biopsy: confirm diagnosis • Histopathology: clean margins and tumor grade

• Chemotherapy: doxorubicin, cyclophosphamide • Radiotherapy • Surgery

• Evaluate monthly for 3 months, then every 3 months. • Monitor CBC and platelet count before each chemotherapy treatment.

• Recurrence, new lesions

• Poor

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283

OPHTHALMOLOGY Table 6.46 / Ophthalmology: Anterior Uveitis and Cataracts Disease

Presentation

Definition

Treatment

Diagnosis

6

284

Anterior Uveitis

Cataracts

Anterior uveitis is inflammation of the iris and ciliary body. Corneal ulceration, trauma, autoimmune, lens-induced, or infections can cause anterior uveitis, but the disease may also be primary.

Cataracts are pathological changes in the eye that lead to opacity. The changes are in the lens protein composition or disruption of lens fiber arrangement. The general causes are hereditary, inflammatory, metabolic, traumatic, nutritional, or toxic.

Clinical Signs

• Blepharospasm, blindness, elevation of nictitating membrane, epiphora, inappetence, lethargy, miosis, photophobia, redness, tearing

• Blindness, visual impairment

Examination Findings

• Aqueous flare, conjunctival hyperemia, hypotony, corneal edema, fibrinous exudate

• Aqueous flare, any opacity in the lens of a dilated eye, synechia

General

• Clinical signs • Ophthalmic examination

• History/clinical signs • Ophthalmic examination

Laboratory

• Chemistry panel: ↑ globulin • Serology: toxoplasmosis, Bartonella, FeLV, FIP, FIV, FHV-1

• Serology: systemic mycoses, rickettsial disease, brucellosis, toxoplasmosis, FeLV, FIV

Imaging

• Radiographs, thoracic: tumors or evidence of fungal disease • Radiographs, abdominal: tumors • Ultrasound, ocular: foreign body and penetrating wounds

• Ultrasound, ocular: retinal detachment

Procedures

• Tonometry: ↓ pressure or ↑ pressure when secondary to glaucoma

• • • •

General

• Symptomatic

• Supportive • Surgery: phacoemulsification, extracapsular extraction, and implantation of an intraocular lens • Laser surgery: capsulotomy

Medication

• Antibiotics: clindamycin • Corticosteroids (systemic): prednisone • Corticosteroids (topical): 1% prednisolone acetate, 0.1% dexamethasone • Mydriatic-cycloplegic: 0.5–1% atropine • NSAIDs: 0.03% flurbiprofen, 1% suprofen, Rimadyl, Deramaxx, meloxicam

• • • •

Nursing Care

• Treated as outpatient

• Treated as outpatient • Standard postoperative (e.g., monitor in flammation) • Pain management

SECTION THREE: DIAGNOSTIC SKILLS

Electroretinogram: degree of retinal atrophy Gonioscopy Biomicroscopy Tonometry: ↓ pressure

Corticosteroids: 1% prednisolone acetate Mydriatics: 1% tropicamide NSAIDs Mydriatic-cycloplegic: atropine

Table 6.46 / Ophthalmology: Anterior Uveitis and Cataracts (Continued)

Follow-Up

Disease

Anterior Uveitis

Cataracts

Patient Care

• Reexam 5–7 days after initiation of treatment then every 2–3 weeks • Monitor intraocular pressure

• Examination frequently for several months postoperative, then every 6 months for life

Prevention/ Avoidance

• N/A

• Prompt treatment of uveitis • Selective breeding • Well-balanced nutrition in hand-fed neonates

Complications

• • • • • •

• • • •

Prognosis

• Dependent on severity of disease upon presentation

• Dependent on stage and location of disease and age of animal

• Caution: Corticosteroids are contraindicated in cases of primary conjunctivitis and corneal ulceration. • It takes 2 months for the blood-aqueous barrier to completely heal after an insult; therefore, continue to treat for 2 months.

• Caution: Differentiate from nuclear sclerosis, which is an increase in the clarity of the nucleus of the lens and is a normal aging process. • Special considerations must be taken with medications and procedures for patients with diabetes mellitus. • Miniature Poodle, American Cocker Spaniel, Miniature Schnauzer, Golden Retriever, Boston Terrier, and Siberian Husky and Persian, Birman, and Himalayan cats

Notes

Blindness Secondary glaucoma Cataracts Endophthalmitis or panophthalmitis Iris atrophy Lens luxation

Anterior uveitis Corneal endothelial damage Glaucoma Retinal detachment

6

Table 6.47 / Ophthalmology: Conjunctivitis and Entropion Disease

Entropion

Conjunctivitis is a general term for inflammation of the ocular mucous membrane that covers the sclera and lines the inner surface of the eyelids. Its causes can be infectious, foreign body, trauma, tear film deficiency, chemical or environmental irritants, immune-mediated, or due to other eye diseases.

Entropion is the inward rolling of the eyelid, causing contact of the eyelashes or eyelid hair with the eye.

Clinical Signs

• Discharge, pain

• Blepharospasms, blindness, epiphora, purulent discharge, visual impairment

Examination Findings

• Chemosis, hyperemia, tissue proliferation

• Conjunctivitis, corneal rupture, corneal ulceration

Definition

Presentation

Conjunctivitis

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Table 6.47 / Ophthalmology: Conjunctivitis and Entropion (Continued)

Diagnosis

Disease

• History/clinical signs • Ophthalmic examination

• History/clinical signs • Ophthalmic examination

Laboratory

• Serology: FeLV or FIV • Cytology: inflammation, neoplasia, viral or chlamydial infection • Biopsy: neoplasia or preocular mucin deficiency

• N/A

Imaging

• N/A

• N/A

Procedures

• • • •

General

• Symptomatic • Surgery: keratectomy or removal of foreign body, hairs or mass

• Surgery: correction of anatomic entropion, eyelid eversion suture technique

Medication

• Amino acid: L-lysine (FHV-1) • Antibiotics (systemic): tetracycline, erthyomycin, chloramphenical • Antibiotics (topical): triple antibiotic, oxytetracycline, erythromycin, doxycycline • Antiviral: trifluridine, vidarabine, interferon • Corticosteroids (systemic): megesterol acetate • Corticosteroids (topical): 1% dexamethasone • Lacrimostimulants: hyaluronic acid • NSAIDs

• Antibiotic (topical): triple antibiotic

Nursing Care

• Irrigate the eye with a eyewash solution to remove any exudate. • Clip the hair surrounding the eye. • Apply an Elizabethan collar to prevent self-trauma.

• Treated as outpatient.

Patient Care

• Maintain the eyes clear of exudate. • Examination 5–7 days after initiation of treatment and then as needed

• Do not allow rubbing at eyes/sutures.

Prevention/ Avoidance

• Vaccinate. • Isolate patients with infectious conjunctivitis. • Minimize stress for patients with the herpetic conjunctivitis.

• Selective breeding

Complications

• Corneal sequestration • Symblepharon • Keratoconjunctivitis sicca (KCS)

• Conjunctivitis • Impaired vision

Prognosis

• Excellent with bacterial conjunctivitis • Fair with feline herpesvirus, immune-mediated diseases, or KCS

• Good

• Caution: Corticosteroids are contraindicated in cases of primary conjunctivitis and corneal ulceration.

• Chow, Shar pei, and hunting dogs

Follow-Up

Notes

286

Entropion

General

Treatment

6

Conjunctivitis

Schirmer tear test: ↓ tear production Fluorescein stain: ulceration and nasolacrimal duct patency Culture: bacteria or fungi isolation and identification Tonometry: ↑ pressure

SECTION THREE: DIAGNOSTIC SKILLS

• N/A

Table 6.48 / Ophthalmology: Cilia Disorders and Glaucoma Disease

Presentation Diagnosis Treatment

Glaucoma

Cilia disorders are the abnormal location or positioning of the eyelashes. Trichiasis is cilia arising from normal sites that are directed toward the eye. Distichiasis is the growing of cilia from the meibomian glands and emergence from their ducts. Ectopic cilia are cilia that arise from the meibomian gland and erupt through the palpebral conjunctival surface.

Glaucoma is an increase in intraocular pressure with subsequent damage to the optic nerve. Chronic glaucoma is often caused by retinal and optic nerve degeneration and buphthalmos.

Clinical Signs

• Blepharospasm, discharge, epiphora

• Blepharospasm, blindness, dilated pupil, epiphora, impaired vision, ↑ pupillary light response • Weak to absent menace response

Examination Findings

• Anisocoria, hyperemia, chemosis, pain, pigmentation, tissue proliferation, vascularization

• Buphthalmos, conjunctival hyperemia, corneal edema, luxated lens, retinal degeneration

General

• History/clinical signs • Ophthalmic examination

• History/clinical signs • Ophthalmic examination

Imaging

• N/A

• Radiographs, skull: fungi or neoplastic lesions • Ultrasound, ocular: structural abnormalities

Procedures

• N/A

• Tonometry: ↑ pressure, >25–30 mm Hg (canine) and >31 mm Hg (feline) • Electroretinography: vision loss

General

• Surgery: cryoepilation, electroepilation, tarsoconjunctival resection, facial fold resection, or medial canthal closure

• Supportive • Symptomatic • Surgery: cyclophotocoagulation, gonioimplatation, intraocular prosthesis or enucleation

Medication

• Antibiotics (topical): triple antibiotic

• Adrenergic agents: 0.1% dipivefrin, 0.25–0.5% timolol • Miotics: pilocarpine 2%, demecarium bromide, epinephrine 1%, dipivefrin HCl 0.1%, or timolol maleate 0.5% • Carbonic anhydrase inhibitors: methazolamide, dorzolamide, brinzolamide • Corticosteroids: dexamethasone • Diuretics: 20% mannitol or glycerin • Prostaglandins: latanoprost

Nursing Care

• Treated as outpatient

• Treated as outpatient

Patient Care

• Treat swelling with topical antibiotics, corticosteroids, and/or hypertonic saline.

• Warm, moist compresses twice daily for 5–7 days postoperative • Monitor every 1–2 days for 1 week for improvement. • Treat the other eye prophylactically daily with an autonomic agent.

Definition

Follow-Up

Cilia Disorders (Distichiasis, Trichiasis and Ectopic Cilia)

6

Laboratory

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287

Table 6.48 / Ophthalmology: Cilia Disorders and Glaucoma (Continued)

Follow-Up

Disease

Cilia Disorders (Distichiasis, Trichiasis and Ectopic Cilia)

Glaucoma

Prevention/ Avoidance

• Clip hair on facial folds and around the eyes.

• Yearly ophthalmic examination in predisposed breeds • Examinations 2–3 times a year on unaffected eye when 1 eye already has glaucoma

Complications

• Recurrence • Conjunctivitis • Keratitis

• Blindness • Chronic ocular pain

Prognosis

• Excellent with facial fold resection • Fair to good with hair removal

• Fair with surgery • Poor with medical treatment alone

• Felines do not have cilia, and canines normally only have them on the upper eyelid.

• Normal intraocular pressure is 15–25 mm Hg. • 50% of animals develop glaucoma in the second eye within 8 months of the initial diagnosis. • 40% of dogs will be blind in affected eye within 1 year regardless of treatment. • May take up to 6 weeks for vision to return

Notes

6

Table 6.49 / Ophthalmology: Keratitis and Keratoconjunctivitis Sicca Disease

Presentation

Keratoconjunctivitis Sicca (KCS, Dry Eye Syndrome)

Nonulcerative (Chronic Superficial Keratitis)

Ulcerative (Corneal Ulceration/Erosion)

Keratitis is inflammation of the cornea with possible corneal erosion. It can be caused by trauma, foreign bodies, bacterial infection, irritant, cilia disorders, KCS, feline herpesvirus, or corneal exposure.

Ulceration is the loss of a full-thickness of epithelium with at least some stromal loss. This can be caused by trauma, bacterial infection, pseudomonas, feline herpesvirus, epithelial dystrophy, corneal dryness, neurotrophic keratitis, or complications from other diseases.

KCS is a lack of normal tear production causing drying and inflammation of the cornea and conjunctiva. It is thought to be an immune-mediated disease against the lacrimal gland. It can also be caused by long-term use of sulfonamides.

Clinical Signs

• Blepharospasm, photophobia, prolapsed third eyelid, squinting, rubbing at eyes, serous to mucopurulent discharge, tearing

• Blepharospasm, epiphora, photophobia, rubbing at eyes, serous to mucopurulent discharge

• Blepharospasms, blindness, eye rubbing, mucoid to mucopurulent discharge, periocular crust, photophobia, pruritus

Examination Findings

• Corneal edema, hyperemia, neovascularization, pigmentation

• Aqueous flare, corneal edema, corneal opacity, conjunctival hyperemia, hypotony, miosis, neovascularization, surface depression

• Chemosis, dull, opaque or pigmentation of cornea, hyperemia, superficial vascularization, thickened conjunctiva, ulceration

Definition

288

Keratitis

SECTION THREE: DIAGNOSTIC SKILLS

Table 6.49 / Ophthalmology: Keratitis and Keratoconjunctivitis Sicca (Continued)

Follow-Up

Treatment

Diagnosis

Disease

Keratitis

Keratoconjunctivitis Sicca (KCS, Dry Eye Syndrome)

Nonulcerative (Chronic Superficial Keratitis)

Ulcerative (Corneal Ulceration/Erosion)

General

• History/clinical signs • Ophthalmic examination

• History/clinical signs • Ophthalmic examination

• History/clinical signs • Ophthalmic examination

Laboratory

• Virus isolation: feline herpesvirus

• Virus isolation: feline herpesvirus • Culture: bacteria or fungi isolation and identification

• Cytology: severity of bacterial overgrowth

Imaging

• N/A

• N/A

• N/A

Procedures

• Schirmer tear test: ↓ production • Cytology: recognition and identification of bacteria

• Fluorescein stain: retention of stain • Schirmer tear test: >15 mm/min

• Schirmer tear test: ↓ production, <10 mm/min • Fluorescein stain: retention of stain

General

• Symptomatic • Contact lenses • Plesiotherapy with strontium-90–generated beta-radiation • Surgery: debridement, laceration repair, keratotomy, keratectomy, superficial keratotomy, or conjunctival flap surgery

• Symptomatic • Debridement of ulcer edges • Surgery: conjunctival flap, tissue adhesion, pedicle flap, keratectomy, linear keratotomy, contact lenses and collagen shields

• Symptomatic • Surgery: transposition of the parotid salivary duct

Medication

• 2% Cyclosporine • Antibiotics: chloramphenical, tobramycin, erythromycin, triple antibiotic or gentamicin • Antiviral: trifluridine or idoxuridine • Mydriatic-cycloplegic: atropine • Corticosteroids (topical): 0.1% dexamethasone, 1% prednisolone acetate • Mucolytics: acetylcysteine • NSAIDs: aspirin

• Antibiotics (systemic): variable • Antibiotics (topical): gentamicin, tobramycin and triple antibiotic • Antiprotease agent: acetylcysteine

• Antibiotics (topical): variable • Artificial tears supplementation: hyaluronic acid, hydroxypropyl methycellulose • Immunosuppression: cyclosporine, tacrolimus • Miotics: pilocarpine • Mucolytics: acetylcysteine

Nursing Care

• Treated as outpatient

• With deep ulcer, restrict activity to prevent rupture. • Apply an Elizabethan collar to prevent self-trauma.

• Clean eyes regularly to keep them clear of discharge.

Patient Care

• Exam every 1–2 weeks to monitor progress until resolved.

• Monitor healing process with fluorescein stain every 1–2 days until improvement is seen.

• Monitor Schirmer tear test every 2–4 weeks until normal. • Clean eyes regularly to keep them clear of discharge.

Prevention/ Avoidance

• N/A

• Lubricant ointment administration in brachycephalic (canine) • Continuous treatment with KCS

• N/A

CHAPTER 6 / GENERAL MEDICINE

6

289

Table 6.49 / Ophthalmology: Keratitis and Keratoconjunctivitis Sicca (Continued) Disease

Keratoconjunctivitis Sicca (KCS, Dry Eye Syndrome)

Ulcerative (Corneal Ulceration/Erosion)

Complications

• Blindness • KCS • Keratitis, ulcerative

• • • • • • •

Prognosis

• Dependent on severity of disease may require lifelong treatment

• Fair to good: may take several weeks to heal

• Good with lifelong treatment

• Caution: Corticosteroids are contraindicated in cases of primary conjunctivitis and corneal ulceration.

• Schirmer tear test: at least 15 mm/min of wetting • Acetylcysteine 5% is mixed 1 : 1 with artificial tears for ophthalmic use. • Cocker Spaniel, Bulldog, West Highland Terrier, Lhaso Apso, Miniature Schnauzer, and Shih tzu

Follow-Up

Nonulcerative (Chronic Superficial Keratitis)

Notes

• Keratitis, ulcerative

Descemetocele Chronic ophthalmitis Glaucoma Rupture of globe Endophthalmitis Blindness Phthisis bulbi

Table 6.50 / Ophthalmology: Lens Luxation and Prolapsed Gland of the Third Eyelid Lens Luxation

Prolapsed Gland of the Third Eyelid (Cherry Eye)

Definition

Lens luxation is the actual movement of the lens either anteriorly or posteriorly. It is often caused by glaucoma, uveitis, cataracts, trauma, or primary zonular degeneration.

Cherry eye is caused by a weak attachment to the nictitating membrane gland, allowing it to protrude/prolapse from the leading edge of the third eyelid.

Clinical Signs

• Blepharospasm, epiphora, redness

• Blepharospasms, discharge, epiphora, swelling at medial canthus

Examination Findings

• Aphakic crescent, corneal edema, hyperemia, iridodenesis, pain

• Conjunctivitis, hyperemia

General

• Clinical signs • Ophthalmic examination

• History/clinical signs • Clinical Signs

Laboratory

• N/A

• N/A

Imaging

• Radiographs, thoracic: metastasis from intraocular neoplasia • Ultrasound, ocular: structural abnormalities

• N/A

Procedures

• Wood’s lamp: fluorescence of a clear lens • Tonometry: ↑ values

• N/A

Presentation

Disease

Diagnosis

6

Keratitis

290

SECTION THREE: DIAGNOSTIC SKILLS

Table 6.50 / Ophthalmology: Lens Luxation and Prolapsed Gland of the Third Eyelid (Continued)

Follow-Up

Treatment

Disease

Lens Luxation

Prolapsed Gland of the Third Eyelid (Cherry Eye)

General

• Supportive (posterior luxation) • Surgery (anterior luxation): cyclocryosurgery, evisceration, intrascleral prosthesis or enucleation

• Surgery: repositioning of the nictitating membrane gland and anchoring securely

Medication

• • • •

Mydriatics: 1% tropicamide Miotics: demecarium bromide Carbonic anhydrase inhibitors: dichlorphenamide Corticosteroids (topical): 0.1% dexamethasone, prednisolone acetate • Diuretics: mannitol

• Antibiotics: variable • Corticosteroids (topical): 1% dexamethasone • NSAIDs

Nursing Care

• Treated as outpatient

• Standard postoperative

Patient Care

• Examine within 24 hours and then frequently after that until intraocular pressure stabilizes. • Examine every 3 months.

• Do not allow rubbing at eyes/sutures.

Prevention/Avoidance

• Selective breeding

• Selective breeding

Complications

• • • • • • • •

• Reprolapse of the gland • Infection at surgery site • Corneal ulcer/erosion secondary to suture abrasion

Prognosis

• Good with surgery

• Excellent with surgery

• Caution: Pupil should not be dilated with acute anterior lens luxation. • Poodle, Shar pei, Whippet, Norwegian Elkhound, and terriers

• Cocker Spaniel, Bulldog, Pitbull Terrier, Beagle, Bloodhound, Lhasa Apso, Shih tzu, and Shar pei

Notes

Uveitis Corneal edema Dyscoria Blindness Synechia Glaucoma Retinal detachment Vitreous entrapment in the incision

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291

UROLOGY Table 6.51 / Urology: Cystic Calculi, Feline Lower Urinary Tract Disease, and Pyelonephritis Feline Lower Urinary Tract Disease (FLUTD) (Feline Urologic Syndrome, FUS)

Pyelonephritis (Upper Urinary Tract Infection)

Definition

Any macroscopic concretions found within the urinary bladder are called cystic calculi. They can be found anywhere along the urinary tract, but most commonly seen in the urinary bladder.

FLUTD is inflammation of the lower urinary tract including the bladder and urethra. It is typically idiopathic. It can also occur secondary to bacterial infection, crystalluria, or iatrogenic (e.g., urinary catheterization).

Pyelonephritis is inflammation of the renal parenchyma, collecting diverticula, ureters, and its pelves. It is typically used to refer to a kidney infection and is most commonly secondary to bacterial invasion.

Clinical Signs

• Dysuria, hematuria, malodorous, stranguria, pollakiuria

• Anuria, dysuria, hematuria, licking at perineal area, periuria, pollakiuria, polyuria

• Anorexia, arched back, cachexia, depression, dysuria, hematuria, lethargy, malodorous or discolored urine, pollakiuria, PU/PD, stranguria, vomiting

Examination Findings

• Abdominal pain, dehydration

• Thickened, firm contracted bladder wall

• Abdominal and lumbar pain, dehydration, pyrexia, tachycardia

General

• History/clinical signs: recurrent bacterial UTIs • Bladder palpation (v)

• History/clinical signs • Abdominal palpation: bladder • Perineal examination

• History/clinical signs • Abdominal palpation: kidney

Laboratory

• Chemistry panel: ↑ potassium, BUN, creatinine and metabolic acidosis • Urinalysis: ↑ bacteria, crystals, change in pH (depending on type of crystal) • Urine culture: bacteria isolation and identification • Bile acids or ammonia concentration: ↑ with ammonium urate calculi and portosystemic shunts • Stone analysis and bacterial culture: needed for long term treatment

• Urinalysis: pyuria, ↑ blood, bacteria, crystals • Urine culture: bacteria isolation and identification

• CBC: neutrophilic leukocytosis with a left shift (v) and nonregenerative anemia • Chemistry panel: ↑ BUN, creatinine, phosphorus and azotemia • Urinalysis: pyuria, ↑ bacteria, blood, protein, leukocyte casts, crystals, ↓ specific gravity • Urine culture: bacteria isolation and identification • Cytology, renal pelvis: bacteria and neutrophils

Imaging

• Radiographs, abdominal: radiopaque calculi • Contrast: radiolucent calculi and vesicourachal diverticula • Ultrasound, abdominal: calculi

• Radiographs, abdominal: anatomic abnormalities, calculi, urethral plugs, tumors, or urachal diverticula • Contrast: urethral strictures, tumors, radiolucent uroliths, or vesicourachal diverticula • Ultrasound, abdominal: anatomic abnormalities, calculi, tumors, or urachal diverticula

• Radiographs, abdominal: ↓ size of kidneys and contours (v) • Ultrasound, abdominal: dilation of renal pelves and proximal ureter, kidney size, and nephrolithiasis

Procedures

• N/A

• N/A

• Pyelocentesis

Presentation

Cystic Calculi (Urocystoliths)

Diagnosis

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Disease

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Table 6.51 / Urology: Cystic Calculi, Feline Lower Urinary Tract Disease, and Pyelonephritis (Continued) Cystic Calculi (Urocystoliths)

Feline Lower Urinary Tract Disease (FLUTD) (Feline Urologic Syndrome, FUS)

Pyelonephritis (Upper Urinary Tract Infection)

General

• • • •

Symptomatic Medical dissolution (struvite only) Urohydropulsion Surgery

• Symptomatic

• Symptomatic • Surgery: nephrotomy • Lithotripsy

Medication

• • • •

Allopurinol (ammonium urate) Antibiotics: variable MPG or D-penicillamine (cystine) Urine alkalinizer: potassium citrate

• • • •

• Antibiotics: variable

Follow-Up

Treatment

Disease

• • • • •

Analgesics: butorphanol, buprenorphine Antibiotics: variable Anticholinergics: propantheline Glycosaminoglycan: glucosamine, pentosan polysulfate sodium Methenamine mandelate Phenoxybenzamine Tranquilizers: diazepam Tricyclic antidepressant: amitriptyline Urine acidifier: DL-methionine, ammonium chloride

6

Nursing Care

• Access to clean litter box or frequent walks • Monitor for anuria.

