Necropsy Guide for Dogs, Cats, and Small Mammals

Sean P. McDonough, DVM, PhD, Diplomate ACVP, is an Associate Professor at Cornell University's College of Veterinary Medicine in Ithaca, New York, USA.

Teresa Southard, DVM, PhD, Diplomate ACVP, is an Assistant Clinical Professor at Cornell University's College of Veterinary Medicine in Ithaca, New York, USA.

List of Contributors xv

Foreword xvii

Acknowledgments xix

About the Companion Website xxi

Part I Necropsy Fundamentals 1

1 Introduction to the Necropsy 3
Sean P. McDonough and Teresa Southard

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 9
Sean P. McDonough and Teresa Southard

2.1 Necropsy Facilities 9

2.2 Necropsy Equipment 9

2.3 Safety Considerations 13

2.3.1 Cuts and Punctures 14

2.3.2 Zoonotic Disease 14

2.3.3 Formalin 15

2.4 The Importance of a Good History 15

2.5 The Necropsy Report 15

2.5.1 Gross Description 15

2.5.2 Gross Findings 16

2.5.3 Gross Diagnosis 16

2.5.4 Comment 16

2.6 Postmortem Changes 16

3 The Necropsy Procedure 21
Sean P. McDonough and Teresa Southard

3.1 Introduction 21

3.2 Weigh the Body 21

3.3 External Examination 21

3.4 Reflect the Skin and Right Limbs 22

3.5 Open the Abdominal Cavity 26

3.6 Puncture the Diaphragm 27

3.7 Open the Thoracic Cavity 27

3.8 Open the Pericardium 28

3.9 In Situ Examination of Organs 29

3.10 Remove the Adrenal Glands 30

3.11 Remove the Pluck 30

3.12 Remove the Gastrointestinal Tract, Liver, and Spleen 32

3.13 Remove the Urogenital Organs 34

3.14 Remove the Head 35

3.15 Take Out the Eyes 35

3.16 Remove the Brain 36

3.17 Remove the Pituitary Gland 37

Bibliography 37

Part II Organ Systems 39

4 The Integumentary System 41
Jeanine Peters-Kennedy

4.1 Anatomy Review 41

4.1.1 External Ear Canal Anatomy 42

4.2 In Situ Examination and Removal 42

4.2.1 Primary Lesions 42

4.2.2 Lesions that May Be Primary or Secondary 43

4.2.3 Secondary Skin Lesions 43

4.3 Organ Examination, Sectioning, and Fixation 44

4.3.1 Cytology 44

4.3.2 Skin Scrapes 44

4.3.3 Hair Examination (Trichogram) 44

4.3.4 Examination of the External Ear Canal 44

4.3.5 Sampling the Skin 45

4.4 Common Artifacts and Postmortem Changes 46

Bibliography 46

5 The Musculoskeletal System 49
Teresa Southard

5.1 Anatomy Review 49

5.1.1 Bones and Joints 49

5.1.2 Teeth 51

5.1.3 Skeletal Muscle 52

5.2 In Situ Evaluation, Sectioning, and Fixation 52

5.2.1 Bones 52

5.2.2 Joints, Tendons, and Ligaments 54

5.2.3 Skeletal Muscle 55

5.3 Special Techniques 55

5.3.1 Postmortem Imaging 55

5.3.2 Cleaning Bones 56

5.3.3 India Ink Evaluation of Articular Cartilage 56

5.3.4 Examining the Intervertebral Discs 56

5.3.5 Submitting Muscle for Additional Tests 56

5.4 Common Artifacts and Postmortem Changes 56

Bibliography 57

6 The Cardiovascular System 59
Kathleen M. Kelly

6.1 Anatomy Review 59

6.1.1 Right Heart 59

6.1.2 Left Heart 60

6.1.3 Vessels: Great and Small 60

6.1.4 Contextual Cardiac Embryology and Congenital Heart Malformations 62

6.2 In Situ Evaluation and Removal 63

6.3 Organ Examination, Sectioning, and Fixation 64

6.4 Common Artifacts, Non-lesions, and Postmortem Changes 66

Bibliography 68

7 The Respiratory System 69
Elizabeth L. Buckles and Teresa Southard

7.1 Anatomy Review 69

7.2 In Situ Evaluation and Removal 71

7.3 Organ Examination, Sectioning, and Fixation 72

7.3.1 Larynx and Trachea 72

7.3.2 Lungs 73

7.3.3 Nasal Cavity and Sinuses 74

7.4 Special Techniques 74

7.5 Common Artifacts and Postmortem Changes 75

Bibliography 75

8 The Alimentary System 77
Gerald E. Duhamel

8.1 Anatomy Review 77

8.1.1 The Oropharyngeal Cavity 77

8.1.2 The Salivary Glands 78

8.1.3 The Esophagus 78

8.1.4 The Stomach 79

8.1.5 The Small Intestine 79

8.1.6 The Large Intestine 81

8.1.7 The Intestinal Vasculature and Nervous System 82

8.2 In Situ Evaluation and Removal 82

8.2.1 The Esophagus 83

8.2.2 The Gastrointestinal Tract 83

8.3 Organ Examination, Sectioning, and Fixation 85

8.3.1 Gastrointestinal Tract 85

8.4 Special Techniques 87

8.5 Common Artifacts and Postmortem Changes 88

Bibliography 89

9 The Liver and Pancreas 91
Sean P. McDonough

9.1 Anatomy Review 91

9.1.1 The Liver 91

