Veterinary Necropsy Guide

Preface xv List of Contributors xvii Acknowledgments xix About the Companion Website xxi Part I Necropsy Fundamentals 1 1 Introduction to the Necropsy 3 1.1 What Is a Necropsy? 3 1.2 Why Do a Necropsy? 3 1.3 What Information Can and Cannot Be Gained from a Necropsy 3 1.4 When to Refer a Necropsy 4 2 Necropsy Basics 6 2.1 Necropsy Facilities 6 2.2 Necropsy Equipment 6 2.3 Safety Considerations 10 2.3.1 Cuts and Punctures 10 2.3.2 Slips and Falls 11 2.3.3 Zoonotic Disease 11 2.3.4 Formalin 12 2.4 The Importance of a Good History 12 2.5 The Necropsy Report 12 2.5.1 Gross Description 12 2.5.2 Gross Findings 13 2.5.2.1 Inflammatory Lesion 13 2.5.2.2 Fluid in a Body Cavity 13 2.5.2.3 Hemorrhage in an Organ 13 2.5.2.4 Neoplasm, Congenital Defect 13 2.5.3 Gross Diagnosis 13 2.5.4 Comment 13 2.6 Postmortem Changes 14 Part II The Mammalian Necropsy 17 3 The Necropsy 19 3.1 Introduction 19 3.2 Small Animal Necropsy Technique 19 3.2.1 Weigh the Body 19 3.2.2 External Examination 19 3.2.3 Reflect the Skin and Right Limbs 20 3.2.4 Open the Abdominal Cavity 23 3.2.5 Puncture the Diaphragm 23 3.2.6 Open the Thoracic Cavity 24 3.2.7 Open the Pericardium 25 3.2.8 In Situ Examination of Organs 25 3.2.9 Remove the Adrenal Glands 25 3.2.10 Remove the Pluck 26 3.2.11 Remove the Gastrointestinal Tract, Liver, and Spleen 27 3.2.12 Remove the Urogenital Organs 29 3.2.13 Remove the Head 29 3.2.14 Take Out the Eyes 29 3.2.15 Remove the Brain 30 3.2.16 Remove the Pituitary Gland 32 3.3 Modifications for Large Animals 32 3.4 Modifications for Pocket Pets 37 4 The Integumentary System 39 4.1 Anatomy Review and Species Differences 39 4.1.1 Dermis and Epidermis 39 4.1.2 Hair 39 4.1.3 Sweat Glands 41 4.1.4 Sebaceous Glands 41 4.1.5 Mammary Glands 41 4.1.6 Claws 42 4.1.7 Horns 42 4.2 Organ Examination and Sampling 42 4.2.1 Primary Lesions 43 4.2.2 Lesions That May Be Primary or Secondary 44 4.2.3 Secondary Skin Lesions 44 4.2.4 Sampling the Skin 45 4.3 Special Techniques 46 4.3.1 Cytology 47 4.3.2 Skin Scrapes 47 4.3.3 Hair Examination (Trichogram) 47 4.3.4 Hoof/Claw/Nail 47 4.4 Common Artifacts, Incidental Findings, and Postmortem Changes 47 4.5 Common, Classic, and Pathognomonic Lesions 48 5 The Musculoskeletal System 49 5.1 Anatomy Review and Species Differences 49 5.1.1 Bones and Joints 49 5.1.2 Teeth 52 5.1.3 Skeletal Muscle 53 5.2 Organ Examination and Sampling 55 5.2.1 Bones 55 5.2.2 Joints, Tendons, and Ligaments 56 5.2.3 Skeletal Muscle 56 5.3 Special Techniques 56 5.4 Common Artifacts, Incidental Findings, and Postmortem Changes 58 5.5 Classic or Pathognomonic Lesions 58 6 The Cardiovascular System 60 6.1 Anatomy Review and Species Differences 60 6.1.1 Right Heart 60 6.1.2 Left Heart 63 6.1.3 Vessels: Great and Small 63 6.1.4 Embryology, Fetal Circulation, and Congenital Defects 63 6.2 Organ Examination and Sampling 66 6.3 Special Techniques 68 6.4 Common Artifacts, Incidental Findings, and Postmortem Changes 69 6.5 Common, Classic, or Pathognomonic Lesions 71 7 The Respiratory System 72 7.1 Anatomy Review and Species Differences 72 7.2 Organ Examination and Sampling 77 7.2.1 Larynx and Trachea 77 7.2.2 Lungs 78 7.2.3 Nasal Cavity and Sinuses 79 7.3 Special Techniques 79 7.4 Common Artifacts, Incidental Findings, and Postmortem Changes 80 7.5 Common, Classic, and Pathognomonic Lesions 81 8 The Alimentary System 82 8.1 Anatomy Review and Species Differences 82 8.1.1 The Oropharyngeal Cavity 82 