• Access to clean litter box or frequent walks • Monitor for anuria. • Treated as outpatient

• Access to clean litter box or frequent walks • Treated as outpatient

Patient Care

• Monitor urine pH and specific gravity. • Strict diet restrictions depending on type of calculus • Monitor dissolution monthly by radiographs, urinalysis, urine culture, and ultrasonography. • Monitor radiographs every 3–4 months on patients with surgical removal for reoccurrence.

• Culture urine 1 week after beginning treatment. • ↑ Water consumption by feeding canned food mixed with water, adding potassium or sodium chloride to the food or subcutaneous fluids. • Monitor males for urethral obstruction.

• Culture urine 3–5 days and 1 month after beginning treatment. • Perform a urinalysis and urine culture 7 days and 28 days after completing treatment. • ↑ Water consumption by feeding canned food mixed with water, adding sodium chloride to the food or subcutaneous fluids

Prevention/ Avoidance

• Strict diet restrictions depending on type of calculi • Monitor urine pH.

• • • •

• Correct ectopic ureters. • Encourage water consumption.

Complications

• Reoccurrence • Urethral obstruction • Secondary bacterial UTI

• Urethral obstruction (feline, male) • Recurrence

• • • • •

Prognosis

• Excellent with treatment

• Excellent

• Fair to good: may have irreversible kidney damage

Acidifying or low magnesium diet Avoid stress. Encourage water consumption. Maintain a clean litter box.

Chronic renal failure Reoccurrence Nephrolithiasis Septicemia or septic shock Metastatic infection

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Table 6.51 / Urology: Cystic Calculi, Feline Lower Urinary Tract Disease, and Pyelonephritis (Continued) Cystic Calculi (Urocystoliths)

Notes

• Calculi and urine pH • Struvite: alkaline urine • Ammonium urate and silica : neutral to acid urine • Cystine: acid urine • Calcium oxalate: any urine pH

Feline Lower Urinary Tract Disease (FLUTD) (Feline Urologic Syndrome, FUS)

Pyelonephritis (Upper Urinary Tract Infection)

Table 6.52 / Urology: Renal Failure Disease

Presentation

294

Renal Failure Acute (ARF)

Chronic (CRF)

Acute renal failure is the rapid decline in renal function. It is the accumulation of uremic toxins due to filtration failure, dysregulation of fluids, electrolytes, and acid-base balances. Unlike CRF, this condition may be reversible if diagnosed quickly and treated aggressively.

Chronic renal failure is the progressive decline in the function of the kidneys leading to their shutdown over months to years. The damage is irreversible. The causes may be familial, toxins, infections, neoplasia, or infectious disease.

Clinical Signs

• Anorexia, anuria, ataxia, bruising, diarrhea, dyspnea, lethargy, depression, oliguria, polyuria, seizures, tachypnea, vomiting

• Anorexia, blindness, coma, constipation, diarrhea, lethargy, nocturia, PU/PD, seizures, vomiting, dehydration weakness, and exercise intolerance

Examination Findings

• Bradycardia, cardiac abnormalities, dehydration, enlarged painful kidneys, halitosis, hypothermia, nonpalpable urinary bladder, oral ulcerations, pyrexia

• Ascites, dehydration, halitosis, oral ulcerations, small, firm nodular kidneys, subcutaneous edema

General

• History/clinical signs • Abdominal palpation: kidney

• History/clinical signs • Abdominal palpation: kidney

Laboratory

• CBC: leukocytosis with or without a left shift (v), lymphopenia, monocytosis, ↑ PCV and nonregenerative anemia (v) • Chemistry panel: ↑ BUN, creatinine, phosphate, glucose, potassium, alk phos, albumin, lipase, calcium (ARF), ↓ protein, calcium (ethylene glycol) and azotemia • Urinalysis: pyuria, bacteria, crystals, ↑ albumin, glucose, cellular and granular casts, ↓ specific gravity • Protein-to-creatinine ratio: >1 (3–5 severe) • Urine culture: bacteria isolation and identification • Blood gasses: metabolic acidosis • Serology: leptospirosis or ehrlichiosis • Eythlene glycol concentration: + results • Biopsy: confirmation, cause and severity of disease

• CBC: nonregenerative anemia • Chemistry panel: ↑ protein, BUN, creatinine, amylase, lipase, phosphate, ↓ potassium, ± calcium and metabolic acidosis • Urinalysis: ↑ protein (v), ↓ specific gravity • Protein:creatinine ratio: to determine severity of proteinuria and glomerular disease • Culture, urine: bacteria isolation and identification • Biopsy, renal: confirmation, cause and severity of disease

Definition

Diagnosis

6

Disease

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Table 6.52 / Urology: Renal Failure (Continued) Disease

Chronic (CRF)

Imaging

• Radiographs, abdominal: renal size and shape, renal uroliths, peritonitis • Contrast: obstruction or structural rupture • Ultrasound, abdominal: renal uroliths and parenchymal and anatomical abnormalities

• Radiographs, abdominal: renal size and shape and renal uroliths • Contrast: obstruction or structural rupture

Procedures

• Endoscopy: gastric ulcers • Blood pressure: hypertension

• Blood pressure: hypertension

General

• • • • • • • •

• • • • • • •

Diagnosis

Acute (ARF)

Symptomatic Supportive Fluid therapy, ± potassium Hemodialysis Peritoneal dialysis Blood transfusions Poison antidotes (e.g., ethylene glycol) Renal transplantation

Medication

• • • • • • • •

Nursing Care

• • • •

Patient Care

• Monitor blood values until normal. • Nutritional support • Renal diet: ↑ omega-3, omega-6, caloric density, fiber, ↓ highquality protein, phosphorus, sodium • Fresh water at all times to increase water consumption • Subcutaneous fluids for diuresis and hydration

Treatment Follow-Up

Renal Failure

Alkalinizer: sodium bicarbonate Anabolics: testosterone, nandrolone, oxymethalone, stanozolol Antibiotics: variable Antiemetics: trimethobenzamide or chlorpromazine Calcium gluconate Diuretics: 20% mannitol, 20% dextrose, furosemide H2-receptor antagonist: cimetidine or rantidine Phosphate binders: aluminum hydroxide, calcium carbonate, calcium acetate, epakitin • Potassium supplement: potassium chloride, potassium gluconate • Vasodilators: dopamine

Symptomatic Supportive Fluid therapy Hemodialysis Peritoneal dialysis Blood transfusions Renal transplantation

6

• • • • • •

ACE inhibitors: enalapril, benazepril, amlodipine Alkalinizer: sodium bicarbonate Androgens: stanozolol, nandrolone decanoate Erythropoietin: rHuEPO H2-receptor antagonist: cimetidine, famotidine, rantidine Phosphate binders: aluminum hydroxide, calcium carbonate, calcium acetate, epakitin • Potassium supplement: potassium chloride, potassium gluconate • Vitamin D: calcitriol

Nutritional support Monitor urine output, 1–3 mL/min initially. Monitor hydration, temperature, and body weight. Monitor PCV and blood values. • Nutritional support • Renal diet: ↑ omega-3, omega-6, caloric density, fiber, ↓ high quality protein, phosphorus, sodium • Fresh water at all times to increase water consumption • Subcutaneous fluids for diuresis and hydration • Monitor weekly initially, then monitor hydration; weight and blood values every 1–4 months depending on severity of CRF

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Table 6.52 / Urology: Renal Failure (Continued)

Follow-Up

Disease

Renal Failure Acute (ARF)

Chronic (CRF)

Prevention/ Avoidance

• Anticipate ARF in susceptible animals and conduct preventative fluids and medication. • Avoid use of nephrotoxic drugs. • Restrict exposure to antifreeze. • Maintain adequate blood pressure during anesthesia, especially in prolonged procedures and older animals.

• Anticipate ARF in susceptible animals and conduct preventative fluids and medication. • Avoid use of nephrotoxic drugs. • Maintain adequate blood pressure during anesthesia. • Selective breeding

Complications

• Cardiac arrhythmias, congestive heart failure, pulmonary edema, uremic pneumonitis, or cardiopulmonary arrest • Gastrointestinal bleed • Hypovolemia, sepsis, and death • Seizures or coma

• • • • • • •

Prognosis

• Guarded to poor, but depends on severity and cause of disease

• Guarded to poor long term due to progression of disease

Urine Output • Anuria: ≤0.1 mL/kg/hr • Oliguria: ≤0.25 mL/kg/hr • Nonoliguria: ≥2 mL/kg/hr

• Approximately 75% of the kidney must be nonfunctional before an elevation in serum BUN and creatinine is seen.

6

Notes

Anemia Dehydration and constipation Gastroenteritis Hypertension Uremic stomatitis Urinary tract infection Weight loss

Table 6.53 / Urology: Urinary Tract Obstruction and Urinary Tract Infection Disease

Presentation

Definition

296

Urinary Tract Obstruction

Urinary Tract Infection (Cystitis, Urethrocystitis)

An obstruction restricting the flow of urine along the pathway from the kidneys to the external urethral orifice. The obstruction can be from blood clots, urethral plugs, uroliths, and sloughed tissue fragments.

Urinary tract infection is usually bacteria-induced inflammation of the lower urinary tract including the bladder and urethra. The cause is due to an ascending bacterial infection from the urethral orifice or hematogenous.

Clinical Signs

• Anorexia, crouching, depression, dysuria, hematuria, lethargy, pollakiuria, ↑ size and velocity of urine stream, stranguria, vomiting

• Dysuria, hematuria, malodorous, periuria, pollakiuria, stranguria, urinary incontinence

Examination Findings

• Abdominal pain, bradycardia, dehydration, distended urinary bladder, hypothermia, renomegaly

• Thickened, firm contracted bladder wall

SECTION THREE: DIAGNOSTIC SKILLS

Table 6.53 / Urology: Urinary Tract Obstructin and Urinary Tract Infection (Continued)

Follow-Up

Treatment

Diagnosis

Disease

Urinary Tract Obstruction

Urinary Tract Infection (Cystitis, Urethrocystitis)

General

• History/clinical signs • Abdominal palpation: kidneys and bladder

• History/clinical signs: recent catheterization or urinary tract surgery • Abdominal palpation: kidneys and bladder • Digital rectal examination: prostate in males

Laboratory

• • • •

Imaging

• Radiographs, abdominal: anatomic abnormalities, extended bladder, calculi, urethral plugs, tumors or urachal diverticula • Contrast: urethral strictures, tumors, radiolucent uroliths or vesicourachal diverticula • Ultrasound, abdominal: anatomic abnormalities, extended bladder, calculi, tumors, or urachal diverticula

• Radiographs, abdominal: anatomic abnormalities, calculi, tumors or urachal diverticula • Contrast: radiolucent calculi • Ultrasound, abdominal: anatomic abnormalities, calculi, tumors, or urachal diverticula

Procedures

• Cystoscopy • ECG: bradycardia, atrial standstill

• N/A

General

• • • •

• Symptomatic

Medication

• Antibiotics: variable • Calcium gluconate • Sodium bicarbonate

• Antibiotics: variable

Nursing Care

• Monitor bladder size and urine output.

• Treated as outpatient

Patient Care

• Monitor urine output and hydration status.

• Culture urine 1 week and 1 month after beginning treatment. • Allow frequent access to litter box or outdoors.

Prevention/ Avoidance

• Dependent on cause of obstruction

• Avoid glucocorticoid use or urethral catheterization.

Complications

• • • •

• Pyelonephritis • Cystic calculi • Recurrence

Prognosis

• Good with early detection and correction

CBC: ± stress leukogram Chemistry panel: ↑ phosphorus, potassium, ↓ calcium and azotemia Urinalysis: ↑ blood, protein, crystals Blood gases: metabolic acidosis

Fluid therapy Urohydropulsion Surgery: urethrotomy, urethrostomy Lithotripsy

Reobstruction UTI Urinary bladder rupture Urethral trauma during catheterization

• • • •

Chemistry panel: ↑ BUN, creatinine and azotemia Urinalysis: pyuria, ↑ blood, protein, bacteria, specific gravity Urine culture: bacteria isolation and identification Prostatic fluid analysis: bacteria and neutrophils

• Excellent

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6

Table 6.53 / Urology: Urinary Tract Obstructin and Urinary Tract Infection (Continued) Disease

Urinary Tract Obstruction

Urinary Tract Infection (Cystitis, Urethrocystitis)

Notes

• Caution: Due to the patient’s compromised state, chose anesthetics carefully. • Fluid therapy should not be started until obstruction is relieved.

Significant Bacteria Count Canine Cystocentesis: ≥1000 Catheter: ≥10,000 Voided: ≥100,000 Expressed: ≥100,000

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SECTION THREE: DIAGNOSTIC SKILLS

Feline ≥1000 ≥1000 ≥10,000 ≥10,000

Chapter

7

Emergency Medicine Emergency Medicine 301 Emergency Supplies 301 Telephone Assessment and Emergency Transportation Recommendations 304 Inducing Vomiting At-Home 305 Triage 306 Primary Survey 306 Hemostasis 307 Cardiopulmonary Cerebrovascular Resuscitation (CPCR) 308 Secondary Survey 309 Shock 310 Cardiac Emergencies 312 Environmental Emergencies 313

Gastrointestinal Emergencies 314 Hematologic Emergencies 315 Metabolic and Endocrine Emergencies 316 Neonatal Emergencies 317 Neonatal Resuscitation Post-Cesarean 317 Neurologic Emergencies 318 Ophthalmic Emergencies 319 Renal and Urinary Emergencies 320 Reproductive and Genital Emergencies 321 Respiratory Emergencies 322 Toxicologic Emergencies 323 Toxins 324 Trauma Emergencies 326

7

299

Key Words and Termsa Abducted Ambulation Anisocoria Ataxia Azotemia Cathartics Cyanosis Decerebellate posture Decerebrate resposne Dyschezia Dystocia Ecchymoses Edema Epistaxis Flail chest Hematemesis Hematochezia Hemoptysis Hyperemic Hyperesthesia Hyperreflexia Hyperthermia Hypertonia Icterus Incontinence Intraosseus Intussusception

7

a

Isoerythrolysis Lacrimation Lymphadenopathy Melena Mentation Micturition Mydriasis Nystagmus Oliguria Pallor Paradoxical respiration Paraphimosis Philtrum Pollakiuria Polydipsia Polyuria Ptyalism Pulse deficits Purulent Schiff-Sherrington’s posture Scleral injection Septicemia Strabismus Stranguria Triage

Key words and terms are defined in the glossary on page 631.

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SECTION THREE: DIAGNOSTIC SKILLS

Abbreviations

Additional Resources, page

ACT, activated clotting time ACTH, adrenocorticotropic hormone ANA, antinuclear antibody ASPCA, American Society for the Prevention of Cruelty to Animals BP, blood pressure BUN, blood urea nitrogen Ca2+, Calcium cm H2O, centimeters of water CNS, central nervous system CPCR, cardiopulmonary cerebrovascular resuscitation CRT, capillary refill time CT, computed tomography CVP, central venous pressure DOCP, desoxycorticosterone acetate ECG, electrocardiogram ET, endotracheal tube Fr, French GDV, gastric dilatation volvulus GIT, gastrointestinal tract GV, governing vessel H2O2, hydrogen peroxide HR, heart rate IV, intravenous kg, kilogram mg, milligram mm Hg, milliliters of mercury MM, mucous membranes MRI, magnetic resonance imaging NPO, nothing by mouth NSAIDs, nonsteroidal anti-inflammatory drugs PCV, packed cell volume pH, potential of hydrogen RR, respiratory rate Tb, tablespoon TP, total protein URI, upper respiratory infection UTI, urinary tract infection

Abdominocentesis, 429 Blood culture, 122 Blood gas analysis, 335 Blood pressure, 332 Blood transfusions, 367 Bone marrow evaluation, 83 Cardiopulmonary, 30 Central venous pressure, 334 Cesarean section, 542 Chest drain, 431 Coagulation tests, 115 Coupage, 432 CPCR, 308 Diagnostic peritoneal lavage, 429 Disinfectants, 627 Electrocardiogram, 338 Endoscopy, 551 Enema, 430 Fecal analysis, 134 Fine needle biopsy, 89 Fluid therapy, 359 Fluorescein sodium stain, 430 Gastric lavage, 428 Heat administration, 346 Laboratory, 71 Nebulization, 432

Neurologic examination, 34 Nutritional support, 413 Orthopedic examination, 36 Otoscopic examination, 33 Oxygen therapy, 375 Pain management, 379 Patient monitoring, 332 Pericardiocentesis, 431 Pharmacology, 567 Physical examination, 18 Pulse oximetry, 463 Radiology, 157 Recumbent patient care, 347 Shirmer tear test, 430 Stomach tube, 428 Surgery, 521 Thoracocentesis, 431 Tonometry, 430 Tracheostomy, 377 Ultrasound, 197 Urinalysis, 147 Urinary catheter maintenance, 436 Urinary catheter placement, 435 Urine collection, 434 Ventilator, 474 Vital signs, 19

Emergency Medicine Emergencies typically happen at the most inconvenient times. A well-stocked clinic and a staff trained in handling emergencies will make your team more efficient and each emergency therefore less stressful. Each member of the clinic should have a specific job during emergencies. Understanding the basics of what constitutes an emergency as well as being able to perform stabilizing and monitoring techniques is essential to assisting the veterinarian. This chapter covers the basic supplies, support, and monitoring techniques

necessary to handle an emergency. It also gives a very general coverage of emergencies by body system. All diagnoses and treatment prescriptions can be done only by the veterinarian. These tables are to assist the technician in monitoring the patient. The technician then will be able to alert the veterinarian of abnormalities and to carry out the veterinarian’s treatment therapy where applicable. Please note that this chapter is not meant to be “all inclusive,” and we urge each clinic to have a thorough emergency resource library in the clinic.

Table 7.1 / Emergency Supplies

Before any emergency patient arrives at the hospital, a crash cart should be assembled and diligently maintained to be available to assist the veterinarian and staff. Each clinic will have preferences regarding supplies and should set up their supplies to suit their needs. The items listed are examples of what may be needed and are not meant to be all inclusive. The most important part of the selected emergency supplies is familiarity. Each staff member must know his or her location and understand their use and operation. This knowledge will lead to a smooth recovery attempt.

7

Crash Cart • The items contained in the crash cart are the first items utilized in an emergency. These items should be dedicated to emergencies and are not used for daily purposes. One person should be designated to maintain the crash cart on a regular basis and to alert staff to any changes. Supplies • Stethoscope • IV catheters of various sizes, caps, T-ports, and tape • Syringes and needles (regular, spinal, intraosseus) of various sizes • Blood collection tubes

• Fluid delivery system (IV fluid bags and IV administration tubing) • Clippers and surgical scrub • Masks and gloves • Minor surgical instrument pack (scalpel handle, thumb forceps, needle holders, and 3 hemostats of various sizes)

• Scalpel blades • Suture material of various types • Endotracheal tubes of various sizes, laryngoscope, local anesthetic, ties, cuff syringe, and mouth gags • Urinary catheters for intratracheal injection

Equipment • Defibrillator

• Electrocardiograph

Drugs • • • •

Drug dose chart Atropine Ca2+ chloride or gluconate Dexamethasone sodium phosphate

• • • •

Dextrose Diazepam (if lock box available) Epinephrine Lidocaine 2%

• IV fluids (LRS, dextran 70, hypertonic saline, hetastarch) • Sodium bicarbonate • ± Phenobarbital (if lock box available)

Basic Equipment • These items provide basic support to the patient. These supplies may not necessarily be in the crash cart due to size and multiple hospital uses, but their location is known and easily accessible.

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Table 7.1 / Emergency Supplies (Continued) Supplies • • • •

Bandaging material Lubricating jelly Thermometer Heat support

• • • •

Blood pressure equipment Blood gas analyzer Pressurized fluid infusion cuff IV fluid warmer

• Oxygen delivery system (ambu bag, line to oxygen source, humidifier) • Pulse oximetry • Nebulizer

Specialized Equipment • These items are advanced equipment used in specific, critical situations. These items may not necessarily be in the crash cart due to size and multiple uses, but their location is known and easily accessible. • Respirator • Suction supplies (suction tubing, jar, pump)

• Tracheostomy pack • Thoracotomy pack

• Pericardiocentesis pack • Abdominocentesis pack

Drugs • This listing of drugs includes most of those used to treat critical patients. These drugs are typically kept in their regular location, the exception to the drugs listed in the crash cart. These drugs are used for treatment and not for immediate life-threatening situations.

