Small Animal Medical Differential Diagnosis

• PART ONE: CLINICAL SIGNS APPROACH TO DIFFERENTIAL DIAGNOSIS

• Abdominal Distension

Abdominal Effusions and Ascites

Abdominal Pain, Acute

Aggressive Behavior

Alopecia

Anaphylaxis

Anuria and Oliguria

Anxiety and Phobias

Ascites

Ataxia and Incoordination

Blindness

Bradycardia, Sinus

Cachexia and Muscle Wasting

Compulsive Behavior Disorders

Constipation

Coughing

Cyanosis

Deafness

Diarrhea, Acute

Diarrhea, Chronic

Dyschezia

Dysphagia

Dyspnea

Dysuria

Ecchymoses

Edema

Epistaxis

Failure to Grow/Failure to Thrive

Fever of Unknown Origin

Flatulence

Gagging

Genital dermatoses - NEW!

Halitosis

Head Tilt

Hematemesis

Hematochezia

Hematuria

Hemoptysis

Hemorrhage, Prolonged

Horners Syndrome

Hyperpigmentation (increased melanin in the epidermis) - NEW!

Hyperthermia

Hypopigmentation (due to melanocyte destruction, dysfunction, or abnormal distribution of melanosomes) - NEW!

Hypothermia

Icterus (Jaundice)

Inappropriate Elimination

Incontinence, Fecal

Incontinence, Urinary

Infertility, Female (Canine)

Infertility, Male (Canine)

Joint Swelling

Lameness

Lymphadenopathy (Lymph Node Enlargement)

Melena

Muscle Wasting

Nasal Discharge

Nystagmus

Obesity

Oliguria

Pallor

Papules and Pustules

Paresis and Paralysis

Petechiae and Ecchymoses

Pollakiuria

Polyuria and Polydipsia

Pruritus

Ptyalism (Excessive Salivation)

Regurgitation

Reverse Sneezing - NEW!

Scaling and Crusting - NEW!

Seizure

Sneezing and Nasal Discharge

Stertor and Stridor

Stranguria, Dysuria, and Pollakiuria

Stomatitis

Stupor and Coma

Syncope

Tachycardia, Sinus

Tenesmus and Dyschezia

Tremor

Urine, Discolored

Urticaria/Angioedema

Vision Loss, Sudden

Vomiting

Weakness

Weight Gain

Weight Loss

PART TWO: SYSTEMIC APPROACH TO DIFFERENTIAL DIAGNOSIS

Section I

Cardiopulmonary Disorders

Arrhythmias

Aspiration Pneumonia- NEW!

Atrioventricular Valve Disease, Chronic (Mitral or Tricuspid Valve)

Cardiomegaly

Chylothorax - NEW!

Congenital Heart Disease

Heart Failure

Heartworm Disease

Hypertension

Laryngeal and Pharyngeal Disease

Lower Respiratory Tract Disease

Mediastinal Disease

Myocardial Diseases

Murmurs

Pericardial Effusion

Pleural Effusion

Pulmonary Disease

Pulmonary Edema

Pulmonary Thromboembolism

Tachycardia, Sinus

Section II

Dermatologic Disorders

Allergic Skin Disease

Alopecia, Endocrine

Erosions and Ulcerations of Skin or Mucous Membranes - NEW!

Folliculitis

Otitis Externa, Chronic

Parasitic Dermatoses

Pigmentation

Pyoderma

Section III

Endocrinologic and Metabolic Disorders

Acromegaly

Adrenal Tumors

Cretinism (Hypothyroidism in Puppies)

Diabetes Insipidus

Diabetic Ketoacidosis

Diabetes Mellitus

Gastrinoma (Zollinger-Ellison Syndrome)

Glucagonoma

Hyperadrenocorticism

Hyperglycemia

Hypoadrenocorticism

Hypoglycemia

Hyponatremia/Hyperkalemia

Insulinoma

Parathyroidism

Pheochromocytoma

Pituitary Dwarfism

Thyroid Disease

Section IV

Gastroenterologic Disorders

Chronic Constipation, Feline - NEW!

Diarrhea

Dental and Oral Cavity Diseases

Diseases of the Tongue - NEW!

Salivary Gland Disease

Esophageal Disease

Stomach Disorders

Small Intestinal Disease

Large Intestinal Disease

Ileus

Malabsorptive Diseases

Perianal Disease

Protein-Losing Enteropathy

Fecal Incontinence

Section V

Hematologic Disorders

Anemia

Coagulopathies, Inherited and Acquired

Leukocyte Disorders

Platelet Dysfunction

Splenitis/Splenomegaly

Thrombocytopenia

Section VI

Immunologic and Immune-Mediated Disorders

Autoimmune Skin Diseases

Immune-Mediated Disease

Immune System Components

Mechanisms of Immunopathologic Injury - NEW!

Organ Systems Affected by Autoimmune Disorders in the Dog and Cat -- NEW!

Systemic Lupus Erythematosus (SLE)

Section VII

Infectious Disease

Anaplasmosis, Canine - NEW!

Bacterial Infections, Systemic

Ehrlichiosis, Canine

Influenza, Canine - NEW!

Neorickettsiosis, Canine

Mycoses, Systemic - NEW!

Polysystemic Protozoal Diseases

Rocky Mountain Spotted Fever

Sepsis and Systemic Inflammatory Response Syndrome (SIRS)

Vaccines, Recommended Core vs. Non-Core - NEW!

