Table of Contents

Contributors xi


Preface xiii


1 General Laboratory Medicine 3
Raquel M. Walton


General laboratory medicine 3


Basic hematologic techniques 4


Point-of-care testing 6


Test validation and reference values 10


References 14


2 Equine Hematology 15
Raquel M. Walton


Complete blood count interpretation 15


Erythrocyte indices 15


Leukogram 20


Platelets 22


Blood film evaluation 23


Erythrocytes and platelets 25


Leukocytes 30


References 33


3 Immunohematology and Hemostasis 37
Karen V. Jackson


Immunohematology testing 39


Blood typing 39


Crossmatching 41


Antibody screening and jaundiced foal agglutination test 42


Immune-mediated hemolytic anemia 44


Neonatal isoerythrolysis 46


Infection-associated (Clostridial, EIA, R. equi, S. equi) 48


Drug-associated 50


Neoplasia-associated 50


Coagulation testing 51


Physiology of hemostasis 51


Coagulation testing and disorders causing abnormalities 60


References 66


4 The Liver 71
Dennis J. Meyer and Raquel M. Walton


Liver enzymes 71


Hepatocellular enzymes 73


Hepatobiliary enzymes 74


Liver function tests 76


Excretory function tests 76


Tests dependent on synthetic/metabolic functions 77


Other tests 79


Hepatic diseases 80


Toxins 80


Infections 82


Hepatic lipidosis 83


Serum hepatitis (Theiler’s disease) 83


Hepatocellular neoplasia 84


References 84


5 Laboratory Evaluation of the Equine Renal System 87
Andrea A. Bohn


Laboratory assessment of the kidney 87


Glomerular filtration rate 89


Reabsorption and electrolyte regulation 90


Water conservation and blood volume regulation 91


Other renal functions 92


Urinalysis 92


Gross evaluation 92


Urine-specific gravity 92


Reagent test strips 94


Urine sediment exam 95


Laboratory abnormalities associated with different disease states 98


Acute renal failure 98


Chronic renal failure 98


Urinary tract rupture 99


“Early” renal disease 100


Strenuous exercise 101


References 101


6 Acid-Base and Electrolytes 103
Andrea A. Bohn


Acid-base 103


Steps to evaluating acid-base status 104


Bicarbonate 104


Metabolic acidosis and alkalosis 105


Respiratory acidosis and alkalosis 106


Compensatory mechanisms 106


Base excess 107


Electrolytes 107


Sodium 107


Chloride 109


Potassium 110


Calcium 112


Magnesium 114


Phosphate 115


References 116


7 Proteins 119
Koranda Wallace


Plasma proteins 119


Albumin 119


Globulin 120


Acute phase proteins 120


Protein disorders 124


Hypoalbuminemia with hypoglobulinemia 124


Hypoalbuminemia with normal or increased globulins 125


Hypoglobulinemia with normal to increased albumin 125


Hyperalbuminemia 126


Hyperalbuminemia and hyperglobulinemia 126


Hyperglobulinemia 126


Hyperfibrinogenemia 127


References 127


8 Laboratory Assessment of Lipid and Glucose Metabolism 131
Raquel M. Walton


Lipids 131


Triglyceride metabolism 132


Laboratory characterization of lipid metabolism 133


Equine hyperlipidemias 136


Glucose 138


Glucose metabolism 139


Insulin resistance 140


Laboratory characterization of glucose metabolism 140


Diseases associated with glucose metabolic defects 145


References 149


9 Skeletal Muscle 153
Allison Billings


Laboratory evaluation of equine muscle disorders 153


General causes of increased serum enzymes 153


Serum enzymes detecting muscle injury 154


Additional factors affecting CK and AST enzyme activity 158


Other markers detecting muscle injury 159


Equine muscle diseases 161


Immune-mediated myopathies 161


Infectious myopathies 163


Traumatic myopathies 165


Inherited or congenital myopathies 166


Toxic myopathies 169


Nutritional myopathies 171


Myopathies of unknown cause 171


Other myopathies 173


References 173


10 Endocrine Evaluation 181
Jill Beech


Testing for pituitary pars intermedia dysfunction (PPID) 181


Cortisol concentrations 182


Adrenocorticotropin (ACTH) concentration 184


Alpha-melanocyte-stimulating hormone (α-MSH) concentrations 186


ACTH and α-MSH concentration responses following thyrotropin releasing hormone (TRH) administration 186


Insulin concentrations 187


Testing thyroid function in horses 189


Thyroid dysfunction 189


Thyroid hormones 189


Extrathyroidal effects on thyroid hormones 190


Nonthyroidal illness syndrome 192


Thyroid hormone evaluation 192


Thyroid stimulating hormone (TSH) concentration 193


Thyrotropin releasing hormone (TRH) stimulation 194


TSH stimulation test 194


T3 suppression test 195


References 195


11 Fluid Analysis 203
Raquel M. Walton


Pleural and peritoneal fluid 203


Pathogenetic mechanisms of body cavity effusions 204


Body cavity fluid analysis 208


Biochemical evaluation 210


Cells and cell counts 212


Synovial fluid 218


Fluid analysis 219


Degenerative arthropathies 224


Inflammatory arthropathies 225


Eosinophilic synovitis 227


Hemarthrosis 227


References 229


12 Cytology of the Lower Respiratory Tract 233
Martina Piviani


Indications 233


Collection techniques 234


Bronchoalveolar lavage 234


Tracheal wash 234


Sample processing 235


Normal findings 236


Cellular elements 236


Acellular elements 239


Contaminants 240


Interpretation of cytologic patterns 241


Neutrophilic inflammation 241


Mixed neutrophilic and histiocytic inflammation 245


Eosinophilic and mastocytic inflammation 245


Hemosiderosis 246


Cellular atypia 248


References 249


13 Cerebrospinal Fluid 253
Andrea Siegel


Formation, circulation, absorption, and function 253


Collection 254


Laboratory analysis 254


Gross appearance 255


Protein concentration 256


Antibody titers 258


Cell counts 258


Glucose 260


Enzymes 260


Lactic acid 260


Polymerase chain reaction 261


Phenotyping 261


Cytological examination 261


Normal findings 262


Abnormal findings 263


CSF in specific diseases 264


Viral infections 264


Bacterial infections 265


Fungal infections 265


Parasitic infections 266


Other diseases 266


References 266


Index 271

About the Author

Raquel M. Walton, VMD, MS, PhD, is a senior ClinicalPathologist at the Animal Medical Center in New York, New York.

Reviews

Overall, this book should be very useful to student andequine practitioners. (Doody s, 24October 2014) The material provided in this book is well written andsupported by adequate numbers of photomicrographs, diagrams, andcharts. While the intended target audience is wide, this bookappears to be particularly appropriate for senior veterinarystudents, clinical pathology residents, and equinepractitioners. Clinical pathologists and equine specialistswill find this text to be a helpful adjunct to their referencelibrary. (Veterinary Clinical Pathology, 16October 2014)