8.1.2 The Salivary Glands 82 8.1.3 The Esophagus 82 8.1.4 The Mesentery and Omentum 85 8.1.5 The Stomach 85 8.1.6 The Small Intestine 86 8.1.7 The Large Intestine 87 8.1.8 The Intestinal Vasculature and Nervous System 88 8.2 Organ Examination and Sampling 88 8.2.1 The Esophagus 88 8.2.2 The Gastrointestinal Tract 89 8.3 Special Techniques 90 8.4 Common Artifacts, Incidental Findings, and Postmortem Changes 90 8.5 Common, Classic, and Pathognomonic Lesions 91 9 The Liver and Pancreas 93 9.1 Anatomy Review and Species Differences 93 9.1.1 The Liver 93 9.1.2 The Pancreas 96 9.2 Organ Examination and Sampling 97 9.2.1 The Liver 97 9.2.2 The Pancreas 98 9.3 Special Techniques 99 9.4 Common Artifacts and Postmortem Changes 99 9.4.1 The Liver 99 9.4.2 The Pancreas 99 9.5 Common, Classic, and Pathognomonic Lesions 100 10 The Urogenital System 101 10.1 Anatomy Review and Species Differences 101 10.1.1 Urinary Tract 101 10.1.2 Reproductive Tract 103 10.1.3 Fetal Membranes and Placenta 103 10.1.4 Umbilical Cord 106 10.2 Organ Examination and Sampling 108 10.2.1 Kidneys 109 10.2.2 Ureters 109 10.2.3 Bladder and Urethra 109 10.2.4 Ovaries 109 10.2.5 Oviduct/Uterus/Cervix/Vagina 110 10.2.6 Testes/Epididymides/Ductus Deferens 110 10.2.7 Accessory Sex Glands 110 10.2.8 Fetus, Umbilical Cord, and Fetal Membranes 110 10.2.9 Distal Colon/Rectum/Anus 112 10.3 Special Techniques 112 10.4 Common Artifacts and Postmortem Changes 113 10.5 Common, Classic, and Pathognomonic Lesions 114 11 The Nervous System 115 11.1 Anatomy Review and Species Differences 115 11.2 Organ Examination and Sampling 116 11.2.1 Brain 116 11.2.2 Spinal Cord 120 11.2.3 Peripheral Nerves 121 11.3 Special Techniques 121 11.4 Common Artifacts, Incidental Findings, and Postmortem Changes 121 11.5 Common, Classic, and Pathognomonic Lesions 123 12 The Eye and Ear 124 12.1 Anatomy Review and Species Differences 124 12.1.1 The Eye 124 12.1.2 The Ear 125 12.2 Organ Examination and Sampling 127 12.2.1 The Eye 127 12.2.2 The Ear 128 12.3 Special Techniques 129 12.3.1 The Eye 129 12.3.2 The Ear 130 12.4 Common Artifacts, Incidental Findings, and Postmortem Changes 131 12.5 Common, Classic, or Pathognomonic Lesions 131 13 The Endocrine System 132 13.1 Anatomy Review and Species Differences 132 13.1.1 The Pituitary Gland 132 13.1.2 The Thyroid and Parathyroid Glands 132 13.1.3 The Endocrine Pancreas (Islets of Langerhans) 134 13.1.4 The Adrenal Glands 134 13.2 Organ Examination and Sampling 135 13.2.1 The Pituitary Gland 135 13.2.2 The Thyroid and Parathyroid Glands 135 13.2.3 The Endocrine Pancreas 136 13.2.4 The Adrenal Glands 136 13.3 Special Techniques 137 13.4 Common Artifacts and Postmortem Changes 137 13.5 Common, Classic, and Pathognomonic Lesions 137 14 The Lymphoreticular System 139 14.1 Anatomy Review and Species Differences 139 14.1.1 Thymus 139 14.1.2 Lymph Nodes 139 14.1.3 Spleen 141 14.1.4 Bone Marrow 143 14.1.5 Tonsils 143 14.1.6 Hemal Nodes 143 14.2 Organ Examination and Sampling 143 14.2.1 Thymus 143 14.2.2 Lymph Nodes 144 14.2.3 Spleen 145 14.2.4 Bone Marrow 146 14.2.5 Tonsils 146 14.2.6 Hemal Nodes 147 14.3 Special Techniques 147 14.4 Common Artifacts, Incidental Findings, and Postmortem Changes 147 14.5 Common, Classic, or Pathognomonic Lesions 148 Part III Nonmammalian Necropsies 149 15 Birds 151 15.1 Anatomy Review and Species Differences 151 15.1.1 Integument 151 15.1.2 Musculoskeletal System 153 15.1.3 Cardiovascular System 154 15.1.4 