Viruses, Canine

Viruses, Feline

Section VIII

Joint and Bone Disorders

Arthritis

Bone Disorders

Section IX

Liver and Exocrine Pancreatic Disorders

Cholangitis and Cholangiohepatitis, Feline

Exocrine Pancreatic Disease

Gallbladder and Extrahepatic Biliary Disease

Hepatic Encephalopathy

Hepatic Lipidosis, Feline

Hepatobiliary Disease

Hepatomegaly and Microhepatica

Hyperlipidemia

Pancreatitis

Portosystemic Shunt, Congenital

Vacuolar Hepatopathy, Canine

Section X

Neoplasia

Chemotherapeutic Agent Toxicity

Corticosteroid Therapy

Humoral Hypercalcemia - NEW!

Histiocytic Disease

Lymphoma

Paraneoplastic Syndromes

Sarcomas

Thyroid Neoplasms

Tumors

Section XI

Neurologic and Neuromuscular Disorders

Brain Disease, Congenital or Hereditary

Cognitive Dysfunction

Cranial Nerve (CN) Deficits

Head Tilt

Inflammatory Disease of the Nervous System

Intracranial Neoplasms

Myasthenia Gravis

Myositis and Myopathies

Neurologic Examination

Paroxysmal Disorders Confused with Epileptic Seizures - NEW!

Peripheral Neuropathies

Spinal Cord Disease

Spinal Cord Lesions

Systemic Disease

Vestibular Disease

Section XII

Ocular Disorders

Anisocoria - NEW!

Blindness, Acute

Corneal Color Changes - NEW!

Eyelids and Periocular Skin - NEW!

Non-healing Corneal Erosions (Ulcers) in Dogs - NEW!

Ocular Manifestations of Systemic Diseases

Ocular Neoplasia - NEW!

Red Eye - NEW!

Retinal Detachment - NEW!

Uveitis - NEW!

Section XIII

Toxicology

Chemical Toxicoses

Plant Toxicoses

Venomous Bites and Stings

Section XIV

Urogenital Disorders

Differentiating between urine marking and inappropriate elimination in cats - NEW!

Glomerular Disease

Indications for Cytoscopy - NEW!

Mammary Masses - NEW!

Prostatic Disease

Proteinuria in Dogs and Cats - NEW!

Pyelonephritis, BacterialRenal Disease

Reproductive Disorders

Ureteral Diseases

Urinary Tract Infection (UTI)

Uroliths, Canine

Vaginal Discharge

Section XV

Pain Diagnosis - NEW!

Acute Pain Assessment - NEW!

Acute Pain Preemptive Scoring System (examples in each category) - NEW!

Chronic Pain Assessment - NEW!

PART THREE: LABORATORY VALUES AND INTERPRETATION OF RESULTS

Acetylcholine Receptor Antibody

Activated Coagulation Time (ACT)

Activated Partial Thromboplastin Time (APTT)

Adrenocorticotropic Hormone (ACTH), Endogenous

Adrenocorticotropic Hormone (ACTH) Stimulation Test

Alanine Aminotransferase (ALT, formerly SGPT)

Albumin

Alkaline Phosphatase, Serum (SAP or ALP)

Ammonia

Amylase, Serum

Anion Gap

Antinuclear Antibody (ANA)

Arterial Blood Gases

Aspartate Aminotransferase (AST, formerly SGOT)

Basophil Count

Bicarbonate (HCO₃^-)

Bile Acids

Bilirubin

Blood Urea Nitrogen (BUN)

Buccal Mucosal Bleeding Time (BMBT)

Calcium (Ca)

Cerebrospinal Fluid (CSF)

Chloride (Cl)

Cholesterol (CH)

Cholinesterase

Cobalamin

Complete Blood Count (CBC)

Coombs Test

Cortisol

Creatine Kinase (CK, f NEW!ormerly CPK)

Creatinine

Cytologic Criteria of Malignancy - NEW!

Cytologic Features of Discrete Cell (Round Cell) Tumors - NEW!

Cytologic Features of Mesenchymal Cells - NEW!

Cytologic Features of Normal Epithelial Cells - NEW!

Cytology of Ear Canal Swabs - NEW!

Cytology of Nasal Swabs or Flush Specimens - NEW!

Dexamethasone Suppression Tests

Disseminated Intravascular Coagulation (DIC), Diagnostic Tests

Eosinophil Count

Erythrocyte Count (Red Blood Cell [RBC] Count)

Folate

Fructosamine

Gamma Glutamyltransferase (GGT)

Globulin, p. xx

Glucose

Glucose Tolerance Test

Glycosylated Hemoglobin

Heartworm Antibody, Feline

Heartworm Antigen, Canine

Heartworm Antigen, Feline

Hematocrit (Packed Cell Volume, PCV)

Hemoglobin

Hemolysis, Prevention in Laboratory Samples

Immunoassays

Insulin

Iron-Binding Capacity (Total, TIBC)/Ferritin

Joint Fluid (Arthrocentesis)

Lipase

Lymphocyte Count

Magnesium (Mg)

Mean Corpuscular Volume (MCV)

Methemoglobinemia

Methods of Sample Collection for Cytology

Monocyte Count

Myoglobinuria

Neutrophil Count

Osmolality

Packed Cell Volume

Parathyroid Hormone (PTH)/Ionized Calcium

Phosphorus (P)

Platelet Count

Polymerase Chain Reaction, p. xx - NEW!

Potassium (K)

Protein, Total (TP)

Prothrombin Time (PT)

Red Blood Cell (RBC) Count

Reticulocyte Count

Sodium (Na)

Thoracocentesis Fluid

Thrombocyte Count

Thyroid Function Tests

Toxoplasmosis Antibody Titer

Triglycerides

Trypsinogen-like Immunoreactivity (TLI)/Pancreatic Lipase Immunoreactivity (PLI)

Urinalysis

Urine Cortisol/Creatinine Ratio

von Willebrands Factor

White Blood Cell (WBC) Count

Index