7

Cardiac Drugs • Antiarrhythmics • Diltiazem, dexamethasone sodium phosphate, esmolol, lidocaine, procainamide, propranolol, verapamil • Diuretics • Furosemide • Inotropes • Digoxin, dobutamine, dopamine, isoprenaline, isoproterenol

• Vasodilators • Acepromazine, hydralazine, nitroglycerin ointment, nitroglycerin patch, captopril, diltiazem, sodium nitroprusside, amlodipine besylate, enalapril • Sedatives • Morphine, butorphanol, buprenorphine

• Other • Aspirin (antithrombotic therapy) • Ca2+ chloride (ventricular asystole) • Glycopyrrolate • Heparin (antithrombotic therapy) • Potassium chloride (chemical defibrillator)

• Bronchodilators • Cholinergic blockers, antihistamines, beta-2-adrenergic agonists (epinephrine, isoproterenol, albuterol), Methylxanthines (aminophylline)

• Stimulants • Doxapram hydrochloride, naloxone, yohimbine

• Antiulcer • H2-receptor antagonists (cimetidine, famotidine, ranitidine), antacids (magnesium hydroxide), gastromucosal protectants (sucralfate) • Misoprostol • Proton pump inhibitors (omeprazole) • Laxatives • Enemas, milk of magnesias, and glycerin

• Emetics • apomorphine, xylazine, ipecac syrup, hydrogen peroxide • Protectants/adsorbents • Bismuth subsalicylate, kaolin/pectin, activated charcoal

Respiratory Drugs • Antitussives • Butorphanol tartrate, hydrocodone bitartrate, codeine, dextromethorphan, Temaril-P Gastrointestinal Drugs • Antidiarrheals • Narcotic analgesics • Antiemetics • Chlorpromazine, prochlorperazine, anticholinergics, metoclopramide

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Table 7.1 / Emergency Supplies (Continued) Neurologic Drugs • Antiseizuring • Diazepam, phenobarbital

• Muscle relaxant • Methocarbamol

• Rapid-acting corticosteroids • Methylprednisolone sodium succinate

• Topical anesthetics • Proparacaine hydrochloride, tetracaine

• Stains • Fluorescein strips

• Ca2+ channel blockers • Diltiazem, verapamil • Diuretics • Furosemide, mannitol 20%, glucose

• Urinary alkalizers • Potassium citrate, sodium bicarbonate (oral) • Vasodilators • Hydralazine, dopamine, dobutamine

• R-insulin

• Percorten (DOCP)

• Pralidoxime (against organophosphates) • Fomepizole/Antizol-Vet (against ethylene glycol—dogs only)

• Hemostatic agent • Vitamin K1 • Antihistamine • Diphenhydramine

Ophthalmic Drugs • Reduces Intraocular pressure (IOP) • Carbonic anhydrase inhibitors, timolol maleate, mannitol, glycerol Renal/Urinary Drugs • ACE inhibitors • Captopril, enalapril • Antidiuretics • Vasopressin

7

Reproductive Drugs/Hormones • Oxytocin Toxicologic Drugs—Antidotes • Antidotes • Acetylcysteine (against acetaminophen) • Dimercaprol (against arsenical compounds) • Ethanol (against ethylene glycol)

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Table 7.2 / Telephone Assessment and Emergency Transportation Recommendations

When a client calls with an emergency situation, asking very specific questions and advising the owner on how to assess the situation, provide initial treatment, and move the animal are very important. Before beginning the assessment, inquire as to whether the owner and the animal are in a safe place. In any traumatic emergent situation, it is advisable to place a muzzle on the animal if no respiratory distress is noted and mucous membranes are pink. Recommendations listed below should be altered if the animal becomes aggressive or the procedure produces additional stress. Always ask the owner what is their expected arrival time. This will allow the staff to make any preparations necessary prior to their arrival. The goal of dealing with an emergency situation is to minimize stress of both the owner and the patient. Questions may need to be asked multiple times to maintain the attention of the upset and distracted owner. Regardless of the nature of the injury, if the owner perceives it as an emergency, it must be handled in that manner. On-Site Questions to the Client

Recommendations

What is the nature of the injury?

Have the owner give a quick assessment of the situation and the extent of the injuries. Based on this information, further questions can be asked.

Traumatic

7

• Hit by car, poisoning, seizures, drowning, fall, lacerations, fractures, and eye injuries • Is your animal awake or unconscious? • Does your animal respond to your commands?

• If the animal is unconscious, it needs to be rapidly assessed for breathing and circulation.

• Is your animal breathing? • Is your animal having trouble breathing?

• Animals in respiratory distress should have limited activity during transport and be allowed to maintain a position of comfort. • Animals not breathing should be given mouth-to-nose resuscitation and chest compressions during transport. Frequently, this will stimulate spontaneous breathing if initially caused by a vasovagal reflex. • See Skill Box 7.3 Cardiopulmonary Cerebrovascular Resuscitation (CPCR), page 308.

• What is the color of your animal’s mucous membranes?

• Compare the mucous membranes to your own—Are they more white, blue, or red? • If white or blue, assess for breathing and circulation. • Palpate the chest for a heartbeat or feel for a jugular pulse.

• Does your animal have external bleeding? • Is it pulsating?

• Apply direct pressure to the site of bleeding and elevate above the heart. • Leashes or ropes can be used as tourniquets placed proximal to the injury with arterial pulsating bleeding.

• Does your animal have a limb in an abnormal position? • Is he limping or not bearing any weight on the limb?

• Support fractures believed to be below the elbow or hock. • Secure the fractured limb with a roll of newspaper, magazine, board, or piece of cardboard with pieces of fabric or duct tape. • If this causes additional stress, gently transport the animal on thick fabric or a board (thin wood or cardboard).

Acute • GDV, poisoning, GIT obstruction, hives, vaccine reaction, respiratory complications • Is your animal having a seizure?

• If diabetic, administer Karo syrup orally. • Transport in a large towel for protection of the owner and animal; only loosely cover the animal during transport to avoid hyperthermia.

• Does your animal have a distended abdomen?

• Avoid pressure on the abdomen. • Do not allow the animal to eat or drink in transport. • If nonambulatory, transport on thick fabric or a board (thin wood or cardboard).

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SECTION THREE: DIAGNOSTIC SKILLS

Table 7.2 / Telephone Assessment and Emergency Transportation Recommendations (Continued) • Has your animal eaten something poisonous? If so, when?

• Remove the animal from the toxin. • Bring any remaining substance and/or packaging, vomit, or feces. • If no other symptoms are present, call Poison Control Center and possibly induce vomiting (e.g., hydrogen peroxide). • See Skill Box 7.1, page 305 and Chapter 17 Pharmacology, page 593.

• Is your animal vomiting or have diarrhea?

• Bring in samples.

• Is your animal gagging/retching?

• Try to comfort the animal to decrease these symptoms.

• Is your animal choking?

• If possible, observe the inside of the mouth for an obstruction to be removed. • Administer a sharp blow with the palm of your hand between the shoulder blades. • Perform a modified Heimlich procedure—With the animal beside you and head forward, place arms around abdomen with fist just behind the ribs, compress the abdomen 3–5 times with quick inward-up pushes, check the mouth for the foreign body, and repeat 1–2 more times if necessary.

Chronic • UTI, kennel cough, URI

7

• What is your animal’s ability to urinate?

• Avoid pressure on the abdomen.

• Is your animal coughing?

• Once arriving at the clinic, leave your animal in the car while checking in.

• Is your animal in labor?

• Place the delivered neonates in a box with heat support (warm water bottles or heating pad wrapped in a towel). • Gently transport the female as she may be quite uncomfortable.

Skill Box 7.1 / Inducing Vomiting At-Home Inducing vomiting is a very common treatment for a foreign body or toxic ingestions. However, care must be taken before giving this advice or performing the procedure as it can be more dangerous to bring the item back up versus letting the animal digest or pass the item. For example, alkalis, acids, corrosive agents, petroleum products, or hydrocarbons should not be expelled, and animals with preexisting conditions such as epilepsy, cardiovascular disease, debilitated, or recent abdominal surgery or those with a potential for gastric torsion should avoid induced vomiting. One of the best resources for accurate information is the Poison Control Center (800-222-1222) or the ASPCA Poison Control Center (888-426-4435 with a possible consultation fee). Vomiting at-home is best performed using hydrogen peroxide (H2O2) within 2–3 hours postingestion with expectation of getting 40–60% of the stomach contents expelled. Three percent H2O2 produces mild gastric irritation leading to vomiting. Higher strengths or overdosing will lead to severe gastritis, especially in cats. If no vomiting occurs after the second

dose, the animal should be brought in for administration of apomorphine and/or other treatments. H2O2 Dose 1 mL (1 tsp) per lb. to a maximum dose of 45 mL (3 Tb) This dose may be repeated 1 time in 10 minutes. Tips for a Successful At-Home Procedure 1. Verify the H2O2 is a 3% strength. 2. Verify the H2O2 has not expired. 3. Feed a small meal, e.g., 1–2 pieces of bread. 4. Administer the H2O2. a. Mix with equal parts of milk or ice cream (1 Tb. H2O2 + 1 Tb. milk). b. Use a liquid medicine syringe, sports squirt bottle, or turkey baster. 5. Exercise the animal (e.g., playing fetch, quick walk). CHAPTER 7 / EMERGENCY MEDICINE

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Triage When presented with an animal suffering a life-threatening problem, a successful outcome requires hospital readiness, effective teamwork, practiced triage skills, and a rapid response to primary survey abnormalities. “Triage” is the process of giving priority to those patients with the most critical problems. This begins with the assessment of the 3 major body systems: respiratory, cardiovascular, and neurologic. This quick primary survey will allow the best approach to treatment to be continued during the secondary survey. The primary survey is a brief physical examination. Many details are ascertained simultaneously to obtain the information quicker. Even though obvious injuries can be alarming, the patient must have a stable cardiovas-

cular and respiratory system before other injuries are addressed. Begin the assessment as you approach the animal, evaluating the presenting clinical signs. Next, address any arterial vessel injury. Respirations can then be appreciated with auscultation while also evaluating the heart. If no respirations are heard, oxygen supplementation via ET tube or tracheostomy should be done. The heart should have clear decisive sounds heard from either side and should be evaluated in conjunction with the peripheral pulse. The patient’s capillary refill time, mucous membrane color, and body temperature should also be evaluated. Any alterations should be addressed (e.g., CPCR, drug administration, debrillator, etc.) to stabilize the patient. The central nervous system should also be evaluated through pupillary response and position, reflexes, and presenting clinical signs.

Table 7.3 / Primary Survey

7

Presenting Clinical Signs

Physical Examination

Causes

Immediate Action

• No passage of air • Loud inspiratory or expiratory sounds • Altered breathing patterns • ↑ Respiratory effort, dyspnea • Change in mucous membrane color

• • • • • • • •

Respiratory distress Complete or partial obstruction Upper airway trauma or rupture Pneumothorax Hemothorax Pulmonary contusions Diaphragmatic hernia Flail chest

• Oxygen therapy • Intubate orally or by slash tracheostomy • Remove foreign object manually or by a modified-Heimlich maneuver • CPCR

• Change in mucous membrane color and moisture • Delayed capillary refill time • Pulse presence and intensity • Heart rate and rhythm • Hyper- or hypothermia • Cold extremities • Crackles in lung fields on auscultation

• • • • •

Arterial or venous injury Heart failure Thromboembolism Pleural effusion Pulmonary edema

• • • • •

Respiratory • • • • • •

Panting (feline) Paradoxical respiration Open mouth breathing Coughing ↑ or ↓ Respiratory rates Extended head or neck with abducted elbows • Nasal flare Cardiovascular • • • • •

External hemorrhage Panting Weakness, collapse Abdominal distention Cough, exacerbated with activity or exercise

306

SECTION THREE: DIAGNOSTIC SKILLS

Hemostasis Oxygen therapy CPCR Thoracocentesis/pericardiocentesis ECG monitoring

Table 7.3 / Primary Survey (Continued) Presenting Clinical Signs

Physical Examination

Causes

Immediate Action

• Pupillary response, size, and position • Eye position: strabismus, nystagmus • Motor reflexes • Pain response • Hyperthermia • Hypertonia • Hyperflexia

• • • • • •

• Oxygen therapy • Anticonvulsants

• Changes in conformation, limb angles • Pain response • Bleeding soft tissue wounds

• Trauma

Central Nervous System • • • •

Level of consciousness Head position Seizuring Ambulation • Severe front end rigidity and hindend weakness: Shiff-Sherrington Syndrome • Generalized weakness/paresis

Heat trauma Intoxication Spinal cord injury Seizures Infections; bacterial, parasitic Vestibular syndrome

Body Condition • • • • •

Lacerations Fractures/malalignments Eye injuries Abdominal distention Burns

• Oxygen therapy • Analgesics • Wound care: keep moist with a sterile water soluble lubricant and sterile dressing • Fractures: clip, examined, stabilize

Skill Box 7.2 / Hemostasis Controlling hemorrhage can be a first-line defense against shock, allowing the patient to maintain an adequate volume of blood. Initially, direct digital pressure can be placed to provide hemostasis. This can be direct pressure over the injury (or if an extremity or tail) by encircling the area proximal to the injury and applying pressure. Sterile dressings should always be used to avoid contamination of the wound. Pressure wraps can be placed for hemostasis. If the wrap becomes soaked, another wrap

should be placed on top of the first. Tourniquets should be avoided as they can cause tissue and nerve damage within minutes. With arterial hemorrhage, the artery should be clamped and ligated when possible. If that is not possible, direct pressure should be placed on a pressure point following one of the techniques below dependent on which artery is compromised.

Area of Hemorrhage

Pressure Point

Area of Hemorrhage

Pressure Point

• Maxillary artery

• Deep area adjacent and ventral to the mandible

• Inguinal artery

• Caudal abdomen

• Brachial artery

• Axillary area

• Distal extremity artery

• BP cuff placed proximal to the injury with a pressure of 200 mm Hg

• Femoral artery

• Inguinal and femoral canal region

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7

Skill Box 7.3 / Cardiopulmonary Cerebrovascular Resuscitation (CPCR) CPCR should ideally be conducted on an adjustable height solid table. Depending on the size of the animal and staff, it may be necessary to provide a stool or perform the procedure on the floor. A surgical grated prep table should not be used for CPCR as it does not provide the counterpressure needed for chest and abdominal compressions. The steps below should be assigned to various team members so that the animal’s resuscitation is conducted as smoothly and thoroughly as possible.

7

A. Airway Alert the emergency team of upcoming arrival of patient. Assess the airway. • Extend the patient’s head and neck and pull tongue forward; remove any debris manually or with suction. • Establish a patent airway with endotracheal intubation or a slash tracheostomy. B. Breathing Assess breathing. • Confirm apnea. • Provide mechanical ventilation via an Ambu bag or anesthetic machine with 100% oxygen at a rate of 150 mL/kg/min. • Initiate with 2 breaths for 2 seconds each. • Reassess for spontaneous respiration. • If none, continue at 12–20 breaths/min (1 breath/3–5 seconds) and attempt acupuncture to stimulate respiration. (Place a 25-gauge needle into the midline just below the nose [philtrum] at acupuncture point governing vessel [GV] 26. Penetrate the skin and subcutaneous tissue from 2 to 4 mm. Rotate the needle up and down at this point to stimulate the site.) • Each breath should have an expiration slightly longer than inspiration and a manometer pressure reading of: • Canine pressure: ≤20 cm H2O • Feline pressure: ≤15 cm H2O C. Circulation Assess circulatory function. • Confirm absence of heart beat and peripheral pulses. • External cardiac compression • Provides ∼30% of normal cardiac output • Check for femoral or carotid artery pulse repeatedly throughout this process. • Animal weighing <7 kg: lay in right lateral recumbency and start compressions with 1 or 2 hands over the 3–5 intercostal space. • Animal weighing >7 kg: lay in right lateral or dorsal recumbency and start compressions with the palm of the hands over the distal 1/3 of the rib cage. • Use enough force to displace the thorax 30%. • Respirations are given with every or every other compression. • Abdominal compressions are given between chest compressions. • One person: 5 compressions, then 1 ventilation. • Two people: 1 compression, then 1 ventilation. • Three people: 1 compression, 1 ventilation, then 1 abdominal compression. • Internal cardiac compression • Provides 60–90% more effective cerebral and coronary perfusion • Preferred method with rib fractures, pleural effusion, pneumothorax, cardiac tamponade, diaphragmatic hernia, flail chest • Initiated after 5 minutes if effective tissue perfusion is not seen 308

SECTION THREE: DIAGNOSTIC SKILLS

Skill Box 7.3 / Cardiopulmonary Cerebrovascular Resuscitation (CPCR) (Continued) • Initiated after 10 minutes is spontaneous rhythm has not returned • Place in left lateral recumbency and a thoracotomy is performed at the 5th–6th intercostal space. • The palm and fingers are used to pump the heart in a rhythmic fashion. D. Drugs (atropine, epinephrine, lidocaine, naloxone, magnesium chloride) E. Evaluation of the patient with a thorough examination ECG F. Fibrillation Control Fluids

Table 7.4 / Secondary Survey

After the primary survey, the patient is classified as stable, potentially unstable, or unstable. Following this determination, resuscitation of vital functions and stabilization of life-threatening problems takes place. Once stable, a thorough past and current medical history, physical examination, and laboratory database are obtained. This is followed by reassessment of the original treatments. Secondary Survey

History and Procedures

Past Medical History

• • • • •

Medical conditions Drug therapies Allergies Vaccination history Previous transfusions

Current Medical History

• • • • • • • • • •

Presenting complaint When animal was last normal Chronology and progression of signs Potential toxin ingestion Physical trauma Signs of collapse, weakness or ↓ ability to exercise Signs of abnormal neurologic behavior Travel history Access to other animals Affinity to eat abnormal things

Physical Examination

• Vital signs • Evaluation of organ systems not involved • See Chapter 2 Physical Examination, page 18.

Stat Lab Database

• • • •

PCV, TP Chemistry panel and electrolytes Complete blood count Urinalysis

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7

Table 7.5 / Shock

Shock is typically the result of poor oxygen delivery. The goal, regardless of form, is to optimize oxygen delivery. The most effective way to improve oxygen delivery is to ↑ cardiac output by optimizing preload with fluid administration. Cardiogenic Shock

Septic Shock

Definition

Diminished blood volume leading to tissue perfusion failure.

Tissue perfusion failure due to inadequate cardiac output

Circulatory disorder due to bacteria or bacterial endotoxin release

Cause

Hemorrhage, fluid loss (e.g., burns, vomiting, diarrhea, ↑ urine production), poor venous return (e.g., GDV), severe GIT bleed, severe epistaxis, addisonian crisis (e.g., hypotension)

Cardiomyopathy, cardiac tamponade, cardiac arrhythmias, heartworm disease, pulmonary hypertension, pulmonary thromboembolism, pericardial disease, heart failure, valvular disease with decompensation

GIT compromise/rupture, urinary tract infection (UTI), septic peritonitis, pneumonia, bacterial endocarditis, bite wounds, myelosuppression, prostatitis

Presenting Clinical Signs

• Muscle weakness, mental depression

• Muscle weakness or collapse, mental depression, cough, labored breathing

• Extreme weakness, mental depression

Primary Survey Findings

Compensatory stage: bounding pulses, cool extremities, pale or hyperemic mucous membranes, hypertension, delayed CRT, tachycardia, tachypnea Decompensatory stage: hypotension, hypothermia, ↓ mental status, oliguria, pale or muddy mucous membranes, delayed CRT, poor peripheral pulses, tachycardia or bradycardia

Abnormal heart sounds (e.g., gallop, murmur), arrhythymias, cardiac tamponade (tachycardia, weak pulses, hepatomegaly, jugular distention), cool extremities or hypothermia, dyspnea or tachypnea, harsh lung sounds or crackles, pale or cyanotic mucous membranes, prolonged CRT, variable HR and RR, weak femoral pulses and pulse deficits

Compensatory stage: bounding pulses, dyspnea or tachypnea, hyperemic mucous membranes, hypertension, mental depression, pyrexia, rapid CRT (<1 second), tachycardia, weakness Decompensatory stage: cool extremities, GIT bleeding (hematemesis, hematochezia), pale mucous membranes and delayed CRT, peripheral edema, petechiation, poor peripheral pulses, tachycardia or bradycardia, tachypnea

Equipment

• Crash cart • Basic emergency equipment • Specialized emergency equipment

• Crash cart • Basic emergency equipment • Specialized emergency equipment

• Crash cart • Basic emergency equipment • Specialized emergency equipment

Medication

• • • • •

• • • •

• • • • • •

Presentation

Hypovolemic Shock

Preparation

7

Emergent Condition

310

Blood plasma transfusions Positive inotropes Steroid therapy (short-acting) Vasopressor agents IV crystalloids/colloids

SECTION THREE: DIAGNOSTIC SKILLS

Antiarrhythmics Diuretics Positive inotropes Vasodilators

Antibiotics Blood/plasma transfusions Positive inotropes Sodium bicarbonate Steroids Vasopressor agents

Table 7.5 / Shock (Continued) Emergent Condition

Diagnostics / Treatments

Procedures

Patient Care

Monitoring

Hypovolemic Shock

Cardiogenic Shock

Septic Shock

• • • • • •

• • • •

• • • • • •

BP CVP ECG Endoscopy Hemostasis Imaging: • Thoracic radiographs • ± Abdominal radiographs • Ultrasonagraphy • Lab tests: • ACT • Blood gas analysis • Coagulation profile • Stat lab database • Oxygen therapy • Thoraco- or abdominocentesis

• General: general behavior, muscle strength, body temperature • Respiratory: RR and effort, lung sounds, tidal volume, respiratory pattern, SpO2 • Cardiovascular: HR and rhythm, BP, mucous membranes, CRT, ECG, CVP • Renal: urine output • Lab tests: PCV, TP, electrolytes, BUN, creatinine, liver enzymes, blood gas analysis, lactate

• • • •

BP CVP ECG Imaging: • Thoracic radiographs • Echocardiography Lab tests: • Blood gas analysis • Stat lab database Oxygen therapy Pericardiocentesis Pulse oximetry

•

• • • • General: general behavior, muscle strength, body temperature • Respiratory: RR and effort, lung sounds • Cardiovascular: HR and rhythm, BP, mucous membranes, CRT, ECG, CVP, SpO2 • Renal: urine output • Lab tests: PCV, TP, electrolytes, BUN, creatinine, liver enzymes, blood gas analysis

Abdominocentesis, arthrocentesis BP CVP ECG Endoscopy Imaging: • Thoracic radiographs • Echocardiography • Ultrasonagraphy Lab tests: • ACT • Blood cultures • Blood gas analysis • Coagulation profile • Stat lab database Oxygen therapy Surgery Wound care

7

• General: general behavior, muscle strength, body temperature • Respiratory: RR and effort, lung sounds • Cardiovascular: HR and rhythm, BP, mucous membranes, CRT, CVP, ECG, SpO2 • Renal: urine output • Lab tests: PCV, TP, electrolytes, BUN, creatinine, liver enzymes, blood gas analysis

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Table 7.6 / Cardiovascular Emergencies

Diagnostics / Treatments Patient Care

7

Preparation

Presentation

Emergent Condition

312

• Atrial or ventricular septal defect, cardiac arrest, cardiac arrhythmias, cardiac tear, cardiomyopathy, caval syndrome, congestive heart failure, heartworm disease, hypertension, infective endocarditis, left- and/or right-sided heart failure, patent ductus arteriosus, pleural effusion, pulmonary edema, pulmonic or aortic stenosis, severe ascites, subvalvular aortic stenosis, tetrology of Fallot, thromboembolism, tricuspid dysplasia, valvular, tamponade, or pericardial disease

Presenting Clinical Signs

• Abdominal distention, anxiety, depression, exercise intolerance, head extended ± hemoptysis, lethargy, acute blindness, resistance to restraint/movement, sudden lameness, syncope, weakness/collapse, abdominal respiration, dyspnea ± cough or muffled sounds, open-mouth breathing, tachypnea

Primary Survey Findings

• Abdominal swelling, ascites, cold extremities, mydriasis, weakness, dull heart sounds, harsh lung sounds, delayed CRT, dysrhythmias, jugular vein distention, murmurs, pale or cyanotic mucous membranes, tachycardia with weak or bounding pulses, hepatomegaly, dehydration, hypotension, oliguria

Equipment

• Basic crash cart equipment • Specialized crash cart equipment • Radiography

Medication

• • • •

Procedures

• • • • •

Bilateral thoracocentesis or pericardiocentesis (with ECG monitoring) CVP Pulse oximetry ECG Lab tests: • Stat lab database • Arterial blood gas analysis • Blood culture (pericardial fluid) • Imaging: • Thoracic radiographs • Oxygen therapy and positive pressure ventilation