Respiratory Tract 154 15.1.5 Alimentary Tract 155 15.1.6 Hepatobiliary System 156 15.1.7 Urogenital System 157 15.1.8 Nervous System 157 15.1.9 Endocrine System 157 15.1.10 Lymphatic System 158 15.1.11 Special Sense Organs 159 15.2 Safety Considerations 159 15.3 Necropsy Procedure 159 15.3.1 External Examination 159 15.3.2 Skinning the Carcass 159 15.3.3 Opening the Coelomic Cavity 159 15.3.4 Initial Tissue Collection 160 15.3.5 Examination of Organ Systems 160 15.3.6 Brain, Eyes, Joints, Peripheral Nerves, and Bone Marrow 160 15.4 Special Procedures 161 15.5 Common, Classic, and Pathognomonic Lesions 161 16 Reptiles 162 16.1 Anatomy Review and Order Differences 162 16.2 Safety Considerations 166 16.3 Necropsy Procedure 166 16.3.1 External Examination 166 16.3.2 Accessing the Coelom 166 16.3.3 Internal Examination and Organ Removal 168 16.4 Common Artifacts, Incidental Findings, and Postmortem Changes 170 16.5 Common, Classic, and Pathognomonic Lesions 171 17 Amphibians 172 17.1 Anatomy Review and Order Differences 172 17.2 Larval Amphibian Anatomy 176 17.3 Safety Considerations 178 17.4 Necropsy Procedure for Adult Amphibians 178 17.5 Necropsy Procedure for Larval Amphibians 179 17.6 Fixation, Decalcification, and Trimming Considerations 179 17.7 Common Artifacts, Incidental Findings, and Postmortem Changes 180 17.8 Common, Classic, and Pathognomonic Lesions 180 18 Fish 181 18.1 Anatomy Review 181 18.2 Species Differences 182 18.3 Safety Considerations 183 18.4 Necropsy Procedure 184 18.5 Special Techniques 187 18.6 Common Artifacts, Incidental Findings, and Postmortem Changes 187 18.7 Common, Classic, and Pathognomonic Lesions 188 Part IV Additional Testing 189 19 Cytology 191 19.1 Types of Cytology Preparations 191 19.2 Making a Touch Imprint 191 19.3 Making a Bone Marrow Smear 191 19.4 Other Preparations 192 19.5 Staining 192 19.6 Atlas of Normal Tissues 193 20 Histopathology 196 20.1 Necropsy Samples for Histopathology 196 20.2 Fixation 196 20.3 Practical Guidelines to Optimize Fixation 199 21 Infectious Disease Testing 201 21.1 Test Types 201 21.2 Aerobic Culture 201 21.3 Anaerobic Culture 202 21.4 Fungal Culture 203 21.5 Fluorescent Antibody Tests 204 21.6 Pcr 204 21.7 Elisa 204 21.8 Virus Isolation 204 21.9 Fecal Examination 205 21.10 Immunohistochemistry 205 21.11 In Situ Hybridization 205 22 Toxicology Testing 206 23 Packaging and Shipping Samples 210 23.1 Packing Samples to Send to the Lab 211 Part V Special Cases 213 24 Forensic Necropsies 215 24.1 What Is a Forensic Necropsy? 215 24.2 Who Should Perform a Forensic Necropsy? 215 24.3 How Is a Forensic Necropsy Different from a Diagnostic Necropsy? 215 24.4 Before the Necropsy 216 24.5 The Forensic Necropsy Procedure 217 24.6 Forensic Necropsy Report 219 Part VI Appendices 221 Appendix 1 Normal Organ Weights (Percentage Body Weight) 223 Appendix 2 Describing Gross Lesions 233 A2. 1 Location 233 A. 2 Distribution 233 A2. 3 Number/Extent 233 A2. 4 Size/Weight 233 A2. 5 Color 233 A2. 6 Consistency 234 A2. 7 Texture 234 A2. 8 Shape 234 A2. 9 Lesion borders 234 A2. 10 Liquids 234 A2. 11 Odor 234 Appendix 3 Tissue Collection Checklists 235 Standard Set of Tissues for Histopathology 235 Additional Tissues for Histopathology, if History Warrants 235 Samples for Toxicology 236 Samples for Infectious Disease Testing 236 Abscess 236 Respiratory disease 236 Diarrhea 236 Abortion 236 Neurologic disease 236 Appendix 4 Online Resources 237 Index 239