9.1.2 The Pancreas 93

9.2 In Situ Evaluation and Removal 94

9.2.1 The Liver 94

9.2.2 The Pancreas 96

9.3 Organ Examination, Sectioning, and Fixation 96

9.3.1 The Liver 96

9.3.2 The Pancreas 98

9.4 Common Artifacts and Postmortem Changes 98

9.4.1 The Liver 98

9.4.2 The Pancreas 99

Bibliography 99

10 The Urogenital System 101
Teresa Southard

10.1 Anatomy Review 101

10.2 In Situ Evaluation and Removal 103

10.3 Organ Examination, Sectioning, and Fixation 103

10.3.1 Kidneys 103

10.3.2 Ureters 104

10.3.3 Bladder and Urethra 104

10.3.4 Ovaries 105

10.3.5 Oviduct/Uterus/Cervix/Vagina 105

10.3.6 Testes/Epididymides/Ductus Deferens 105

10.3.7 Prostate Gland 105

10.3.8 Bulbourethral Gland (Cats Only) 106

10.3.9 Distal Colon/Rectum/Anus 106

10.4 Special Techniques 106

10.5 Common Artifacts and Postmortem Changes 106

Bibliography 106

11 The Nervous System 107
Andrew D. Miller

11.1 Anatomy Review 107

11.2 In Situ Evaluation and Removal 108

11.2.1 Brain 108

11.2.2 Spinal Cord 109

11.2.3 Peripheral Nerves 110

11.3 Organ Examination, Sectioning, and Fixation 110

11.3.1 Brain 110

11.3.2 Spinal Cord 112

11.3.3 Nerves 112

11.4 Common Artifacts and Postmortem Changes 112

Bibliography 113

12 The Eye and Ear 115
Sean P. McDonough

12.1 The Eye 115

12.1.1 Anatomy Review 115

12.1.2 In Situ Evaluation and Removal 115

12.1.3 Examination, Sectioning, and Fixation 117

12.2 The Ear 119

12.2.1 Anatomy Review 119

12.2.2 In Situ Evaluation and Removal 122

12.2.3 Examination, Sectioning, and Fixation 122

Bibliography 123

13 The Endocrine System 125
Sean P. McDonough

13.1 Anatomy Review 125

13.1.1 The Pituitary Gland 125

13.1.2 The Thyroid and Parathyroid Glands 125

13.1.3 The Endocrine Pancreas (Islets of Langerhans) 126

13.1.4 The Adrenal Glands 126

13.2 In Situ Evaluation and Removal 127

13.2.1 The Pituitary Gland 127

13.2.2 The Thyroid and Parathyroid Glands 128

13.2.3 The Endocrine Pancreas 129

13.2.4 The Adrenal Glands 130

13.3 Organ Examination, Sectioning, and Fixation 130

13.3.1 The Pituitary Gland 130

13.3.2 The Thyroid and Parathyroid Glands 131

13.3.3 The Endocrine Pancreas 131

13.3.4 The Adrenal Glands 131

13.4 Common Artifacts and Postmortem Changes 132

14 The Lymphoreticular System 133
Sean P. McDonough

14.1 Anatomy Review 133

14.1.1 Thymus 133

14.1.2 Lymph Nodes 133

14.1.3 Spleen 133

14.1.4 Bone Marrow 135

14.2 In Situ Evaluation and Removal 135

14.2.1 Thymus 135

14.2.2 Lymph Nodes 136

14.2.3 Spleen 136

14.2.4 Bone Marrow 138

14.3 Organ Examination, Sectioning, and Fixation 138

14.3.1 Thymus 138

14.3.2 Lymph Nodes 138

14.3.3 Spleen 140

14.3.4 Bone Marrow 140

14.4 Incidental Findings 141

Part III Special Cases 143

15 Small Mammal Necropsies 145
Teresa Southard

15.1 Species Differences 145

15.2 Necropsy Technique 145

Bibliography 151

16 Fetuses and Neonatal Animals 153
Teresa Southard

16.1 Anatomy 153

16.1.1 Placenta 153

16.1.2 Umbilical Cord 153

16.1.3 Fetal Circulation 153

16.2 Necropsy Technique 154

16.3 Common Artifacts and Postmortem Changes 156

Part IV Additional Testing 157

17 Cytology 159
Teresa Southard

17.1 Types of Cytology Preparations 159

17.2 Making a Touch Imprint 159

17.3 Making a Bone Marrow Smear 159

17.4 Other Preparations 160

17.5 Staining 160

17.6 Atlas of Normal Tissues 161

18 Histopathology 165
Sean P. McDonough and Teresa Southard

18.1 Necropsy Samples for Histopathology 165

18.2 Fixation 165

18.3 Practical Guidelines to Optimize Fixation 168

19 Infectious Disease Testing 171
Teresa Southard

19.1 Test Types 171

19.2 Aerobic Culture 171

19.3 Anaerobic Culture 173

19.4 Fungal Culture 173

19.5 Fluorescent Antibody Tests 174

19.6 PCR 174

19.7 ELISA 174

19.8 Virus Isolation 174

19.9 Qualitative Fecal 174

19.10 Immunohistochemistry 174

20 Toxicology Testing 175
Teresa Southard

Bibliography 175

21 Packaging and Shipping Samples 179
Sean P. McDonough

21.1 Packing Samples to Send to the Lab 180

Bibliography 180

Appendix 1: Normal Organ Weights (Percentage Body Weight) 183

Appendix 2: North American Diagnostic Laboratories 187

Appendix 3: Tissue Collection Checklist 193

Appendix 4: Describing Gross Lesions 195

Index 197