Monitoring

• General: Body temperature, body weight, pain management, minimal patient handling, calm and quiet environment, support in sternal position to elevate the head and neck to facilitate cerebral blood flow, heat support and warming of extremities • Respiratory: RR and effort, lungs sounds • Cardiovascular: HR and rhythm, pulse rate and quality, femoral pulses (feline), BP, mucous membranes, CRT, ECG, CVP, thoracic radiographs • Renal: Urine output, hydration • Lab tests: Electrolytes, BUN, creatinine, blood gas analysis

SECTION THREE: DIAGNOSTIC SKILLS

β-Blockers Diuretics Sodium influx inhibitors Positive inotropes

• Tranquilization • Vasodilators • Sympathomimetics

Table 7.7 / Environmental Emergencies

Patient Care

Diagnostics / Treatment

Preparation

Presentation

Emergent Condition

• Drowning, electrocution, frostbite, heatstroke, hypothermia

Presenting Clinical Signs

• Ataxia, burns, collapse, diarrhea, epistaxis, hematemesis, hematochezia, hemoptysis, hypersalivation, listlessness, loss of consciousness, muscle tremors, shivering, vomiting, dyspnea, moist cough, panting, seizures

Primary Survey Findings

• Hyper- or hypothermia, hypotension, localized swelling, oral sensitivity, petechiation, tissue necrosis, pulmonary edema, respiratory arrest, cardiac arrthythmias, pale or cyanotic mucous membranes, tachy- or bradycardia, weak or hyperdynamic pulses

Equipment

• Basic crash cart equipment • Radiography

Medication

• • • • • •

Procedures

• ECG • Imaging: • Thoracic radiographs • Lab tests: • Stat lab database • Coagulation profiles • Blood gas analysis • Intubation and positive end-expiratory pressure • Oxygen therapy • Temperature control

Monitoring

• • • • •

Antibiotics Anticonvulsants Bronchodilators Diuretics Gastric protectants Steroids

7

General: Pain management, nutritional support Respiratory: RR and effort Cardiovascular: HR and rhythm, BP, ECG Renal: Urine output Lab tests: Blood gas analysis

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Table 7.8 / Gastrointestinal Emergencies

Preparation

Presentation

Emergent Condition

Presenting Clinical Signs

• Abdominal distention/pain, anxiety, diarrhea, dyschezia, hematochezia, hypersalivation, lethargy, melena, nonproductive retching, pawing at mouth, polydipsia, restlessness, vomiting (hematemesis)

Primary Survey Findings

• Cyanosis, distended abdominal veins, ecchymoses, halitosis, hyperthermia, periumbilical hemorrhage, petechiation, ↓ femoral pulses, weak or rapid pulse, ↓ CRT, dehydration

Equipment

• • • •

Basic crash cart equipment Endoscopy Radiography Ultrasonography

Medication

• • • • •

Analgesics Antacids Antibiotics Antidiarrheal Antiemetics

Procedures

• Abdominocentesis, ± diagnostic peritoneal lavage • CVP • Lab tests: • Stat lab database • ACT • Coagulation profile • Fecal analysis (direct, flotation, parvovirus test) • Urinalysis • Imaging: • Abdominal radiographs, ± contrast studies • Utrasonograph • Endoscopy (foreign body retrieval) • Laparotomy

Monitoring

• General: Pain management, NPO for hours to days with gradual introduction of a bland diet, turn recumbent patients every 2–4 hours, neck should be kept slightly elevated if concern of regurgitation or aspiration • Respiratory: RR and effort • Cardiovascular: HR and rhythm, pulse rate and strength, BP, mucous membranes, CRT, ECG, CVP • Gastrointestinal: Inappetence, defecation, vomiting • Renal: Urine output, hydration • Lab tests: PCV, TP, electrolytes, BUN, amylase, lipase, blood glucose, albumin, white blood cell count

Patient Care

Diagnostics / Treatment

7

314

• Acute gastritis, acute hepatic failure, acute intussusception, acute pancreatitis, bowel perforation, colitis, constipation, alimentary foreign bodies/obstructions, GDV, hemorrhagic gastroenteritis, parasitic infections, poisons, rectal prolapse, gastroduodenal ulcer disease

SECTION THREE: DIAGNOSTIC SKILLS

• • • • •

Dextrose Gastric protectants Motility modifiers Plasma therapy Sedation

Table 7.9 / Hematologic Emergencies

Patient Care

• Anemia, hemorrhage, immune-mediated thrombocytopenia, coagulopathies

Presenting Clinical Signs

• Anorexia, collapse, epistaxis, exercise intolerance, fleas/ticks, hematochezia, bruising, hematoma, hemoptysis, hemorrhage, lethargy, melena, muscle wasting, pica, syncope, weakness, weight loss, hematuria

Primary Survey Findings

• Ecchymoses, gingival bleeding, hypothermia, icterus, joint pain or swelling, lymphadenopathy, organomegaly, pallor, petechiation, dyspnea, murmurs, tachycardia, weak/thready or pounding pulses

Equipment

• • • •

Basic crash cart equipment Specialized crash cart equipment Radiography Utrasonograph

Medication

• • • • • • • • •

Anticoagulants Antiparasiticidals Blood products Chemotherapy agents Gastric protectants H2-blockers Proton pump inhibitors Steroids Vitamin K

Procedures

• BP • Bone marrow biopsy • Imaging: • Thoracic and abdominal radiographs • Ultrasonography • Lab tests: • Stat lab database • Reticulocyte count • Bone marrow evaluation • Coombs’ test • Coagulation profile • Fecal analysis • Bleeding time tests • ANA titer • von Willebrand test • Oxygen therapy

Monitoring

• • • •

Diagnostics / Treatment

Preparation

Presentation

Emergent Condition

7

General: Body temperature Respiratory: RR and effort, lung sounds Cardiovascular: HR and rhythm, BP, CVP, SpO2 Lab tests: PCV, TP, urinalysis, ACT

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Table 7.10 / Metabolic and Endocrine Emergencies

Treatment

316

• Diabetes mellitus, diabetic ketoacidosis, hyper- or hypocalcemia, hyper- or hypokalemia, hyper- or hyponatremia, hypoadrenocorticism (Addison’s), hypoglycemia, hypoproteinemia, metabolic acidosis, metabolic alkalosis, thyrotoxicosis

Presenting Clinical Signs

• Anorexia, ataxia, coma, diarrhea, dry and flaky skin, hypersalivation, Kussmaul breathing, lethargy, muscle tremors, panting, plantigrade stance, polydipsia, polyphagia, polyuria, restlessness, seizures, vomiting, weakness, weight loss

Primary Survey Findings

• Blindness, epigastric pain, hyper- or hypothermic, ketotic breath, muscle wasting, severe depression, weight loss, dehydration, hypotension

Equipment

• Basic crash cart equipment • Blood glucose monitor • Electrolyte analyzer (e.g., VetTest, I-stat)

Medication

• • • • • •

Procedures

• Lab tests • Stat lab database • ACTH stimulation test • ECG

Monitoring

• • • • •

Patient Care

7

Preparation

Presentation

Emergent Condition

SECTION THREE: DIAGNOSTIC SKILLS

Antiemetic Anti-inflammatory Bone resorption inhibitors Dextrose Diuretics Fluid therapy (± sodium bicarbonate, dextrose, or electrolytes)

• Insulin therapy (insulin adheres to plastic, flush tubing with 30–50 mL of insulin before beginning treatment) • Mineralocorticoids (e.g., Florinef, Percorten-V) • Supplements • Ca2+ • Phosphorous • Potassium

General: Mental and neurological status, body temperature, body weight, pain management Respiratory: RR and effort, lung sounds Cardiovascular: Pulse, ECG Renal: Urine output Lab tests: PCV, TP, electrolytes, BUN, creatinine, blood glucose, Ca2+, phosphorous, blood gas analysis, urinalysis

Table 7.11 / Neonatal Emergencies

Patient Care

Treatment

Preparation

Presentation

Emergent Condition

• Conjunctivitis, dehydration, severe dermatitis, dysphagia, hypoglycemia, hypothermia, hypoxia, infectious diseases, intussusception, juvenile cellulitis, neonatal isoerythrolysis, heavy parasitic load, septicemia, umbilical infection

Presenting Clinical Signs

• Anorexia, bloating, crying, depression, diarrhea, edematous rectum, facial swelling, fever, lethargy, limp, poor muscle tone, relaxed, tremors, unthriftiness, vomiting, weight loss, seizures

Primary Survey Findings

• Coma, deep pyoderma, GIT paralysis, hypothermia, lymphadenopathy, pale, gray or cyanotic mucous membranes, palpable intussusception, poor bowel sounds, ↓ respirations, tachy- or bradycardia, dehydration

Equipment

• Basic crash cart equipment • Warming cage or unit

Medication

• • • • • •

Antibiotics Blood transfusion Dextrose Respiratory stimulants Steroids Vitamin K

7

Procedures

• Lab tests: • Stat lab database • Blood glucose • Fecal analysis (direct, flotation, parvovirus test) • Bacterial culture samples (whole blood, urine, feces, exudate) • Oxygen therapy

Monitoring

• General: Mentation, body temperature, body weight, heat support (gradual warming over 30–60 minutes), turn every hour, nutritional support • Respiratory: RR and effort, lung sounds • Cardiovascular: HR and rhythm, mucous membranes, CRT • Renal: urine output, hydration • Lab tests: PCV, TP, blood glucose

Skill Box 7.4 / Neonatal Resuscitation Post-Cesarean There are many methods that can be used to stimulate a neonate to begin spontaneous respirations. A delivered neonate should be immediately placed in a dry towel with an assistant. The neonate is dried off by rubbing vigorously with the towel to lessen the chances of hypothermia and to stimulate respirations. The neonate should be examined for any obstructive secretions or fluid obstructing the airway. If spontaneous respirations do not begin, the assistant may employ 1 or more of the following techniques: • While supporting the head and neck to avoid whiplash or concussive injury, swing the neonate in a large downward arc to clear fluid in the chest via centrifugal forces and gravity.

• Place 1–2 drops of doxapram hydrochloride sublingually. • Use the acupuncture point governing vessel (GV) 26. Hold the neonate with its head elevated above its heart and its neck extended, and place a 25-gauge needle into the midline just below the nose (philtrum). Penetrate the skin and subcutaneous tissue 2–4 mm, and stimulate the site by rotating the needle up and down. • Provide artificial respiration by placing a 20-gauge catheter endotracheally or by blowing gently into the nose and mouth (normal, 15–40 breaths/ min).

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Table 7.12 / Neurologic Emergencies

Preparation

Presentation

Emergent Condition Presenting Clinical Signs

• Aggression, agitation, ataxia, blindness, circling, coma, depression, disorientation, epistaxis, head tilt, head tremors, leaning, loss of balance/coordination, loss of motor ability, mastication, nystagmus, paralysis, paresis, salivation, stupor, vomiting, hyperventilation, seizures

Primary Survey Findings

• ↓ Facial sensation, anisocoria, anorexia, ataxia, Horner’s syndrome, hyperreflexia, hyperthermia, hypertonia, otitis media/ interna, pain, paresis, reflex deficiencies, Cheyne-Stokes respiration, decerebellate rigidity, decerebrate rigidity, SchiffSherrington’s posture

Equipment

• Basic crash cart equipment

Medication

• • • •

Procedures

• BP • Lab tests: • Stat lab database • Blood gas analysis • Lead levels • Serology for infectious diseases • Ear cytology • Myelography, spinal tap, MRI • Otoscopic examination • Oxygen therapy

Monitoring

• General: Mentation, body temperature, pain management, elevate the front end 20–30° to ↑ cerebral venous drainage and avoid pressure on the neck • Respiratory: RR and effort, respiratory pattern, SpO2 • Cardiovascular: HR and rhythm, pulse rate and quality, BP • Neurologic: Pupil size and response, motor activity, deep pain assessment, posture, vision • Lab tests: PCV, TP, blood glucose, blood gas analysis

Patient Care

Treatment

7

318

• Bacterial infections, cancer/tumors, comas, head injuries, metabolic imbalances with secondary CNS changes, parasitic infestations, seizures, spinal cord injuries, toxins, vestibular syndrome

SECTION THREE: DIAGNOSTIC SKILLS

Anticonvulsants Antibiotics Diuretics Steroids

Table 7.13 / Ophthalmic Emergencies • Bite wounds/scratches, chemical burns, corneal laceration/abrasion/perforation/ulcer, descemetocele, severe ectropion, enophthalmos, severe entropion, foreign bodies, glaucoma, hyphema, keratoconjunctivitis sicca, lens luxation, orbital cellulitis, panophthalmitis, proptosed globe, retrobulbar mass, symblepharon, uveitis • Blindness, corneal color change, discharge, pain, pawing or rubbing the eye, photophobia, running into objects, squinting

Primary Survey Findings

• ↑ or ↓ intraocular pressure, absent papillary light reflex, aqueous flare, blepharospasm, bulb protusion, corneal edema, dilated pupil, inability to blink, inability to retract eye, lacrimation, loss of visual acuity, miotic pupil, negative menace response

Equipment

• • • • •

Black light Fluorescein strips Ophthalmoscope Schirmer tear test strips Tonometer

Medication

• • • • • • •

Antiglaucomas Diuretics Miotics Mydriatics Steroids Topical anesthetics Topical antibiotics

Diagnostics / Treatment

Presenting Clinical Signs

Procedures

• Imaging: • Skull radiographs • CT Scan • Lab tests: • Stat lab database • Ophthalmic examination: • Tonometer • Schirmer tear test • Fluorescein stain • Surgery

Patient Care

Preparation

Presentation

Emergent Condition

Monitoring

• General: Elizabethan collar, pain management • Ophthalmic: discharge, worsening of previous clinical signs

7

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Table 7.14 / Renal and Urinary Emergencies

Preparation

Presentation

Emergent Condition Presenting Clinical Signs

• Anorexia, ataxia, crying, depression, dysuria, lethargy, vomiting, pollakiuria, polydipsia, polyuria, stranguria, seizures

Primary Survey Findings

• Distended and/or painful abdomen, halitosis, hyper- or hypothermia, oral ulcerations, scleral injection, tachypnea, bradycardia, pale mucous membranes, anuria, dehydration, distended bladder, hematuria, large painful firm kidneys, polydipsia, polyuria

Equipment

• • • • •

Basic crash cart equipment Radiology Ultrasonography Urinary catheters; variety of types (rigid, Foley, feeding tubes) and sizes (3.5–14 Fr) Closed urinary collection system

Medication

• • • • • •

Antibiotics Antiemetics Diuretics Metabolic disorder drugs (e.g., Ca2+, dextrose, insulin) Gastric protectants Sodium bicarbonate

Procedures

• • • • •

Monitoring

• • • • •

Patient Care

Treatment

7

320

• Acute or chronic late-stage renal failure, azotemia, bacterial infection, bladder/ureter/urethra ruptures, feline lower urinary tract disease, pyelonephritis, severe cystitis, toxins, urinary obstructions, uroliths

SECTION THREE: DIAGNOSTIC SKILLS

BP CVP Cystocentesis ECG Imaging: • Abdominal radiographs • Ultrasonography • Lab tests: • Stat lab database • Urine culture • Ethylene glycol testing • Leptospirosis titers • Surgery • Urethral catheterization, normograde, retrograde, hydropropulsion General: Elizabethan collar, body weight, pain management, nutritional support Respiratory: RR and effort, lung sounds Cardiovascular: HR and rhythm Renal: Urine output, hydration, pH, specific gravity Lab tests: PCV, TP, electrolytes, BUN, creatinine, Ca2+, phosphorus, blood glucose, blood gas analysis

Table 7.15 / Reproductive and Genital Emergencies

Patient Care

• Male: Acute prostatitis, acute scrotal dermatitis, fractures of the os penis, infectious orchitis, laceration of the penis, paraphimosis, scrotal neoplasia, testicular torsion, • Female: Acute metritis, dystocia, eclampsia, pyometra, septic mastitis, uterine prolapse/torsion/rupture, vaginal prolapse/neoplasia

Presenting Clinical Signs

• Male: Depression, difficulty urinating/defecating, licking genital area, pain, purulent or bloody discharge from the urethra, vomiting, walking difficulties • Female: Depression, pain, panting, restlessness, salivation, vomiting, walking difficulties, licking genital area, unproductive labor/delivery, vaginal discharge

Primary Survey Findings

• Male: Abdominal pain, extended penis, inappetence, unilateral swelling of testicles • Female: Active straining for >60 minutes without delivery of a fetus, anorexia, fever, foul-smelling or purulent vulvar discharge, hot/swollen/painful mammary glands, muscle weakness, time delay between pups/kittens >4–5 hours

Equipment

• • • •

Basic crash cart equipment Specialized crash cart equipment Radiology Ultrasonography

Medication

• • • • •

Antibiotics Analgesics Ecbolic agents Metabolic imbalances (e.g., Ca2+, potassium, insulin, dextrose) NSAIDs

Procedures

• Imaging: • Abdominal radiographs • Ultrasonography • Lab tests: • Stat lab database • Vaginal cytology • Blood gas analysis • Manual manipulation, hyperosmotic topical therapy to shrink tissues • Surgery

Monitoring

• • • •

Treatment

Preparation

Presentation

Emergent Condition

7

General: Mentation, body temperature, Elizabethan collar, pain management Cardiovascular: HR and rhythm Renal: Urine output Lab tests: PCV, TP, electrolytes, BUN, creatinine, liver enzymes

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Table 7.16 / Respiratory Emergencies • Aspiration pneumonia, brachycephalic occlusive syndrome, bronchitis, cancer, collapsing trachea, diaphragmatic hernia, feline asthma, flail chest, tracheal and bronchial foreign bodies, hemothorax, laryngeal paralysis, lung contusions, lung parenchymal issues, pleural effusion, pneumomediastinum, pneumonia, pneumothorax, pulmonary edema, smoke inhalation, soft tissue swellings, tracheal stenosis

Presenting Clinical Signs

• Abduction of elbows, cough, flared nostrils, head straightened, hemoptysis, lips drawn back, neck extended, preference to stand or lie in sternal recumbency, reluctance to hold mouth closed, subcutaneous emphysema, wheezing, apnea, dyspnea, open mouth breathing

Primary Survey Findings

• Hyperthermia, ↑ respiratory rate and effort, abnormal respiratory sounds (e.g., laryngeal stridor), irregular respiratory pattern, change in mucous membranes color, tachycardia

Equipment

• Basic crash cart equipment • Specialized crash cart equipment

Medication

• • • • • •

Antibiotics Bronchodilators Cough suppressants Diuretics Steroids Tranquilizers

Procedures

• • • •

Airway suctioning Bronchioalveolar lavage Chest tube placement Imaging: • Thoracic radiographs • Tracheoscopy, bronchoscopy for foreign body retrieval Lab tests: • Stat lab database • Blood gas analysis • Heartworm tests • Fecal analysis • Fluid analysis Oxygen and/or ventilator therapy Surgery Thoracocentesis Tracheostomy, nasal catheter, transtracheal catheter Transtracheal wash

Treatment

•

• • • • • Patient Care

7

Preparation

Presentation

Emergent Condition

322

Monitoring

SECTION THREE: DIAGNOSTIC SKILLS

• General: Pain management, minimal patient handling, calm and quiet environment, turn recumbent patients every 2–4 hours, use harnesses instead of collars • Respiratory: RR and effort, lung sounds, nebulization/coupage • Cardiovascular: HR and rhythm, pulse quality and rate, BP, mucous membranes, SpO2 • Renal: Urine output • Lab tests: Blood gas analysis

Table 7.17 / Toxicologic Emergencies

Patient Care

• Bacterial/fungal toxins, food ingredient (e.g., grapes, onions), household compounds/chemicals, household plants, insecticides, herbicides, medication ingestions/overdoses, pesticides, rodenticides, zinc ingestion

Presenting Clinical Signs

• Ataxia, coma, diarrhea, hyperexcitability, hypersalivation, muscle tremors, progressive depression, stupor, vomiting, weakness, dyspnea, seizures, anuria

Primary Survey Findings

• Abdominal pain, facial edema, hyperthermia, mouth odor, cardiac arrhythmias, cyanosis, pallor mucous membranes, urinary incontinence, vomiting

Equipment

• Basic crash cart equipment • Specialized crash cart equipment

Medication

• • • • • • •

Procedures

• • • • • •

Monitoring

• • • • • •

Treatment

Preparation

Presentation

Emergent Condition

Anticonvulsants Antidote (if available and specific toxin identified) Antiemetics Diuretics Emetics Gastrointestinal protectants Muscle relaxants

7

Bathing, rinsing ECG Enemas Emesis Gastric lavage and charcoal administration Imaging: • Radiographs • Lab tests: • Stat lab database • Ethylene glycol testing • Coagulation testing General: Mentation, body temperature Respiratory: RR and effort Cardiovascular: HR and rhythm, pulse rate and quality, CVP Neurologic: Tremors, seizures Renal: Urine output Lab tests: Electrolytes, BUN, creatinine, urinalysis

CHAPTER 7 / EMERGENCY MEDICINE

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Table 7.18 / Toxins

The goals with poisoning are always the same—prevent further exposure, ↓ absorption, hasten elimination, and provide supportive care. The prognosis for each situation depends on the toxin, quantity, and time delay from initial exposure to toxin.

7

Toxin

Toxic Doses

Clinical Signs

Treatment

Acetaminophen

Canine: 150 mg/kg Feline: 50–60 mg/kg Onset: hours to days

• Brown mucous membranes and blood, depression, facial or paw edema, hepatic necrosis, hypothermia, icterus, vomiting, weakness, cyanosis, dyspnea, tachypnea, keratoconjunctivitis sicca (canine)

• Emesis, gastric lavage, cathartics, oxygen therapy, blood transfusions, diuresis, cimetidine, ascorbic acid • Antidote: 5% N-acetylcysteine (NAC) solution

Amphetamines

1.3 mg/kg Onset: variable

• Agitation, circulatory collapse, coma, hyper- or hypotension, hyperactivity, hypertension, hyperthermia, mydriasis, pallor or hyperemic mucous membranes, ptyalism, restlessness, tremors, tachypnea, cardiac arrhythmias, tachycardia, seizures

• Emesis, gastric lavage, activated charcoal, cathartics, oxygen therapy • Antidote: chlorpromazine

Ethylene glycol

Canine: 4–6 mL/kg Feline: 1.5 mL/kg Onset: 30 minutes–12 hours

• Ataxia, coma, depression, knuckling, lethargy, nystagmus, vomiting, tachypnea, tachycardia, polydipsia, polyuria, seizures

• Blacklight detection, emesis, gastric lavage, supportive care • Antidote: 20% ethanol (feline), 4-methylpyrazole (canine)

Ibuprofen

Canine: 100 mg/kg Feline: 50 mg/kg Onset: 1–4 hours

• Abdominal pain, anorexia, coma, depression, diarrhea, hematemesis, melena, polyuria, stupor, vomiting, seizures

Emesis, gastric lavage, activated charcoal, GIT protectants, diuresis

Metaldehydes • Snail and slug bait

100 mg/kg Onset: 1–4 hours

• Anxiety, ataxia, hyperesthesia, hypersalivation, hyperthermia, incoordination, nystagmus, pulse irregularities, tremors, bradypnea, tachy- or bradycardia, seizures

• Milk, emesis, gastric lavage, activated charcoal • Antidote: none

Organophosphates • Sprays, dusts, dips

Variable Onset: variable

• Colic, diarrhea, hypersalivation, lacrimation, miosis, tremors, vomiting, bronchoconstriction, excessive bronchial secretions, bradycardia, seizures, frequent urination

• Bathing, activated charcoal, cathartics, anticholinergics • Antidote: pralidoxime chloride

Pyrethrins/pyrethroids • Sprays, dips, foggers

Variable Onset: variable

• Anorexia, ataxia, depression, diarrhea, disorientation, hyperactivity, hyperexcitability, hypersalivation, muscle twitching, tremors, vocalization, vomiting, bradycardia, dyspnea, seizures

• Bathing, emesis, gastric lavage, activated charcoal, cathartics, anticholinergics

• Permethrin

Onset: 3–72 hours

• Tremors, seizures

• Bathing (liquid hand soap), methocarbamol, barbiturates, and/or propofol

Insecticides

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SECTION THREE: DIAGNOSTIC SKILLS

Table 7.18 / Toxins (Continued) Toxin

Toxic Doses

Clinical Signs

Treatment

Lily

Onset: 2 hours

• Anorexia, depression, vomiting, polyuria

• Emesis, activated charcoal, cathartics

Mushrooms

Variable Onset: 6–8 hours

• Abdominal pain, ataxia, coma, defecation, depression, diarrhea, DIC, hallucinations, hyperthermia, lacrimation, nausea, salivation, vomiting, seizures, urination

• Emesis, gastric lavage, activated charcoal, cathartics, bowel irrigation, oxygen therapy, supportive care

Pseudoephedrines

5–6 mg/kg Onset: 15–30 minutes

• Agitation, head bobbing, hyperactivity, hypertension, hyperthermia, mydriasis, panting, tremors, cardiac arrhythmias, tachycardia, seizures

• Emesis, gastric lavage, activated charcoal, GIT protectants, diuresis

Anticoagulant • Warfarin, pindone, bromadiolone, brodifacoum, chlorphacinone, difethialone, diphacinone, coumafuryl, dicoumarol, difenamrol

Variable Onset: 6 hours–2 days

• Anorexia, blindness, depression, ecchymoses, epistaxis, exercise intolerance, frank and petechial hemorrhage, hematemesis, hematochezia, lameness, lethargy, melena, pale mucous membranes, paralysis swollen joints, weakness, cough, dyspnea, hematuria

• Emesis, activated charcoal, cathartics, blood transfusions, oxygen therapy • Vitamin K therapy

Bromethalin

Canine: 4.7 mg/kg Feline: 1.8 mg/kg Onset: immediate–2 weeks

• Anisocoria, CNS depression, excitement, forelimb extensor rigidity, head pressing, hyperesthesia, hyperexcitability, hyperthermia, loss of vocalization, paralysis, paresis, Schiff-Sherrington posture, tremors, weakness, seizures

• Emesis, gastric lavage, activated charcoal, cathartics, bowel irrigation, supportive care, diuretics, steroids, Ginkgo biloba • Antidote: none

Cholecalciferol • Vitamin D3

0.1 mg/kg Onset: 12–36 hours

• Anorexia, constipation, depression, hematemesis, hypertension, lethargy, muscle weakness, petechiation, vomiting, ventricular fibrillation, polydipsia, polyuria, seizures

• Emesis, gastric lavage, activated charcoal, cathartics, diuretics, steroids • Antidote: calcitonin, pamidronate

Snakebite envenomation

Variable Onset: immediate

• Dilated pupils, edema, fang marks, hemorrhages, pain, salivation, swelling, tachycardia

• Supportive care • Antidote: antivenin, trivalent crotalidae, atropine

Spider bite envenomation

Variable Onset: immediate-weeks

• Abdominal rigidity, hypersalivation, hypertension, muscle spasms and rigidity, pain, restlessness, salivation, respiratory distress, bronchorrhea

• Supportive care • Antidote: antivenin, dantrolene sodium, Dapsone

Theobromine • Chocolate

10–15 mg/kg Milk chocolate: 44 mg/oz theobromine Baking chocolate: 390 mg/ oz theobromine Onset: 2–4 hours

• Abdominal pain, agitation, ataxia, bloating, coma, cyanosis, diarrhea, hyper- or hypotension, muscle tremors, vomiting, cardiac arrhythmias, tachycardia, seizures, hematuria, polydipsia, polyuria, urinary incontinence

• Emesis, gastric lavage, activated charcoal, cathartics, supportive care, ECG, urinary catheter • Anticonvulsants and antiarrhythmics

Plants

Rodenticides

CHAPTER 7 / EMERGENCY MEDICINE

7

325

Table 7.19 / Trauma Emergencies

Preparation

Presentation

Emergent Condition Presenting Clinical Signs

• Depression, fractures, lacerations, limping, loss of consciousness, pain, panting, shivering, shock, seizures

Primary Survey Findings

• Burns, hemoptysis, hemorrhage, hyper- or hypothermia, necrosis of lips/tongue, pain, petechiation, dyspnea, irregular lung sounds, patterns and rates, maligned or deformed limbs, pneumomediastinum, pneumothorax, pulmonary edema, subcutaneous emphysema, thoracic or abdominal effusion, tachy- or bradycardia

Equipment

• Basic crash cart equipment • Specialized crash cart equipment

Medication

• • • •

Procedures

• • • • •

Monitoring

• • • • •

Patient Care

Treatment

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326

• Animal attack, burns, fractures, hit by car, lacerations

SECTION THREE: DIAGNOSTIC SKILLS

Analgesics Antibiotics Blood transfusions Corticosteroids

Abdominal tap/abdominal pressure wrap Bandaging, splinting, and basic wound care ECG Heat support Imaging: • Thoracic and abdominal radiographs • Spinal and skull radiographs • Ultrasonography • Lab tests: • Stat lab database • Blood gas analysis • Oxygen therapy • Surgery General: Mentation, body temperature, pain management, immobilize as needed Respiratory: RR and effort, lung sounds Cardiovascular: HR and rhythm, pulse rate and quality, BP, ECG, CVP, SpO2 Renal: Micturition reflex, urine output Lab tests: PCV, TP, electrolytes, BUN, blood glucose, blood gas analysis, platelet count

Section

Four

Patient Care Skills Chapter 8: Patient Care 329 Chapter 9: Pain Management 379 Chapter 10: Wound Care 395

Chapter 11: Parenteral Nutrition 413 Chapter 12: Medical Procedures 427

Chapter

8

Patient Care Patient Monitoring 332 Blood Pressure 332 Blood Pressure Procedure 332 Blood Pressure Results 333 Central Venous Pressure 334 Blood Gas Analysis 335 Blood Gas Analysis 335 Arterial Blood Gas Interpretation 337 Acid-Base Disturbances 337 Electrocardiogram 338 ECG Procedure 338 ECG Leads 339 ECG Interpretation 340 Figure 8.1 Normal Canine Electrocardiogram 341 Heart Rate Calculation 342 Common Rhythm Abnormalities 343 Figure 8.2 Atrial Premature Contraction/Complex 344 Figure 8.3 ST-Segment Elevation 344 Figure 8.4 Ventricular Premature Contraction/ Complex 344

ECG Problems and Artifacts 345 Heat Administration 346 Recumbent Patient Care 347 Drug Administration 348 Injections 348 Intravenous Catheter Placement 349 Peripheral and Jugular 349 Arterial and Intraosseous 350 Monitoring and Maintenance 351 Chemotherapy 352 Administration 352 Toxicity 353 Client Education: Monitoring Chemotherapy Response 356 Insulin Therapy 357 Client Education: Insulin Administration 357 Client Education: Monitoring Insulin Response 358 Client Education: Monitoring for Hypoglycemia 359 Fluid Therapy 359 Hydration Assessment 360

8

329

Calculating Fluid Requirements 361 Routes of Fluid Administration 362 Commonly Used Fluids 363 Fluid Additives 365 Calculating Drip Rates 365 Monitoring Fluid Therapy 366 Blood Transfusions 367 Blood Types 368 Blood Collection 369

8

330

SECTION FOUR: PATIENT CARE SKILLS

Blood Products 371 Blood Administration 373 Blood Transfusion Reactions 374 Oxygen Therapy 375 Oxygen Administration 375 Routes of Oxygen Administration 376 Oxygen Hood and Nasal Catheter 376 Transtracheal Catheter and Tracheostomy

377

Key Words and Phrasesa Acidotic Alkalosis Alloantibody Amplitude Antiemetics Antipyretics Apex Ataxia Bipolar Cachexia Carbohydrate Chemo-pin Crystalloids Cyanosis Decubital Diastolic Electromechanical dissociation Epistaxis Erythema Extracellular Extravasation F wave Fructosamine Glycosylated Hemolyzed Holter apparatus Humidification Hypercalcemia Hyperglycemia Hyperkalemia Hypernatremia Hyperoncotic Hypochloremia Hypoglycemia Hyponatremia Hyporeflexia Immunogenic Infarction a

Intracellular Ischemia Isoantibody Manometer Metabolic acidosis Metabolic alkalosis Microaggregates Myelosuppressive Myocardium Nadir Neuropathy Neutropenia Normovolemic Oscillometric Osmotic Osteopenia Papilledema Perfusion Perioperative Petechiae Pollakiuria Polydipsia Polyuria Precordial Prophylaxis Pruritis Repolarization Respiratory acidosis Respiratory alkalosis Serous Stranguria Supraventricular Systolic Tetany Thrombocytopenia Turgor Unipolar Urticaria Vagal

Abbreviations APC, atrial premature contraction/complex APTT, activated partial thromboplastin time aVF, augmented voltage foot aVL, augmented voltage left arm aVR, augmented voltage right arm BG, blood glucose BGC, blood glucose curve bpm, beats per minutes BW, body weight C, Celsius CBC, complete blood count CHF, chronic heart failure CO2, carbon dioxide CPCR, cardiopulmonary cerebrovascular resuscitation CPD, citrate phosphate dextrose CPDA-1, citrate phosphate dextrose adenine CRT, capillary refill time CVP, central venous pressure D5W, 5% dextrose in water DEA, dog erythrocyte antigen DIC, disseminated intravascular coagulation DMSO, dimethylsulfoxide ECG, electrocardiogram E-collar, Elizabethan collar ET, endotracheal tube FeLV, feline leukemia virus FFP, fresh frozen plasma FIV, feline immunodeficiency virus FP, frozen plasma Fr, French FUO, fever of unknown origin GFR, glomerular filtration rate H2O, water IM, intramuscular IO, intraosseous IV, intravenous

Additional Resources, page KCl, potassium chloride kg, kilogram L, liter LA, left arm lb, pound LL, left leg LRS, lactated Ringer’s solution mg, milligram dL, deciliter min, minute mL, milliliter NaCl, sodium chloride NSAIDs, nonsteroidal antiinflammatory drugs O2, oxygen PCV, packed cell volume PPV, positive pressure ventilation pRBCs, packed red blood cells PT, prothrombin time PZI, protamine zinc insulin R, right RA, right arm RBC, red blood cell RL, right leg SA, sinoatrial SIRS, systemic inflammatory response syndrome SQ, subcutaneous STD, standard SWB, stored whole blood TP, total protein V, voltage VPC, ventricular premature contraction/complex WBC, white blood cell

Anatomy, 3 Anesthesia, 439 Blood chemistries, 74 Canine transmissible diseases, 38 Cardiology, 204 Feline transmissible diseases, 44 General medicine, 201 Injections, 348 Laboratory, 71 Nebulization, 432 Nutrition, 57 Radiographs, 159 Surgery, 521 Urinalysis, 147

8

Key words and terms are defined in the glossary on page 631.

CHAPTER 8 / PATIENT CARE

331

PATIENT MONITORING Monitoring of a hospitalized patient is one of the crucial responsibilities of a veterinary technician. This section includes some basic monitoring skills;

blood pressure, central venous pressure (CVP), cardiac values (ECG readings), and heat administration. See Skill Box 13.8, page 467, and Chapter 9 Pain Management, page 379, for further monitoring information.

Blood Pressure Skill Box 8.1 / Blood Pressure Procedure Measuring accurate blood pressures on animals is not trivial, and lots of experience and attention to every detail is important:—limb selection, proper cuff size, snug fit of the cuff, position of the animal—is important so that no weight or pressure is on the measurement limb or cuff, the animal is a relaxed and still. Research has shown that if an animal is upset or agitated due to handling or due to the measurement procedure itself, it will take 8–10 minutes after the animal is calmed and relaxed for the animal’s blood pressure to return to normal. Measurements on an agitated animal are not an indication of their normal blood pressure and are usually worthless clinically when diagnosing a hypertensive animal. 8

Method:

Direct Arterial Pressure

Doppler Ultrasound Flow Detectors

Oscillometric

Indications

• Monitoring during anesthesia, CPCR, shock, fluid administration, and any other condition leading to secondary hyper- or hypotension

• Monitoring during anesthesia, CPCR, shock, and any other condition leading to secondary hyper- or hypotension • Detection of flow in distal limbs (e.g., traumatic wounds, saddle thrombi), corneal flow during CPCR • Irregular pulse signals or rates can indicate cardiac arrhythmias.

• Monitoring during anesthesia, CPCR, shock, fluid administration, and any other condition leading to secondary hyper- or hypotension

Contraindications

• Using large vessels in patients with coagulopathies • Upset or agitated patients

• Upset or agitated patients

• Upset or agitated patients

Setup

• Catheter (e.g., arterial, over-the-needle, through-the-needle) • Heparinized saline • Pressure transducer and monitor

• Equipment • Ultrasonic gel

• Equipment (e.g., petMAP)

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SECTION FOUR: PATIENT CARE SKILLS

Skill Box 8.1 / Blood Pressure Procedure (Continued) Method:

Direct Arterial Pressure

Doppler Ultrasound Flow Detectors

Oscillometric

Procedure

The catheter is placed in an artery (e.g., dorsal pedal, femoral, or auricular) and flushed with 1–1.5 mL of heparinized saline. The catheter is thoroughly secured with tape to avoid dislodging or kinking. The catheter is then labeled to prevent inadvertent intra-arterial injections. The catheter is then connected to the pressure transducer by rigid tubing filled with heparinized saline. Refer to the manufacturer’s guidelines for further setup and monitoring instructions. The method for measuring CVP can also be used if a transducer system is not available.

Place the patient in a comfortable position. Select a cuff that has a width that is approximately 40% of the circumference of the patient’s distal limb or tail. Snugly place the cuff on any place an artery is accessible, typically a limb distal to the elbow or hock or the base of the tail. Place the probe over the artery but distal to the cuff, turn on Doppler, and listen for blood flow. Position probe until a clear flow is heard and tape into place. Inflate the cuff and slowly release the trigger until the first flow sound is heard, this is the systolic pressure. The second sound heard is the diastolic, which often cannot be heard.

Place the patient in a comfortable position. Select a cuff that has a wdith that is approximately 40% of the circumference of the patient’s distal limb or tail. Snugly place the cuff on any place an artery is accessible, typically a limb distal to the elbow or hock or the base of the tail. Connect the cuff to the monitor and turn on. The cuff is inflated until the artery is occluded and then slowly released until the pulse returns. The systolic, diastolic, and mean arterial pressures and heart rate will be displayed.

Complications

• Hemorrhage, thrombosis, infection, and necrosis

• Poor contact between probe and artery

• Poor blood flow, small arteries, movement, shaking, or shivering can lead to inaccurate results.

Tip: Doppler: if the skin is dry, rub in ultrasonic gel first and then apply more when placing the probe over the artery.

Table 8.1 / Blood Pressure Results

The normal and abnormal values for blood pressure measurements are clearly defined in human medicine but have not yet been solidly established in veterinary medicine. The following table shows the ranges currently accepted.

a

Blood Pressure

Normal

Abnormala

Canine

• Systolic: 110–160 mm Hg • Diastolic: 60–100 mm Hg • Mean: 80–120 mm Hg

• Systolic: <80 and >160 mm Hg • Diastolic: >100 mm Hg • Mean: <60 and >120 mm Hg

Feline

• Systolic: 120–170 mm Hg • Diastolic: 70–120 mm Hg • Mean: 80–120 mm Hg

• Systolic: <80 and >160 mm Hg • Diastolic: >120 mm Hg • Mean: <60 mm Hg and >120 mm Hg

Abnormal results do not necessarily warrant therapy.

CHAPTER 8 / PATIENT CARE

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8

Skill Box 8.2 / Central Venous Pressure The CVP measures the heart’s ability to pump fluids returned to it and also evaluates blood volume compared to blood volume capacity. The pressure within the intrathoracic anterior vena cava is compared to a column of water in a manometer or pressure transducer and oscilloscope. Fluctuations are seen with changes in pressure. An ↑ CVP can indicate a backup of blood due to excessive volume (e.g., fluid overload) leading to ascites, pulmonary edema, pneumothorax, or pneumomediastinum. A ↓ CVP can indicate a ↓ blood volume (e.g., dehydration) leading to hypovolemia. An initial crude estimate of CVP can also be done by evaluating resting jugular distention, then filling and relaxation time with digital occlusion. The jugular vein is clipped and observed: Passive • Observed for tension • Mildly distended: often seen with patients in lateral recumbency • Highly distended: patient standing or in sternal recumbency indicates a ↑ CVP • Flat: indicates ↓ CVP and hypovolemia Active Test • Occluded with digital pressure and observed for filling time and then released and observed for relaxation time • ↓ Filling time: >4 seconds indicates ↓ CVP and hypovolemia • ↓ Relaxation time: >2 seconds indicates right side of the heart may be overloaded as with chronic right-sided heart failure, chronic liver disease, acute heart failure 8

Method

Central Venous Pressure

Indications

• Patients prone to hypertension (e.g., renal or liver failure)

Contraindications

• Burn, abrasion, or pyoderma over site, severe coagulopathy, hypercoagulable, or thrombosis of chosen vein inhibiting jugular catheter placement

Setup

• Surgical site preparation materials • IV jugular catheter • Heparinized saline

Procedure

A jugular catheter is placed and advanced to the cranial vena cava. (See Skill Box 8.9 Intravenous Catheter Placement, Peripheral and Jugular, page 349.) Attach an extension set to the catheter, followed by a 3-way stopcock. Attach the IV fluids to the open line of the stopcock. Attach the manometer to the upright opening of the stopcock. Place the patient in sternal recumbency, and position the manometer at the level of the sternum. Turn off the fluids to the patient and fill the manometer with fluids. Open the extension set and the fluid level will equalize. The level at which the fluids stabilizes is the CVP reading. Repeat twice more for accurate results.

Complications

• Blood clots or occlusions can ↑ values. • If fluids are not running through the catheter, flush with heparinized saline every hour.

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SECTION FOUR: PATIENT CARE SKILLS

• 3-way stopcock • Bandaging materials • IV fluid set up

Skill Box 8.2 / Central Venous Pressure (Continued) Method

Central Venous Pressure

Results

Normal: <8 cm H2O Abnormal: >12–15 cm H2O • Monitor trends over time, not a single reading. Following a Fluid Bolus • Normovolemic: ↑ of 2–4 cm H2O with a return to baseline in 15 minutes • Hypovolemic: ↑ with a rapid return to baseline • Hypovolemic (severe): small or no ↑

Tip: Jugular catheter placement can be verified by the 2–5 mm fluctuations seen on the manometer with each respiration.

Blood Gas Analysis 8 Skill Box 8.3 / Blood Gas Analysis Blood gas analysis is used to monitor pulmonary function and the metabolic state of the patient through the delicate balance between carbon dioxide (CO2), bicarbonate (HCO3−), hydrogen (H+), and oxygen (O2). With a change in CO2 or HCO3−, alterations are seen in the body’s pH, ultimately affecting its ability to carry out various enzyme activities. The acid-base equation (CO2 + HCO3 ↔ CO2 + H2O) shows how a change in CO2 or HCO3− can alter the pH. The lungs are primarily responsible for regulating CO2 through respiration, while the kidneys regulate HCO3− through resorption and excretion in the proximal tubule. Because CO2 and HCO3− are the main determinates to the acid-base status (pH) of a patient, a change in one factor can affect the other. For example, it is common to see respiratory changes with metabolic disturbances. The body’s ability to compensate for abnormalities can often mask underlying disturbances, making diagnosis and treatment more difficult. Method

Blood Gas Analysis

Indications

• Patients with respiratory disease and/or metabolic disturbances (e.g., toxins, hypoadrenocorticism, diabetes mellitus, chronic renal failure)

Contraindications

• Patients taking potassium bromide

Setup

• • • • •

25-gauge needle with 1 mL syringe Heparin Cork to cap needle or sterile red top tube Ice bath (for temporary storage) Blood gas analyzer

CHAPTER 8 / PATIENT CARE

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Skill Box 8.3 / Blood Gas Analysis (Continued) Method

Blood Gas Analysis

Procedure

A syringe coated with heparin (1,000 U/mL) is used to obtain a blood sample. A full 1 mL of blood should be obtained to avoid any dilution with heparin. All excess air is expelled from the syringe and the sample is analyzed immediately. If temporary storage is required, the sample can be stored at room temperature for <10–15 minutes or <1–2 hours in an ice-bath once placed in a container with a tight-fitting cap (e.g., cork, rubber stopper, red top tube). Arterial • Femoral or lingual artery (use of other peripheral arteries possible) • Hold off for 3–5 minutes or place temporary pressure wrap to prevent hematoma formation. Venous • Jugular, cephalic, or saphenous vein (use of other peripheral veins possible) • Note: The sample must be protected from air to avoid alterations.

Complications

• Samples stored at room temperature for >20 minutes: ↓ pH • Excessive heparin: ↓ HCO3−

Resultsa

Normal: Arterial pH: 7.35–7.45 PaCO2: 35–42 mm Hg PaO2: 85–105 mm Hg HCO3−: 20–25 mEq/L BE: −4 to +4 Venous pH: 7.35–7.45 PvCO2: 40–50 mm Hg PvO2: 30–42 mm Hg HCO3−: 20–25 mEq/L BE: −4 to +4 Abnormal: • Single or multiple alterations from above • pH: <7.35, acidemia; >7.45, alkalemia

8

a

Slight variations in normal and abnormal results occur throughout literature and instrumentation used. Note: BE: base excess represents the magnitude of acid-base abnormality contributed by metabolic components.

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SECTION FOUR: PATIENT CARE SKILLS

The results of the blood gas analysis are then evaluated to determine the status of the patient. This can often be a tricky process, but the basic interpretation is shown below as a 5-step process.

Arterial Blood Gas Interpretation 1. Evaluate the PaO2 and determine if the patient is hypoxemic (needs oxygen). 2. Evaluate the pH and determine if the patient is normal, acidotic or alkalotic. 3. Evaluate the PaCO2 and determine if it supports the pH findings. • Yes: condition is primarily respiratory • No: condition is not primarily respiratory

4. Evaluate the HCO3− and determine if it supports the pH findings. • Yes: condition is primarily metabolic • No: condition is not primarily metabolic 5. Evaluate the parameter not responsible for abnormal condition to assess for compensation.

Note: Reprinted with permission from Nancy Shaffran, CVT, VTS (ECC).

Table 8.2 / Acid-Base Disturbances

8

Respiratory Acidosis

Metabolic Acidosis

Respiratory Alkalosis

Metabolic Alkalosis

Cause

• Severe pulmonary disease, airway obstruction, pleural effusion, pneumothorax, flail chest, drug side effects, CNS lesions, cardiac arrest, improper use of mechanical ventilator, diseases of respiratory muscles

• Diarrhea, diabetic ketoacidosis, intoxication (e.g., ethylene glycol), hyperphosphatemia, uremic acidosis, post chronic hypocapnia, renal failure

• Intrathoracic disease, fear, anxiety, septicemia, hypoxia, fever, severe liver failure, CNS disease, heat stroke

• Vomiting, drug administration (e.g., sodium bicarbonate, furosemide), post chronic hypercapnia, severe hypokalemia

Clinical Signs

• Anxiety, lethargy (chronic), coma (acute), ↑ mentation, hypoxia, papilledema

• Hyperventilation, hypotension, ventricular fibrillation, anorexia, vomiting, hyperkalemia

• Neurologic (e.g., seizures, tetany), hypokalemia

• No reliable signs • +/− ↑ Respiratory rate, effort and depth

Blood Gas Analysis

• ↓ pH and ↑ PCO2

• ↓ pH and HCO3−

• ↑ pH and ↓ PCO2

• ↑ pH and HCO3−

Treatment

• Oxygen therapy, ventilation support • Treat underlying condition (e.g., thoracocentesis).

• Drug administration (e.g., sodium bicarbonate)

• Fluid therapy (e.g., 0.9% NaCl−) • Drug administration (e.g., potassium)

• Treat underlying condition.

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Electrocardiogram An electrocardiogram (ECG) is a graphic interpretation of the electrical activity of the cardiac muscle. Its use is required for accurate diagnosis of arrhythmias and conduction disorders. An ECG should be a regular part of any systemic disease workup because life-threatening arrhythmias (e.g., ven-

tricular tachycardia, atrial tachycardia) are easily missed on auscultation. Besides physical examination findings indicating an ECG, they are also useful in the preoperative evaluation of geriatrics, in anesthesia monitoring (preoperative, perioperative, and postoperative), and for evaluating the effects of cardiac drugs. This simple procedure provides great diagnostic value and should be routinely used in every veterinary hospital.

Skill Box 8.4 / ECG Procedure

8

Method

Electrocardiogram

Indications

• Cardiac arrhythmias and the status of the myocardium • Tachycardia, bradycardia, extra beats, murmurs, cardiomegaly, and electrolyte disturbances • Exercise intolerance, panting, dyspnea, cyanosis, fainting, seizures, and shock

Contraindications

• If animal is exhibiting severe dyspnea

Setup

• Equipment • Conducting solution (e.g., alcohol, gel) • Staples or wire sutures

Procedure

Using a nonconductive table (e.g., formica or metal covered with a blanket or pad), place the patient in right lateral recumbency or, if critically ill, in any position that does not further increase injury or illness. The limbs should be held parallel to each other and not touching. The forelimbs should be perpendicular to the long axis of the body. If using clips, moisten the areas of attachment with conductive gel, paste, creams, or alcohol. Apply the clips and reapply the conductive agent. • RA/LA: proximal to the olecranon and on the caudal aspect (electrodes may need to be positioned halfway between the olcranon and carpus if cadiac interference is seen) • RL/LL: patellar ligament on the anterior aspect • Cardiac: left intercostal space at costochondral junction, dependent on desired unipolar precordial chest lead Small metal plates covered with conductive gel, paste, or creams can be applied to the pads of the feet, or shave the fur and adhere electrode pads (Holter apparatus) for long-term monitoring. To record the activity of the heart, begin by turning on the machine. Position the stylus in the center of the paper and maintain that position throughout the recording. Turn the sensitivity switch to 1 to allow 1 mV input to move the stylus 1 cm (2 large boxes). (Turn the sensitivity switch to 2 if the tracing is small and unclear or turn it to 1/2 if the tracing is large and extending to the top and bottom of the paper.) Turn the record switch to a paper speed of 50 mm/sec and push the standardization button to record the reference size of 1 mV. Record the desired leads: • Turn the lead selector to 1 and record 2 sets (30 large boxes). • Without turning off machine or changing any other parameters, turn the lead selector to 2 and continue through to aVF and CV6LU (V4). • Turn the lead selector to 2 and record 2–4 feet of lead II rhythm strip at 25 mm/sec. • If precordial chest leads are desired, stop recording and reposition chest lead for each reading. Return the lead selector to STD and push the standardized button. Stop recording and remove clips from the patient. Fold up ECG strip and record the patient’s information (e.g., name, position, excitement level) on the strip.

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Skill Box 8.4 / ECG Procedure (Continued) Method

Electrocardiogram

Complications

• • • •

↑ Stress can exacerbate already critical situations Variations in the body conformation of many dog breeds may alter standard measurements Drug administration (e.g., chemical restraint) may alter recording results If the machine does not have a modern 3-prong plug, attach the ground lead wire to a water pipe or object with a common ground

Tip: When recording an ECG strip, it is best to “drive” with both hands. The left hand is placed on the stylus position knob to help maintain a centered tracing, because they tend to wander during long readings or when switching leads. The right hand is placed on the lead selector switch to change through the various leads smoothly. Tip: ECG activity may continue to appear normal even after all mechanical activity has ceased and the patient has no palpable pulse (e.g., deceased) (electromechanical dissociation). Tip: The teeth of the alligator clips may be bent out, flattened, or filed to improve patient comfort. Tip: Conductive gel, paste, and creams are better at lowering the electrical resistance than alcohol and do not evaporate; however, alcohol-soaked pads may be used between the clip and skin.

Table 8.3 / ECG Leads Lead

Measurement

Movement and Electrode Position

Use

8

Bipolar Standard Leads I

• Measurement between 2 limbs

• R arm (−) → L arm (+. )

II

• R arm (−) → L leg (+. )

III

• L arm (−) → L leg (+. )

• Abnormalities in P-QRST deflections and cardiac arrhythmias • Determining mean electrical axis

Augmented Unipolar Limb Leads aVR aVL

• Measurement from one limb to a point halfway in between the other 2 limbs

• L arm and leg (−) → R arm (+. ) • R arm and L leg (−) → L arm (+. )

• Determining mean electrical axis and heart position • Confirming information gained from other leads

• L arm and R arm (−) → L leg (+. )

aVF Unipolar Precordial Chest Leads CV5RL (rV1) CV6LL (V2) CV6LU (V4) V10

• Measurement from the dorsal and ventral surfaces of the heart • The limb leads form a potential equal to that in the center of the heart, allowing voltage to be measured from the center of the heart to the selected location of the chest lead.

• R and L arm and L leg (−) → 5th R intercostal space near edge of sternum (+. ) • R and L arm and L leg (−) → 6th L intercostal space near edge of sternum (+. )

• R and L ventricular enlargement, myocardial infarction, bundle branch block, and cardiac arrhythmias • Confirming information gained from other leads

• R and L arm and L leg (−) → 6th L intercostal space at costochondral junction (+. ) • R and L arm and L leg (−) → over spinous process of the 7th thoracic vertebra (+. )

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Table 8.3 / ECG Leads (Continued) Lead

Measurement

Movement and Electrode Position

Use

Esophageal

• Measurement from limb and base of the heart • The electrocardiograph is run on and compared with lead I.

• L arm → base of heart

• Rhythm monitoring and accurate identification of P waves

Intracardiac

• Measurement is based on the position of the exploring catheter tip placed through a jugular venipuncture and attached to an outside electrode.

• Dependent on the position of the exploring catheter tip within the heart

• Cardiac arrhythmias (accurate identification of P waves), differentiation between ventricular and supraventricular tachycardia, and for pacing the heart

Invasive Leads

Table 8.4 / ECG Interpretation

8

a b

Cycle Segment

Movementa

Image

Measurementb

Action

P wave

• SA node → R atrium → L atrium → AV node

• Positive wave

• Width: 0.04 second (2 boxes) • Height: 0.4 mV (4 boxes)

• Depolarization of the R and L atrium

P-R interval

• SA node → ventricle

• P wave and ending straight line

• Start of the P wave to start of Q wave (R wave if no Q wave) • 0.06–0.13 second (36.5 boxes)

• Time delay to allow filling of ventricles

QRS

• R bundle branch and L bundle branch → apex and ventricular free walls → basal regions of free walls and septum

• Negative wave (Q) followed by a tall positive wave (R) and ended with a short negative wave (S)

• Start of Q wave to the end of the S wave • Width: 0.05–0.06 second (2.5 boxes) • Height: 2.5–3.0 mV (25–30 boxes)

• Depolarization of the ventricles

ST interval

• Basal regions of free walls and septum → apex and ventricular free walls

• Straight line with no deviations

• End of the QRS complex to the start of the T wave • Width: 0.2 mV (2 boxes) • Height: 0.15 mV (1.5 boxes)

• Early phase of ventricular repolarization

T wave

• Apex and ventricular free walls

• Positive wave

• Height: ≤1/4 of the amplitude of the R wave

• Repolarization of the ventricles

Q-T interval

• R bundle branch and L bundle branch → apex and ventricular free walls → basal regions of free walls and septum → apex ventricular free walls

• Negative wave (Q), tall positive wave (R), short negative wave (S) ending with a straight line (ST segment)

• Start of the Q wave to the end of the T wave

• Summation of depolarization and repolarization of the ventricles

Electrical impulse movement through the heart. Measurement taken at a paper speed of 50 mm/sec.

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8

Figure 8.1 Normal canine electrocardiogram. Reprinted with permission from Larry Patrick Tilley: Essentials of Canine and Feline Electrocardiogram Interpretation and Treatment, 3rd ed. Philadelphia, 1992, Lippincott Williams and Wilkins.

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Skill Box 8.5 / Heart Rate Calculation ECG Paper and Grid Lines 25 mm/sec Small box = 0.04 second Large box (5 small boxes) = 0.20 second Set (15 large boxes) = 3 seconds Rhythm

50 mm/sec Small box = 0.02 second Large box (5 small boxes) = 0.10 second Set (15 large boxes) = 1.5 seconds

Paper Speed 25 mm/sec

50 mm/sec

• Average Heart Rate

Method 1: the number of complete complexes in 1 set × 20 = bpm

Method 1: the number of complete complexes in 1 set × 40 = bpm

• Instantaneous Heart Rate

Method 2: 1500 / the number of small boxes between 2 QRS complexes = bpm

Method 2: 3,000 / the number of small boxes between 2 QRS complexes = bpm

Method 3: 300 / the number of large boxes between 2 QRS complexes = bpm

Method 3: 600 / the number of large boxes between 2 QRS complexes = bpm

Regular Rhythm

8

Method 4: heart rate calculator used according to provided directions Irregular Rhythm • The fraction of the last cycle should be estimated in tenths

342

The number of cycles in 2 sets × 10 = bpm

SECTION FOUR: PATIENT CARE SKILLS

Method 1: the number of cycles in 2 sets × 20 = bpm Method 2: the number of cycles in 4 sets × 10 = bpm • Greater accuracy with slower rates

Table 8.5 / Common Rhythm Abnormalities Rhythm Pattern

Cause

Image

Associated Conditions

Atrial Fibrillation

• Rapid and disorganized depolarization pattern in the atria • ↓ Cardiac output

• Indistinguishable P waves are replaced by numerous F waves. • QRS complexes may be normal or wide with varying amplitude.

• Atrial enlargement, congenital heart defects, drug reactions, anesthesia, heartworm disease, trauma, or hypertrophic cardiomyopathy

Atrial Premature Contraction/ Complex (APC)

• Premature atrial beats originating outside the SA node

• Premature P wave • QRS complexes are normal unless the P wave is so premature they overlap with varying results. • See Figure 8.2.

• Congenital heart disease, cardiomyopathy, electrolyte imbalances, neoplasia, hyperthyroidism, drug reactions, toxemias, atrial myocarditis, or normal variations in aged animals

Respiratory Sinus Arrhythmias

• Irregular sinus rhythm originating in the SA node • Respiratory rate ↑ during inspiration and ↓ during expiration

• Normal sinus rhythm • ↑ Number of cycles during inspiration and ↓ number of cycles during expiration

• Normal finding (brachycephalic), vagal stimulation, and chronic respiratory diseases

ST-Segment Depression

• Net electrical event of myocardial cell repolarization

• Depression of the ST segment of the QRS complex

• Normal finding, myocardial ischemia (inadequate circulation), hyper- or hypokalemia, cardiac trauma, or acute myocardial infarction

ST-Segment Elevation

• Net electrical event of myocardial cell repolarization

• Elevation of the ST segment of the QRS complex • See Figure 8.3.

• Normal finding, myocardial hypoxia (oxygen deficiency), myocardial infarction, or pericarditis

Ventricular Fibrillation

• Weak and uncoordinated ventricular contractions • ↓ To zero cardiac output

• Completely irregular, chaotic, and deformed reflections of varying width, amplitude, and shape

• Shock, anoxia, trauma, electrolyte imbalances, drug reactions, aortic stenosis, cardiac surgery, electric shock, myocarditis, or hypothermia

Ventricular Premature Contraction/Complex (VPC)

• An impulse originating in the ventricles instead of the SA node

• P wave is dissociated from the QRS complex. • Widened and bizarre QRS complex • See Figure 8.4.

• Cardiomyopathy, congenital defects, GDV, drug reactions, myocarditis, cardiac neoplasia, hyperthyroidism, or chronic valvular disease

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343

Figure 8.2 Atrial premature contraction/complex. Reprinted with permission from Larry Patrick Tilley: Essentials of Canine and Feline Electrocardiogram Interpretation and Treatment, 3rd ed. Philadelphia, 1992, Lippincott Williams and Wilkins.

8

Figure 8.3 ST-segment elevation. Reprinted with permission from Larry Patrick Tilley: Essentials of Canine and Feline Electrocardiogram Interpretation and Treatment, 3rd ed. Philadelphia, 1992, Lippincott Williams and Wilkins.

Figure 8.4 Ventricular premature contraction/complex. Reprinted with permission from Larry Patrick Tilley: Essentials of Canine and Feline Electrocardiogram Interpretation and Treatment, 3rd ed. Philadelphia, 1992, Lippincott Williams and Wilkins.

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Table 8.6 / ECG Problems and Artifacts Alteration

Problem

Solution

Baseline not well defined

• Poorly defined baseline

• ↑ the stylus heat and verify whether it is clean • ↓ sensitivity to 1/2 to ↓ the amplitude of the wave

Flat line

• An electrode has fallen off

• Replace electrode that has fallen off: • Lead I works and leads II and III do not—replace L leg • Lead II works and leads I and III do not—replace L arm • Lead III works and leads I and II do not—replace R arm

Negative R wave

• True abnormality • Misplaced electrode

• Verify that the electrodes are placed in the correct position.

QRS complex off the paper

• Excessive amplitude of QRS complex

• ↓ Sensitivity to 1/2 to ↓ the amplitude of the wave

Rapid and irregular vibrations of the baseline

• Muscle tremors • Body movements • Purring

• • • •

Regular sequence of 60 sharp up and down waves

• Electrical interference

• Verify the machine is properly grounded. • Verify the electrode clips are clean, securely attached to skin, and moistened (not saturated) with gel or alcohol. • Verify that the legs are held apart and the clips are not touching each other, and the animal is not touching anything metal (e.g., table). • Verify that the table is not touching electrical cords and is positioned away from electrical wiring. • Verify that the cords are not tangled or coiled up on one another.

Up and down movement of baseline

• Respiratory movements (e.g., panting and coughing)

Verify the patient is in a comfortable position and electrodes are comfortably placed. Place a hand over the chest wall with moderate pressure to ↓ body tremors. Blowing in a cat’s face or gentle manipulation of the larynx to stop purring ↓ Sensitivity to 1/2 to ↓ the amplitude of the wave

• Verify that the patient is in a comfortable position. • Hold the animal’s mouth shut for short periods to obtain each lead.

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8

Skill Box 8.6 / Heat Administration Heat support is required for all animals unable to regulate their body temperature at the normal level (100.5–102.5° F). Anesthetized, severely ill, and/or physically compromised patients are unable to regulate their body temperature and routinely require additional methods of heat support. Hypothermia will significantly slow recovery and severe hypothermia can cause arrhythmias and coagulation problems; prevention is better than management. Alternatively, monitoring the patient who is on heat support is also important to ensure that they do not become overheated or incidentally burned. Hospitalized or anesthetized patients are often unable to move away from an external heat source and often have decreased peripheral blood supply, leading to sometimes severe and extensive thermal burns. Shivering increases oxygen demand by up to 400%; additional oxygen should be provided if a patient is cold and shivering. It is better not to have to warm patients in recovery (e.g., keep them warm under anesthesia). Warming devices should be used immediately; otherwise, cooling will continue. Bair huggers, incubators, IV fluid warmers, and circulating warm air blankets are ideal. Warmed IV fluid bags are not recommended as severe and extensive contact burns occur. Proper padding on all surfaces should be instituted to control heat loss to the undersurface. Rectal temperature is not core temperature but allows trends to be assessed and should be measured regularly to ensure a return to normothermia. Esophageal temperature probes may be reflective of core body temperature in anesthetized patients. Basic heat support that does not require additional equipment includes keeping the patient dry, keeping patients away from air vents and air conditioners, maintaining warm room temperatures, and providing insulation materials against surgery tables and cages. Along with providing heat support, it is also important to ensure heat retention. Many quick methods have been devised, such as wrapping the patient with bubble wrap, placing the patient on foam padding, and placing baby socks on the paws. 8

Method

Use

Comments

Circulating Heated Water Blankets

• Preheated circulating controlled warm water vinyl pad is placed under the patient.

• Thermal burns may occur (rare). • Blankets or other protective coverings are placed on top of the pad to prevent inadvertent puncture. • Provide a minimal amount of heat support.

Heated Air Blankets (Bair Huggers)

• Blanket is placed over the patient. • Place a cotton blanket over the blanket or gown for maximum effectiveness.

• Do not use over transdermal medication as ↑ drug delivery and subsequent overdose may occur. • Do not place blankets over the patient’s head as corneal drying may occur. • Use caution when using in surgery to avoid circulating contaminated air; do not turn on until patient is fully prepped and draped.

Heated Bags

• Expired IV fluid bags, rice or oat bags • Wrap the bag in a blanket or towel and place to the side of the patient.

• Not recommended as severe thermal burns often occur • Bags should never be placed on top, underneath, or next to a shaved area of skin. • Remove bag once it has cooled to prevent reverse heat exchange.

Hot Line IV Fluid Warmer

• Fluids are warmed within the administration set using metal warming channels or multilumen circulating warm water.

• Additional methods can be used alone or along with fluid warmers; running the fluid administration set through a bowl of hot water, placing a circulating heated water blanket around the line, coiling the line under the patient’s heat source.

Warm Blankets and Towels

• Blankets and towels warmed by a clothes dryer

• Amount and length of heat are limited.

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Skill Box 8.7 / Recumbent Patient Care Decubital sores (pressure sores), urine and fecal scalding, and lung atelectasis can be the source of further patient complications and can lead to ↑ morbidity and mortality. Recumbent patients with neurologic or orthopedic disease are at the greatest risk of acquiring these complications. Appropriate and observant nursing care should prevent or identify these complications in their early stages. Early identification will minimize the impact they place on the patient. Patients should be lifted and turned as dragging or pulling across the floor can lead to disruption in skin integrity and the beginning of decubital sores. Condition

Cause

Prevention

Treatment

Comments

Decubital Sores

• Excessive pressure, friction, or shearing forces over a bony prominence resulting in local or regional ischemia • Anatomical differences: thin breeds (↓ muscle or fat padding over bones), obese or large and giant breeds (excessive weight and pressure), thick hair coat (trapping of moisture and inability to monitor skin changes) • Underlying disease conditions: paralysis, inability or unwillingness to change position, malnutrition, impaired circulation, metabolic disease, thick hair coat

• Identifying at-risk patients • Monitor daily for early signs (e.g., erythema, edema, tenderness, exudate, alopecia) • Adequate nutritional status • Beds (e.g., hammocks, air or water mattresses) • Bedding (e.g., orthopedic pads, thick blankets) • Keeping the patient’s skin clean and dry • Repositioning every 2–4 hours • Passive exercise and massage to circulation

• Relieve pressure (e.g., “doughnuts,” inflatable rings). • Clip and clean with an antiseptic. • Drug administration (e.g., systemic antibiotics) • Debridement, surgical and wound management (See Chapter 10 Wound Care and Bandaging, page 395.)

• Greater trochanter is the most common site, but additional pressure points of forelimbs and hindlimbs are also seen. • Obtain bacterial swabs prior to cleaning.

Urine and Fecal Scalding

• Exposure to urine or feces for extended periods of time or with compromised skin integrity

• • • •

Clean bedding Grates Beds (e.g., nylon mesh hammock) Protective topical ointments (e.g., petrolatum) applied to the perineal and inguinal areas • Bathing

• Clip and clean with an antiseptic • Drug administration (e.g., silver sulfadine, systemic antibiotics) • Debridement, surgical and wound management (See Chapter 10 Wound Care and Bandaging, page 395.)

• Patients with urinesoaked fur should assumed to have urinesoaked skin. • Can result in severe dermatitis and predispose to decubital ulcers

Lung Atelectasis

• Extended periods of one-sided recumbency

• Repositioning every 2–4 hours

• Reexpansion (e.g., repositioning, removal of air or fluid from pleural space)

• Auscultation reveals localized areas of dullness.

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DRUG ADMINISTRATION Skill Box 8.8 / Injections Subcutaneous Injection (SQ)

Intramuscular Injection (IM)

Intravenous Injection (IV)

Location

• Typically between the scapulas, but could be anywhere the skin can provide a tent for injection

• Lumbar region, semimembranous, and semitendinosus muscles

• Any accessible vein (e.g., external jugular vein, cephalic vein, saphenous vein, pedal veins, lingual vein during anesthesia)

Volume

• Fluid administration: 50–100 mL in one location depending on the size and species of the animal

• <3 mL per site

• Large volumes can be administered.

Technique

• Gently pull an area of skin up to form a small “tent.” Insert the needle with the bevel side up at a 15° angle through the center of the “tent.” You should feel the needle pop through the skin. Aspirate for blood and then inject the contents intended.

Rear Leg • Place the needle at least a thumb’s width from the femur. Inject the needle in a slightly caudal direction, aspirate for blood and inject the contents of the syringe. • Avoid: sciatic nerve, femoral artery and vein, popliteal lymph node and the femur Lumbar Region • Place your thumb on the wing of the ilium and your middle finger on a vertebra of the spine. Let your index finger fall naturally; where it lands is the location for the injection. Inject the needle straight into the muscle, aspirate for blood, and inject contents of syringe. • Avoid: all nerves and blood vessels

Jugular Vein • Occlude the vein in the jugular furrow at the thoracic inlet with thumb of nonsyringe hand. The head should be slightly rotated toward the injection site for better visibility. The jugular vein typically lies in the cowlick of the fur running from the ramus of the mandible to the thoracic inlet. Insert the needle parallel to the skin in a cranial direction, aspirate for blood, either inject contents of syringe or withdraw blood. • Avoid: the carotid artery Peripheral Vein • Once vein is occluded by either a tourniquet or assistant, lay thumb alongside the vein to stabilize it. Insert the needle parallel to the skin in a cranial direction, aspirate for blood, either inject contents of syringe or withdraw blood. • Avoid: all nerves

Tips

• Changing needles before injection; use of a 25-gauge needle • Gently squeezing or flicking the injection site to dull the area • Distraction (e.g., treats, sliding the patient across the table or lifting their front legs, twitching a ear or tapping the nose, talking to the patient).

• Pinching the injection site before administration desensitizes the area. • Changing to a 25-gauge needle also provides a less painful injection, because the new needle is not dull and is smaller. • Distract the animal while giving the injection.

• Use EMLA on prepared skin to desensitize the animal’s reaction to insertion of the catheter. Place 1 g on shaved area, cover with dressing, and wait a minimum of 1 hour for full effect. • Gentle insertion of the needle typically results in much less of a reaction than thrusting. • Distract the animal while giving the injection.

8

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Intravenous Catheter Placement Catheters are used in veterinary medicine to gain access to the vascular system for administration of medications or fluids as well as to obtain blood

samples. The following section explains the various techniques and their care. Being able to place a catheter quickly is a valuable skill in a technician.

Skill Box 8.9 / Intravenous Catheter Placement: Peripheral and Jugular Method

IV Catheter, Peripheral

IV Catheter, Jugular

Indications

• IV access for fluids, medications, and anesthesia • Central line placement is desired and a jugular vein is not available.

• IV access for fluids, medications, and anesthesia • Patients with poor peripheral veins or circulation, CVP measurement or reliable blood sampling

Contraindications

• Burn, abrasion, or pyoderma over site, thrombosis of chosen vein, and infusion of hyperoncotic solutions (parenteral nutrition)

• Burn, abrasion, or pyoderma over site, severe coagulopathy, hypercoagulable, or thrombosis of chosen vein

Catheter Sites

• Cephalic and saphenous veins • Pedal vein (contraindicated with hypertonic fluids)

• External jugular vein and femoral vein

Setup

• Surgical site preparation materials • 1/2 and 1 inch tape

• • • •

Procedure

Clip a wide area of hair leaving a 2″ border above and below the catheter insertion point. Wash hands and put on gloves. Apply Nolvasan from a yoker bottle and using cotton balls, wipe the skin gently. (Avoid vigorous scrubbing) Follow with an alcohol soaked cotton ball to wipe the area being sure not to introduce bacteria from the outer edges of the clipped site. Follow the above steps using Technicare. As the final prep, apply Technicare, but do not wipe off with alcohol. Change gloves. Perform a cut down if necessary with the tip of a sterile needle. Insert catheter SQ and then penetrate the vessel. Cap the catheter with a T-port and flush with saline and secure with tape. Additional bandaging may be placed in long term catheters, however less is typically more in this case.

• • • •

IV catheter Saline flush T-port 22-gauge needle

Surgical site preparation materials Sterile gauze: 3X3 1 /2 and 1 inch tape IV catheter

• • • •

Saline flush T-port primed with saline 22-gauge needle Lidocaine 2%

8

Set up all required materials. Hold off the jugular vein and carefully clip the area of the insertion site, avoiding clipper burn. (If the animal is in sternal recumbency, the person who is placing the catheter holds off the vein; if the animal is in lateral recumbency, the restrainer holds off the vein.) Wash hands, put on gloves and follow scrub technique for peripheral catheter placement. Change to sterile gloves, tent the skin, place the needle under the skin near the vessel at a 30–45° angle. While maintaining the same catheter angle, palpate the vessel and advance only the tip of the catheter into the vein. A “pop” should be felt. A flashback is not seen in many jugular catheters until aspirated. Thread the catheter the rest of the way into the vein. If there is a needle guard, place the needle in the groove and clamp shut. Be sure the hub of the catheter is locked into the hub of the needle. Remove the stylet and attach the T-port. Aspirate and then flush with 3–6 mL heparinized saline. Place a butterfly tape around the catheter hub and secure the catheter. The needle guard can be used to suture the catheter in place, or a butterfly tape can be applied to provide more stability. Adhere the catheter to the skin with 3 simple interrupted nonabsorbable sutures (one on each side of the catheter and a third as an anchor). Place triple antibiotic ointment over the catheter entry site. Place a drop of glue to the catheter/ needle hub if applicable to the catheter type. Place a second strip of tape in a counterclockwise direction. Apply cast padding loosely around the animal’s neck clockwise and then counter clockwise, keeping the T-port clear. Apply the gauze wrap in the same manner. Flush T-port with heparinized saline, aspirate, and then flush again. Place a layer of elastic tape, testing the tightness by ensuring that 2 fingers can be inserted under the wrap. Place a piece of tape to secure the T-port and write the date of placement on it. Radiographs can be taken to assess proper placement.

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Skill Box 8.9 / Intravenous Catheter Placement: Peripheral and Jugular (Continued) Method

IV Catheter, Peripheral

IV Catheter, Jugular

Complications

• Phlebitis, nonpatent, and FUO

• Phlebitis, nonpatent, FUO, facial and front limb edema

Removal

• Remove after 72 hours. • Tape is cut with bandage scissors and catheter is slowly pulled out. • A cotton ball and Vet-Wrap bandage is placed for 1–2 hours

• Remove after 72 hours. • Tape is cut with bandage scissors and catheter is slowly pulled out. • A cotton ball and Vet-Wrap bandage is placed for 1–2 hours

Tip: The right external jugular maintains a straighter course and is often preferred for jugular placement.

Skill Box 8.10 / Intravenous Catheter Placement: Arterial and Intraosseous 8

Method

IV Catheter, Arterial

IV Catheter, Intraosseous

Indications

• Blood gas analysis, continuous blood pressure monitoring, blood sampling

• CVP fluid administration

Contraindications

• Drug or fluid administration • Burn, abrasion, or pyoderma over site • Thromboembolic disease, hypercoagulopathy, and ambulatory patients

• Osteopenia or infected tissue over the site

Catheter Sites

• Dorsal pedal, femoral, and auricular arteries

• Greater trochanter of the proximal femur, flat medial aspect of the proximal tibia (in obese animals), and greater tubercle of the humerus

Setup

• • • • • •

• • • • • •

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Surgical site preparation materials /2- and 1-inch tape IV catheter Saline flush T-port 22-gauge needle

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Surgical site preparation materials Sterile gauze: 3 × 3 inches 1 /2- and 1-inch tape IV catheter Saline flush T-port primed with saline

• • • • • •

22-gauge needle Lidocaine 2% No. 15 or No. 11 scalpel blade 16-gauge bone marrow needle Suture material Triple antibiotic ointment

Skill Box 8.10 / Intravenous Catheter Placement: Arterial and Intraosseous (Continued) Method

IV Catheter, Arterial

IV Catheter, Intraosseous

Procedure

Follow peripheral catheter protocol. Place a gauze square just below the insertion site to help maintain an aseptic area as well as absorb any blood. Using a smooth and steady technique, insert the catheter with bevel side facing up into the artery at a 30–45° angle. A flashback of blood is seen upon entering the artery. Palpate the pulse and then advance the catheter toward the strongest area of pulse; withdraw the needle stylet. Blood should be seen at the hub of the catheter. Cap the catheter with a T-port and flush with saline and secure with tape. Label the catheter as arterial.

Set up all required materials. Clip the greater trochanter and scrub with chlorhexidine soaked gauze, using aseptic technique. Inject a bupivacaine or lidocaine subcutaneously if the animal is responsive (0.1 mL at the catheter insertion site). Place a sterile gauze square just below the insertion site to help maintain an aseptic area as well as absorb any blood. Incise the insertion site with a No. 15 or No. 11 scalpel blade. Using sterile technique and the leg in adduction, place one hand along the side of the femur with the thumb pointing toward the greater trochanter. Pass the catheter through the insertion site, down the medial aspect of the greater trochanter, and into the trochanteric fossa. Push the catheter through the cortex by applying downward pressure and rotating a quarter turn with each rotation. A loss of resistance is felt when the catheter passes through the cortex. The catheter will bounce lightly down the bone. Verify placement by aspirating and observing for bone marrow particulates and by rotating the femur; the catheter and femur should move as one. Remove cap and stylet and attach fluid set. Secure into place by suturing tape attached to the catheter to the skin. Secure in place with bandage material.

Complications

• Venous puncture, phlebitis, nonpatent, and FUO

• Osteomyelitis, fractures, growth plate damage, and displacement

Removal

• Remove after 3–5 days. • Tape is cut with bandage scissors and catheter is slowly pulled out. • A pressure wrap is placed for 10 minutes, followed by a cotton ball and Vet-Wrap bandage for 1–2 hours.

• Remove after 3–5 days. • Tape is cut with bandage scissors and catheter is slowly pulled out.

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Tip: Use EMLA on prepared skin to desensitize the animal’s reaction to insertion of the catheter. Place 1 g on shaved area, cover with dressing, and wait a minimum of 1 hour for full effect. Tip: Securely attach the tape to the catheter by making a tape butterfly. Leave approximately 1 inch of tape on either side of the catheter and then loop the tape back onto itself such that there is a 1-inch “wing” on either side of the catheter. Use these wings to suture the catheter in or as an additional spot of contact when taping around the circumference of the limb of the patient.

Skill Box 8.11 / Intravenous Catheter Monitoring and Maintenance Patient Care

Equipment Care

• Monitor for signs of fever, lethargy, or changes in vital signs in the animal (which may represent sepsis).

• Swab injection ports on catheter and fluid bags with an antimicrobial solution prior to each injection.

Catheter Care

• Replace T-ports and administration sets every 24 hours or sooner with obvious wear or contamination, especially in critically ill and immunosuppressed patients.

• Flush catheter every 4–6 hours with saline to assess patency and patient response. • Remove bandaging every 24 hours to observe for phlebitis, swelling, redness, pain, hot to the touch and displacement. • Replace catheters every 3–5 days or sooner if warranted. • Replace bandaging every 24 hours, when soiled or wet.

• Observe strict aseptic technique when changing administration sets and fluid bags. Note: In discontinuing fluid therapy, fluids should not be stopped abruptly, especially with patients receiving high flow rates. Slowly weaning the patient off fluids over 24 hours allows the kidneys to adjust and again concentrate urine well, to avoid continuous excessive fluid loss.

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Chemotherapy As the number of clinics providing chemotherapy administration increases, it is important for the safety of the person administrating, the owner, and the patient to have the appropriate safety information available. Proper training is essential as these drugs are considered potentially hazardous.

Routes of exposure include absorption, inhalation, and ingestion. Each clinic should have documented preparation, storage, and disposal protocols for the various agents. Chemotherapy administration should take place in a well-ventilated, low-traffic area of the hospital.

Skill Box 8.12 / Chemotherapy: Administration Steps

Preparation

1. Drug Calculation

• Review the patient’s record, and recheck the chemotherapy protocol and drug calculations. • It is best to have a second person confirm the drug calculations. Note: Chemotherapy drugs differ as to their body weight calculations (e.g., kilograms, pounds, or square meters): be sure to verify the correct form. Also, most drugs are based on lean body weight, not actual body weight.

2. Personnel Supplies

Prepare yourself and assistant with safety gear regardless of administration technique: • Latex gloves: high-risk gloves or 2 pairs regular gloves Tip: With 2-pair system, wear 1 pair under the cuff of gown and 1 pair over the cuff of the gown. • Full face shield or protective eyewear • Mask: dust or mist respirator or a mask with a filter

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Note: Surgical masks do not have a filter and are not sufficient. • Gown: disposable with long sleeves, closed front, and cuffs 3. Administration Supplies

Oral • Chemotherapy agent • Hemostat or pill-gun

4. Drug Preparation

1. 2. 3. 4. 5. 6. 7. 8. 9.

SQ/IM • Alcohol-soaked gauze sponges • Chemo-pin • Drop cloth with plastic backing • Chemotherapy agent • Gauze sponges • Syringe

IV Same as above and along with • Catheter • Clippers • Scrub preparation materials • Tape

Preparation in a well-ventilated area. Remove plastic cover of vial, and wipe the top with an alcohol swab. Insert the chemo-pin into the vial. Attach syringe to the chemo-pin while holding the vial upright. If adding a diluent, add slowly and then mix contents of vial completely, with the Luer-Loc syringe left in place. Turn vial upside down and aspirate drug into syringe slowly to avoid excess air bubbles. Push any excess air back into the syringe before separating from vial. Wrap gauze around the connection between the syringe and vial and gently pull apart. Place a covered needle onto the syringe.

Tip: Do not inject air into the vial; maintaining a negative pressure within the vial reduces the risk of aerosolization. • When not using a chemo-pin, all the above steps are accomplished with a needle attached to the end of a Luer-Lok syringe. • Do not fill a syringe more than 2/3 full, to prevent the plunger from detaching from the syringe. • If an agent is to be administered via a fluid bag, fill the administration set with plain diluent before adding the chemotherapy agent to reduce the risk of contamination when attaching the line to the patient.

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Skill Box 8.12 / Chemotherapy: Administration (Continued) Steps

Preparation

5. Patient Preparation

1. 2. 3. 4.

6. Drug Administration

1. With an alcohol-soaked gauze around the end of the catheter, insert the needle into the catheter and administer the drug at the correct rate but at an even pace to avoid leakage around venipuncture site. 2. Flush the catheter with 3–5 mL nonheparinized 0.9% sodium chloride after administration to avoid irritation to the vein. 3. Monitor for allergic reactions for up to 1 hour after administration of certain drugs (e.g., L-asparginase). 4. Apply a pressure wrap after removing the catheter, and maintain pressure for several minutes. • Place an alcohol-soaked gauze sponge over the injection site whenever inserting or removing the needle or catheter to avoid aerosolization of the drug. • Do not aspirate the drug back into the catheter after administration to avoid dilution and residual drug in the catheter injection port.

7. Disposal

1. Place all items in a zip-lock bag to prevent aerosolization. 2. Dispose of the waste into an appropriate biohazard container. 3. Clean the preparation and administration surfaces thoroughly.

Select vein: peripheral veins are recommended because they provide better visualization of any drug that becomes extravascular. Aseptically clip and prepare the site. Place a catheter: butterfly, over-the-needle, or through-the-needle intracatheter. Ensure patency of the catheter by flushing at least 12 mL nonheparinized 0.9% sodium chloride. • Once a vein has been unsuccessfully punctured, a new vein should be used. If this is not possible, it is recommended that time be allowed for the proper clotting to occur before a proximal site is used. • Heparinized saline should not be used as it may cause the drug to form a precipitate.

8

Tip: Before removing gloves, place capped syringes and any other used products that may aerosolize into your hands, pull gloves off over the materials, and then dispose of them. 8. Post Patient Care

1. Wear double layer of gloves when handling waste from the patient for the first 72 hours. 2. Wipe down cages as using a hose or spray may aerosolize excreted drugs. 3. Closely monitor response to drug (e.g., attitude, appetite, eliminations, and general behavior).

Table 8.7 / Chemotherapy: Toxicity

Chemotherapy is the process of administering drugs to attack actively growing and dividing tumor cells. Unfortunately, these agents are not selective for tumor cells and will also attack other cells (e.g., bone marrow cells, gastrointestinal cells). With the administration of any chemotherapy agent, the patient must be monitored for adverse reactions and toxicities. Toxicities may not appear for several days following administration or until an accumulation of toxic levels have been obtained within the body. Most protocols are generally designed to result in <5% hospitalization rate (e.g., sepsis) for chemotherapy toxicity and <1% direct mortality rate from any particular toxicity.

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Table 8.7 / Chemotherapy: Toxicity Treatment

Comments

• Neutropenia • Anemia, thrombocytopenia (rare)

Neutropenia • <1000–2000/μL • ↓ Dose by 10–25% • <1500/μL • ↓ Dose by 10–25% • Drug administration (e.g., trimethoprim-sulfa, fluoroquinolones) • Monitor temperature. Neutropenia and fever • Hospitalization, IV fluids, antibiotics, blood work, blood culture, urinalysis and culture, thoracic radiographs, ± colony-stimulating factors Thrombocytopenia • Delay administration when platelet counts are <50,000–100,000/μL

• CBC and platelet count are required 12–24 hours before all chemotherapy agents known to cause myelosuppresive (e.g., cisplatin, carboplatin, doxorubicin). • Severely neutropenic patients may not be able to show signs of infection or fever. • Nadir is typically seen 5–10 days after administration. • Delay of chemotherapy for 1 week typically allows for bone marrow recovery.

• Arrhythmias • Acute, rare, transient • Cardiomyopathy • Chronic, cumulative

Prevention • Drug administration with iron-chelating cardioprotective agents (e.g., dexrazoxane) • Drug infusion over 15 minutes or a CRI over several hours • ECG monitoring Treatment • Discontinue drug use if rhythm abnormalities are seen. • Drug administration (e.g., antiarrhythmics)

• Mostly seen with canine doxorubicin administration • Limit total cumulative dose to <180 mg/m2 as a guideline for doxorubicin. • Cardiotoxicity is almost always irreversible and fatal.

• Alopecia, delayed hair regrowth, hyperpigmentation, hair color alterations

• No treatment necessary

• Mostly seen in nonshedding breeds (e.g., Poodle, Terriers, Old English Sheepdog). • Regrowth seen soon after discontinuing chemotherapy. • Change in color or textures may be initially seen, but often resolves with time.

• Local tissue necrosis • Secondary to extravasated agent

Prevention • Meticulous catheter placement and monitoring Treatment • Discontinue infusion. • Do not remove needle; withdraw as much of the drug as possible. • Inject 10–20 mL of sterile saline and dexamethasone (1–4 mg) into the area of extravasation. • Vincristine: • Instill 1 mL of hyaluronidase (150 units/mL) for every mL extravasated. • Apply warm packs for 24–48 hours to site. • Doxorubicin: • Instill 10 times the amount of DHM3 or dexrazoxane IV for the amount extravasated and SQ at the site of extravasation. • Apply cold packs for 6–10 hours to site. • Cisplatin • Instill 1 mL of isotonic sodium thiosulfate for every mL extravasated.

• Mostly seen with vincristine, doxorubicin, and cisplatin. • Sloughs typically appear at 7–10 days and should be treated as an open wound. • Bandages and E-collars can be used to avoid additional self-trauma. • ± Use of topical DMSO and infiltrated hydrocortisone (doxorubicin and vincristine) • Warn of potential for limb amputation if severe necrosis.

Cardiac

Hematologic

Complication

Dermatologic

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Comments

• Nausea, inappetence, vomiting, diarrhea, enterocolitis

• Symptomatic therapy (e.g., highly palatable food, appetite stimulants, antiemetics, motility modifiers) • Severe: • IV fluids • Nutritional support • Antibiotic therapy • Preemptive antiemetics (e.g., odansetron)

• Mostly mild and self-limiting, except cisplatin, which can be severely emetogenic • Typically occur 5–7 days post administration

Hypersensitivity

Complication

• Urticaria, erythema, restlessness, head shaking, vomiting • Cardiovascular collapse (canine, rare), anaphylaxis • Respiratory distress (feline)

Prevention • Drug administration (e.g., diphenhydramine, dexamethasone) Treatment • Slowing or discontinuing drug infusion in hypersensitive patients • IV fluids • Drug administration (e.g., dexamethasone, epinephrine) preemptively or during symptoms

• Mostly seen with doxorubicin and L-asparaginase administration

• Cerebellar ataxia • Peripheral neuropathy (e.g., constipation, hyporeflexia, weakness, motor dysfunction)

Peripheral neuropathy • Bulk laxatives • Remain within guidelines of dosages (e.g., 5-FU < 20 mg/kg PO)

• Mostly seen with 5-FU (cerebellar ataxia) and vincristine (peripheral neuropathy)

• Nephrotoxicity

• IV fluid diuresis (pre and post) • Monitor serum creatinine and urine specific gravity

• Mostly seen with cisplatin (canine) and doxorubicin (feline) • Avoid use in canines with existing renal insufficiency.

• Hemorrhagic cystitis • Stranguria, pollakiuria, hematuria

Prevention • Altering dosing frequency or drug choice • Administer in the morning to allow more time to empty bladder. • Drug administration (e.g., furosemide) • IV diuresis around time of injection • Provide access to fresh water and frequent trips outside. Treatment • Drug administration (e.g., NSAIDs, DMSO, 1% formalin)

• Mostly seen with canine cyclophosphamide administration • Do not repeat if cystitis occurs. • Mild cases are often self-limiting.

• Acute collapse and shock

• Aggressive fluid therapy • Labwork monitoring

• Rare condition • Extensive treatment for lymphoma or leukemia with rapid tumor breakdown

Acute Tumor Lysis Syndrome

Urologic

Gastrointestinal

Treatment

Neurologic

Table 8.7 / Chemotherapy: Toxicity (Continued)

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Skill Box 8.13 / Client Education: Monitoring Chemotherapy Response Patients receiving chemotherapy should be closely monitored by their owners to evaluate their response to treatment. Often clients are overly concerned about the health of the animal and therefore should be given guidelines as to when to call the clinic and when to monitor at home. Educating the client can give them the information and tools to make basic care decisions at home. Clinical Signs

8

When to Call Monitor

Call Clinic

Appetite

• Picky, but still eats treats

• Inappetance

Attitude

• Slightly lethargic

• Lethargic and/or reluctant to move

Bowel movements

• Soft stool

• Diarrhea

Temperature

• ≤103° F

• >103° F

Urination

• Normal

• Bloody urine

Vomiting

• Single event

• Frequent and retching

• Wear double-layer gloves when cleaning up urine, feces, or vomitus for 48 hours after receiving chemotherapy and follow proper disposal guidelines. • Maintain a low-stress environment. • Ensure proper scheduling of the next chemotherapy administration and follow-up evaluations and lab work.

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Insulin Therapy Skill Box 8.14 / Client Education: Insulin Administration Not all insulin syringes are alike, which can lead to incorrect dosage of insulin. Insulin syringes are typically found in 100-unit and 30-unit sizes. The 100-unit syringes are numbered in 10s with the smallest lines each measuring 2 units of insulin. The 30-unit syringes are numbered in 5s with the smallest line each measuring 1 unit of insulin. When administering small amounts of insulin it is advisable to use 30 unit syringes so as to ensure accuracy. Care must be taken to verify the type of syringe after purchase and before administration. Variations can also exist in the concentration of insulin; Vetsulin and PZI are U-40 with each 1 mL containing 40 units of insulin, while Glargine and Humulin R and U are U-100, with each 1 mL containing 100 units of insulin. Not being aware of this difference can greatly overdose or underdose a patient. Preparation

Drawing Up the Medication

Administering the Insulin

• See Table 17.30 Metabolic Drugs: Pancreatic, page 600. • Do not shake the vial; gently roll it between the palm of your hands to mix. • Use a new syringe for each injection.

1. Pull back the plunger of the syringe to position the top of the plunger (part closest to the needle) at the desired dose. 2. Insert the needle into the vial, and inject the air to prevent a vacuum in the vial. 3. Slowly pull back on the plunger to the desired amount and withdraw the needle from the vial. 4. Check to make sure there are no bubbles in the syringe; if present, pull back on the plunger, and tap the syringe to move the bubbles to the top. Then push the plunger until all the air is out of the syringe. 5. Verify the correct amount of insulin is within the syringe.

1. Locate an area anywhere from mid neck to the last rib and halfway down on either side, changing with each injection. 2. Place your index finger against the back of the animal and use your thumb and middle finger to pull up skin to form a “tent” under your index finger. 3. Insert the needle, bevel side up, into the skin at a 45° angle. 4. Pull back on the plunger to verify no blood or air fills the syringe; if present, remove needle and try again. 5. Depress the plunger to insert the insulin under the skin. 6. Remove the syringe and immediately recap it. 7. Properly dispose of the syringe and needle.

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Skill Box 8.15 / Client Education: Monitoring Insulin Response When caring for a diabetic patient, diligent monitoring both at home and along with careful veterinary management must take place to achieve the appropriate patient plan. Along with monitoring for life-threatening hypoglycemia, hyperglycemia must also be monitored to evaluate the patient’s response to insulin and to detect any early complications. With the initiation of insulin therapy, the protocol will vary until the patient has become regulated. To monitor long-term insulin therapy with veterinary management, physical examinations are scheduled every 2–6 months and serum fructosamine or glycosylated hemoglobin concentrations are obtained. The success of the treatment of most diabetic patients lies in the hands of the owner, their attention to detail and keen observations are critical. At home monitoring includes the parameters listed below; all results should be relayed to the veterinarian so adequate dose adjustments can be made.

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• Monitor • Appetite • Attitude • Body condition • Polydipsia/polyuria • Urine glucose/ketone levels • Initially, monitor daily and then 2–4 times monthly. • Urine glucose should maintain 0–1+. • Consistent high results (>2+) may require ↑ dose and consistently low results (0) may require ↓ dose as directed by veterinarian. • Positive results may be seen with excitement, ↑ carbohydrate intake and corticosteroid administration. • See Tips under Urogenital Procedures for collecting urine samples at home, page 434. • Glucometer • Fasting blood glucose (BG) twice weekly and blood glucose curve monthly or as directed by veterinarian • BGC • Necessary to assess insulin efficacy, peak and duration of effect, and degree of fluctuations • At home monitoring: • Test every 2 hours (every 4 hours with Glargine) starting before the morning insulin and ending after the following morning insulin dose. • Ideal BGC results show the nadir (lowest BG) between 100–150 mg/dL halfway between dosing intervals. • A variety of glucometers are available for home monitoring. • Blood samples are obtained from the capillary bed of the ear margin, foot pads, and (canine only) lip, elbow callus, and base of tail.

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Skill Box 8.16 / Client Education: Monitoring for Hypoglycemia Hypoglycemia is the condition of a low blood glucose level, too low to effectively fuel the body’s blood cells. This is often seen when there is a relative or absolute excess of insulin circulating in the bloodstream caused by; too much insulin administered, missed or delayed meal, eating a smaller than normal meal, vomiting a meal, strenuous exercise, stress and certain medications. With a blood glucose level <60 mg/dL, most animals will exhibit a drunken state and the administration of a carbohydrate source will show a quick recovery. Animals with a blood glucose level <20 mg/dL often lose consciousness and seizures may occur; the administration of a carbohydrate source should be immediately instituted followed by immediate medical attention. Signs to Watch for

Actions to Take

Prevention

• • • • • •

• Give a carbohydrate source orally (e.g., Karo syrup, maple syrup). • Seek veterinary care immediately. • Keep the animal warm.

• Feed the animal the same food and amount at the same times every day. • Do not feed table scraps or any diet other than the agreed-on diabetic diet. • Feed multiple meals each day. • Provide fresh clean water at all times. • Maintain a consistent exercise program. • Do not administer insulin to a patient that is not eating unless directed to do so by the veterinarian.

Depression, lethargy Deviations from normal behavior Drunken state (e.g., stumbling, staggering) Lack of appetite Panting Seizures, comas

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FLUID THERAPY Fluid administration is necessary when an animal is dehydrated, experiencing shock, losing blood, or having a surgical procedure that may result in excessive blood loss or has a disease that is resulting in depletion of the animal’s normal fluid, electrolyte, or acid-base balances. Dehydration may lead to hypovolemia and hypoperfusion. Fluid requirements are based on an animal’s hydration status, reason for

fluid loss, and physical condition. The veterinarian is responsible for prescribing the appropriate fluid therapy. Obtaining the following assessments will assist the veterinarian in the calculation of fluid requirements for the animal. Distinction between dehydration and perfusion status is an important factor in the veterinarian’s choice of fluid therapy. The following charts are to provide the technician with information to help understand the veterinarian’s fluid therapy plan and to assist in the process of administration.

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Skill Box 8.17 / Hydration Assessment

Physical Examination

Assessment of Hydration

Medical History

Laboratory Assessment

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360

Hydration Significance

Assess Dehydration Status • Skin turgor: assess the amount of time it takes for the skin to return to the animal’s body when gently pulled up and twisted at the back of the neck or along the spine. Use 2 or 3 assessment locations. • Obesity can falsely ↓ turgor, and emaciation can falsely ↑ turgor. • Mucous membranes: assess for dryness of gums and cornea (moist, tacky, dry) • Eye position: assess the degree of eye sinkage into the bony orbit Assess Perfusion Status • Capillary refill time: direct digital pressure is applied to the mucous membranes until blanched and then timed for blood (pink color) to return (normal: <1–2 seconds) • Heart rate and pulse (femoral and metatarsal): assess heart rate, pulse (amplitude and duration) • Canine: 70–180 bpm • Feline: 110–220 bpm • Weight of the animal: Patient’s normal body weight and current weight should be noted. 1 lb. body weight = 1 pint (480 mL) fluid

<5%: normal hydration • No obvious clinical sign • Skin turgor: <2 seconds 6%–8%: mild dehydration • Skin: Inelastic and leathery • Twist: disappears immediately • Skin turgor: >3 seconds • Eyes: duller than normal and sunken • Mucous membranes: tacky to dry 8%–10%: moderate dehydration • Skin: inelastic and leathery • Twist: disappears slowly • Skin turgor: >3 seconds • Eyes: duller than normal and sunken • Mucous membranes: tacky to dry • Heart rate: ↑ 10%–12%: severe dehydration • Skin: no elasticity • Twist: remains indefinitely • Skin turgor: remains indefinitely • Eyes: dry, deeply sunken • Mucous membranes: dry, cyanotic, and possibly cold • CRT: prolonged or absent • Heart rate: ↑ • Pulse: weak 12%–15%: patient is in shock and death is imminent

Packed cell volume • Canine: 37%–55% • Feline: 24%–45%

• Dehydration at >45%

Total protein, serum • Canine: 5.4–7.6 g/dL • Feline: 6.0–8.1 g/dL

• Dehydration at >8.0 g/dL

Urine specific gravity • Canine: >1.035 • Feline: >1.040

• Evaluates kidney function more than hydration status, only reflects dehydration if kidneys are healthy.

CVP • <8 cm H2O • Monitor trends over time, not a single reading

• See Skill Box 8.2 Central Venous Pressure, page 334. • Assesses true venous return to the heart • Low pressure reflects low effective circulating volume.

Serum lactate

• ↑ Serum lactate may indicate poor perfusion.

Patient’s history

Fluid Loss • Amount of vomiting, diarrhea, and salivation • Amount of fluid and food intake

Review of patient’s file

• Previous physical problems (e.g., heart disease, kidney diseases) will influence fluid therapy

SECTION FOUR: PATIENT CARE SKILLS

Skill Box 8.18 / Calculating Fluid Requirements The rates shown below are for those patients without pulmonary, cardiac or severe renal disease and are able to handle total rapid or high fluid rates. Veterinarians will need to prescribe the actual amount, the type of, and the rate of the fluid to be administered. Purpose

Basis of Calculations

Rate

Rehydration

Basic Rehydration Formula • Calculates the fixed rate of replacement fluids to correct the deficit over 4–6 hours

• % dehydrated × body weight (kg) × 1000 mL/kg = mL of fluid replacement Example: Animal weighing 20 kg is dehydrated 6%. Fluid needed for basic rehydration is calculated as: 0.06 × 20 (kg) × 1000 (mL/kg) = 1,200 mL

Maintenance Calculation • Calculates the amount of fluid to replace losses resulting from urination, feces, respiration • Panting and fever will ↑ amount of fluid loss (evaporative loss).

• 40–60 mL/kg/day in a mature animal • Dependent on the cause of the loss and animal’s condition

Ongoing losses • Calculates the amount of fluid loss attributable to excessive vomiting, diarrhea, polyuria, and third spacing of body fluids

• 20 mL vomit = 20 mL fluids

Anesthetic Protocol

• Calculated on expected fluid loss during surgery (e.g., blood)

• Healthy patients, elective procedures: 5 mL/kg/hr • 5–15 mL/kg/hr • Adjustments made based on patient’s status (e.g., blood pressure, perfusion)

Postoperative Protocol

• Calculated to account for rehydration, maintenance, and ongoing losses

• Evaluation rehydration above

Pediatric Protocol

• Calculated to account for the rapid water turnover of neonates as their body weight is 80% water

• 60–180 mL/kg/day

Shock Protocol

• Calculated to establish a circulating blood volume to allow adequate tissue perfusion

• Crystalloids • Canine: 40–90 mL/kg/hr • Feline: 20–60 mL/kg/hr • Colloids • Canine: 15–20 mL/kg, increments of 5 mL/kg over 15 minutes • Feline: 25 mL/kg/day, administered over 30–40 minutes • Rates are adjusted when crystalloids and colloids are given concurrently. • Rates are indicated when the patient has adequate/normal cardiopulmonary function.

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Table 8.8 / Routes of Fluid Administration Route

Indication

Complications

Notes

Oral

• Minimal fluid loss • Recent anorexia, neonates

• Tracheal intubation and aspiration, vomiting, regurgitation, aerophagia

• Contraindicated: vomiting, diarrhea, dysphagia, or life-threatening situations (e.g., shock) • Administration by bottle, syringe, or enteral feeding tubes

Subcutaneous Dorsal Midline Dorsal Flanks

• Mild to moderate dehydration • Maintenance

• Injection site infection (rare) • Do not use >2.5 % dextrose, as sloughing and abscesses may occur

• Contraindicated: infected or devitalized skin, hypothermia, or severely dehydrated • Warmed to body temperature and allow flow by gravity • Use only isotonic fluids. • Use several sites; no more than 10–20 mL/kg. • Absorption is expected within 6–8 hours. • Technique: See Skill Box 8.8 Injections, page 348.

Intravenous

• Severe dehydration • Condition of animal is severe • Perioperative precaution

• Phlebitis, septicemia, embolism, volume overload

• • • • •

Intraperitoneal

• Mild to moderated dehydration • Large volumes

• Peritonitis and intraabdominal abscess

• Contraindicated: ascites, peritonitis, sepsis, pancreatitis, or expected abdominal surgery • Warmed to body temperature isotonic fluids • Absorption can take up to 20 minutes. • Used to treat severe hyper- or hypothermia • Technique: the caudal abdomen is aseptically prepared. An 18–22 gauge needle is inserted on the ventral midline, caudal to the umbilicus. The syringe is aspirated, if no fluid is seen (e.g., blood) the fluids are attached and administered. If fluid is seen, the needle is removed and repositioned.

Intraosseous

• Small animals (<5 kg), neonates, or animals with poor venous access

• Osteomyelitis, fractures, and growth plate damage

• Flush catheter with heparinized saline every 4–6 hours if fluid therapy is discontinued. • An IV catheter should be placed as soon as a site allows (24–72 hours). • All intravenous medications and fluids can be administered IO. • Technique: See Skill Box 8.10 Intravenous Catheter Placement: Arterial and Intraosseous, page 350.

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Contraindicated: anemia Warmed to body temperature Requires rate calculation Requires closer monitoring; especially in cardiac insufficiency cases Flush catheter with heparinized saline every 6–12 hours; replace catheter every 72 hours. • Technique: See Skill Box 8.9 Intravenous Catheter Placement: Peripheral and Jugular, page 349.

Table 8.9 / Commonly Used Fluids

Selecting the type of fluid to administer can be as important as the selected route and rate. In selecting a fluid, it is important to know the electrolyte status of the patient and the underlying disease. From this information, fluids are then chosen based on a composition that best fits the patient’s condition and need. Colloids are most commonly used in shock, severe hypoalbuminemia, sepsis, SIRS, and hypotension, as they replace intravascular fluids. Due to the large-molecular-weight substances, colloids remain in the plasma compartment, leading to volume expansion. Synthetic colloids are chosen when the albumin is >2 g/dL; patients with albumin <2 g/dL require natural colloids (e.g., plasma, pRBCs). Crystalloids are the most commonly used extracellular replacement fluid, due to reduced expense, availability, and rapid rate of correcting volume deficits. Crystalloids contain electrolyte and nonelectrolyte solutes and are able to enter all body fluid compartments. However, only 20–33% remains in the vascular space 30 minutes and 10–20% 1 hour after administration.

Synthetic Colloids

Fluid Type

Indications

Route

Comments

Dextran 70

• Volume expansion • Shock therapy

IV slowly

• Monitor cardiac function. • Allergic responses (rare) • Possible coagulopathies, ↑ BG levels, altered TP and blood crossmatching results • Remains within the vascular space for 4–8 hours

Hetastarch

• Hypoproteinemia • Shock therapy

IV

• • • •

• Volume expansion • Anemia and shock due to tissue hypoxia

IV

Oxyglobin

Allergic responses, mostly cats, and eliminated with slow infusion Possible coagulopathies and ↑ amylase Remains within the vascular space for 12–48 hours ↑ Osmotic and oncotic pressure of blood

8

• Oxygen-carrying capacity for up to 40 hours • Altered serum chemistries and bilirubinuria • Slow infusion and diligent monitoring required to avoid fluid overload in normovolemic patients. • Used within 24 hours after removing the foil packaging • Indicated for dogs only

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Table 8.9 / Commonly Used Fluids (Continued)

8

Crystalloids

Fluid Type

364

Indications

Route

Comments

Dextrose 5% in Water (D5W) • Isotonic

• Free water deficits • Calories (179 kcal/L) • Hypernatremia

IV

• High dosages or prolonged use may produce pulmonary edema and dilution of electrolytes • Incompatible with penicillins

Lactated Ringer’s • Isotonic

• • • •

IV, SQ

• Contraindicated: hepatic disease, hypercalcemia, hyperkalemic, hyperlactatemic • Incompatible with cephalothin sodium and chlortetracycline

Normosol-R • Isotonic

• Replacement fluid • Maintenance fluid • Acidotic states

IV, SQ

• Contraindicated: cancer, hypercalcemia, hyperkalemic • May sting when given SQ

Plasma-Lyte A • Isotonic

• • • •

IV, SQ

• Contraindicated: hyperlactatemic, hypercalcemia, hyperkalemic • May sting when given SQ

Ringer’s Solution • Isotonic

• Replacement fluid • Corrects metabolic alkalosis

IV, SQ, IP

• Monitor: electrolyte concentrations and pulmonary function

0.45% Sodium Chloride (NaCl) • Hypotonic

• • • •

IV

• Contraindicated: shock therapy • Used for patients with high risk of fluid retention

0.9% Sodium Chloride (NaCl) • Isotonic

• Replacement fluid • ↑ Plasma volume • Hyponatremia, hypochloremia, hyperkalemia, hypercalcemia • Bathes tissue during surgical procedures • Shock therapy

IV, SQ, IP

• Contraindicated: sodium restricted cases, heart failure, hypertension, metabolic acidosis • Monitor: electrolyte concentrations and pulmonary pressure • Long-term infusion may cause electrolyte imbalances • Incompatible with amphotericin B

7.5% Sodium Chloride (NaCl) • Hypertonic

• Volume expansion • Shock therapy

IV

• Normal hydration required before use • Administered in small boluses (e.g., 3–5 mL/kg) • Monitor: CVP, electrolytes

SECTION FOUR: PATIENT CARE SKILLS

Replacement fluid Maintenance fluid (short term) Acidotic states Shock therapy

Replacement fluid Maintenance fluids Acidotic states Shock therapy

Long term fluid therapy Free water deficits Hypernatremia Sodium restrictions

Table 8.10 / Fluid Additives Additive

Indications

Route

Comments

Calcium Gluconate and Calcium Chloride

• Correction of hypocalcemia • Eclampsia

IV slowly

• Contraindicated: hypercalcemia and ventricular fibrillation • Rate is variable depending on condition and other laboratory values. • Monitor: hypercalcemia, hypotension, cardiac arrhythmias (when given in conjunction with potassium), cardiac arrest and venous irritation • Calcium gluconate compatible with D5W, NaCl, LRS, dextrose/NaCl combinations and dextrose/LRS combinations

Dextrose 50%

• Hypoglycemia • Caloric supplementation

IV

• Contraindicated: hyperglycemia • See Skill Box 17.1 Basic Calculations, page 570.

Potassium Chloride (KCl)

• Prevention or correction of hypokalemia

SQ, IM

• Contraindicated: hyperkalemia, acute renal failure, acute dehydration and severe hemolytic reactions • Rate of infusion is critical: • IV: ≤0.5 mEq/kg/hr, do not exceed 40 mEq/L • SQ: ≤30 mEq/L • Must be diluted • Monitor: hyperkalemia, bradycardia, or arrhythmias • Compatible with all commonly used IV fluids • Acidosis may show falsely ↑ K+ levels and alkalosis falsely ↓ K+ levels. • Protect fluid bag from light.

Sodium Bicarbonate

• Correction of metabolic acidosis • Hypercalcemic and hyperkalemic crises

IV

• • • • •

Vitamin B Complex

• Anorexic patients

SQ, IM, IV

• Necessary for sufficient energy metabolism (e.g., glucose, fat, protein) • Protect fluid bag from light.

Contraindicated: metabolic or respiratory alkalosis, hypochloremia and LRS fluids Caution: congestive heart failure or other edema-causing conditions Rate is variable depending on condition and other laboratory values. Monitor: blood gas measurements and acidosis status Compatible with D5W, NaCl, dextrose/NaCl combinations

Skill Box 8.19 / Calculating Drip Rates 1. Number of mL needed/Time in which the fluid can be administered (in minutes) = mL/min

Example: Need 1200 mL to be given over 5 hours, using a 15 drops/mL administration set:

2. mL/min × drops/mL of the administration set = No. of drops/min

[1200 divided by (5 hours multiplied by 60 min/hr)] multiplied by 15 drops/mL = 60 drops/min or 1 drop/sec

3. No. of drops/min divided by 6 = No. of drops/10 seconds or No. of drops/min divided by 60 = No. of drops/second if the flow rate is high

[1200/300] × 15 = 60 drops/min or 1 drop/sec

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8

Table 8.11 / Monitoring Fluid Therapy

8

Physical

Monitoring fluid therapy for the desired effect as well as potential adverse effects is necessary for a successful outcome. No one parameter or value can evaluate fluid therapy; it is a combination of results and trends over time. Along with monitoring the patient for dehydration and overhydration, the equipment (e.g., catheter, administration set, fluid bag, pump) must also be monitored for proper function.

366

Assessment

Dehydration

Normal

Overhydration

Comments

Blood Pressure

• Hypotension

• See Table 8.2, Blood Pressure Results, page 337.

• Hypertension

• See Table 8.1 Blood Pressure Procedure, page 335.

Capillary Refill Time

• ↓ CRT

• 1–2 seconds

• ↑ CRT

• Assesses peripheral perfusion

Heart Rate, Pulse Rate, and Effort

• Tachycardia • Weak pulses

• Canine: 70–180 bpm • Feline: 110–220 bpm

• Tachycardia, gallop • Strong or bounding pulses

• Assesses cardiovascular status and intravascular fluid volume status

Mentation

• Depressed, dull

• Calm, relaxed

• Agitated, restless

Physical Examination

• Sunken eyes

• See Table 2.2 Physical Examination, page 18.

• Serous nasal discharge, ↑ jugular pulses, pitting edema, chemosis, dyspnea

• Performed multiple times a day to evaluate hydration and calculate ongoing losses

Pulmonary Auscultation

• N/A

• Heard equally on both sides • Smooth, quiet sound

• Cough, pulmonary edema, harsh lung sounds, crackles, rales

• See Table 2.3 Pulmonary Examination, page 32.

Respiratory Rate and Effort

• Variable

• Canine: 10–30 breaths/min • Feline: 25–40 breaths/min

• Tachypnea, dyspnea

Skin Turgor

• ↓ Skin turgor

• <2 seconds

• ↑ Skin turgor

• See Table 8.17 Hydration Assessment, page 360.

Urine Output

• <1 mL/kg/hr

• 1–2 mL/kg/hr

• Alteration from normal

• Assesses renal function and perfusion (GFR)

Weight

• ↓ Weight

• Variable

• ↑ Weight

• Monitor weight 3–4 times a day with aggressive fluid administration and daily with maintenance rates. • ↑ Weight may be a sign of developing pulmonary edema or elevated CVP. • An ↑ of 1 kg equals 1 L of fluid. • Body weight ↑ by the % of dehydration indicates a need to change to a maintenance fluid rate from that point forward.

SECTION FOUR: PATIENT CARE SKILLS

Laboratory

Table 8.11 / Monitoring Fluid Therapy (Continued) Assessment

Dehydration

Normal

Overhydration

Comments

Central Venous Pressure

• −2 to +5 cm H2O

• <8 cm H2O

• >10 cm H2O or an ↑ of more than 5 cm H2O within a 24hour period

• Assesses true venous return to the heart • Low pressure reflects low effective circulating volume. • High pressure may reflect fluid overload, rightsided myocardial failure, or restrictive pericarditis.

Electrolytes

• N/A

• See Table 4.2 Blood Chemistries, page 76.

• N/A

• Evaluated to determine the need for replacement therapy

Packed Cell Volume

• ↑ PCV, >50%

• Canine: 37%–55% • Feline: 24%–45%

• ↓ PCV, <20%

• Assesses hydration status and hemodilution effect of rapid crystalloid infusion

Temperature

• Variable

• 100.5–102.5° F

• Hypothermia, shivering

• A rise of 1.8° F may require a 10% ↑ in the maintenance fluid rate.

Total Protein

• >8.0 g/dL

• Canine: 5.4–7.6 g/dL • Feline: 6.0–8.1 g/dL

• <4.0 g/dL

• Assesses the relative serum oncotic pressure • A ↓ in oncotic pressure allows more fluid to flow into the interstitium, causing edema (e.g., pulmonary, SQ).

8

BLOOD TRANSFUSIONS Blood transfusions have become very popular with the wide availability of blood products. National commercial animal blood banks have been established along with many in-hospital donor programs. With this available

treatment option, increased knowledge has been gained, leading to the promotion of blood component therapy. Treating each patient according to their individual needs with specific blood components decreases the possibility of transfusion reactions and allows multiple patients to benefit from each unit of blood.

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367

Table 8.12 / Blood Types

The first step to performing a blood transfusion is the full understanding of blood types for both the canine and feline. Misinformation in this step can lead to serious transfusion reactions and even death. Blood types are distinguished by different genetic markers on the surface of the RBC. These genetic markers are antigenic and to different degrees cause the immune system to react to unmatched transfused blood to form antibodies (alloantibodies or isoantibodies). These antibodies are found in the plasma and can lead to reactions that can cause minor to severe transfusion reactions. Dogs have more than 12 different blood groups and multiple blood types. The genetic markers on the surface of the RBC are known as dog erythrocyte antigens (DEAs). Dogs do