DVM Clinical Pathology and Diagnostics 5 — Questions and Answers
Question 1: A dog has a prolonged APTT with a normal PT. Which coagulation factor deficiency is most consistent with this pattern?
- Factor VII deficiency
- Factor VIII deficiency (hemophilia A) (Correct answer)
- Factor X deficiency
- Vitamin K deficiency
Correct answer: Factor VIII deficiency (hemophilia A)
Factor VIII is part of the intrinsic pathway (measured by APTT only), so its deficiency prolongs APTT while PT remains normal.
Question 2: A dog's serum biochemistry shows a markedly elevated GGT with mild ALT elevation. Which condition is most associated with this pattern in dogs?
- Acute hepatocellular necrosis
- Biliary disease or cholestasis (Correct answer)
- Muscle trauma
- Renal tubular damage
Correct answer: Biliary disease or cholestasis
GGT is a sensitive marker of cholestasis and biliary disease in dogs; marked elevation with modest ALT suggests primary biliary rather than hepatocellular pathology.
Question 3: A feline tracheal wash yields a smear with many eosinophils and Curschmann's spirals. What condition does this suggest?
- Bacterial pneumonia
- Feline asthma (allergic bronchitis) (Correct answer)
- Lungworm infection
- Pulmonary carcinoma
Correct answer: Feline asthma (allergic bronchitis)
Eosinophilic airway inflammation with Curschmann's spirals (mucus plugs from small airways) is characteristic of feline allergic bronchitis (asthma).
Question 4: On urinalysis of a dog with suspected diabetes mellitus, which combination of findings is most expected?
- USG 1.050, glucosuria, ketonuria, proteinuria (Correct answer)
- USG 1.005, glucosuria, bilirubinuria
- USG 1.035, hematuria, bacteriuria
- USG 1.010, cylindruria, no glucosuria
Correct answer: USG 1.050, glucosuria, ketonuria, proteinuria
Uncontrolled diabetes mellitus causes glucosuria and, in ketoacidosis, ketonuria; USG is often high due to glucosuria acting as an osmotic agent.
Question 5: A dog has a serum calcium of 14.5 mg/dL and a PTH-rP level that is markedly elevated. What is the most likely diagnosis?
- Primary hyperparathyroidism
- Hypoadrenocorticism
- Humoral hypercalcemia of malignancy (Correct answer)
- Vitamin D toxicosis
Correct answer: Humoral hypercalcemia of malignancy
PTH-related protein (PTH-rP) is secreted by neoplasms (commonly anal sac apocrine gland adenocarcinoma and lymphoma) and is the leading cause of humoral hypercalcemia of malignancy.
Question 6: Which reticulocyte response indicates adequate regeneration following acute hemorrhage in a dog?
- Absolute reticulocyte count >60,000/µL
- Absolute reticulocyte count >80,000/µL (Correct answer)
- Reticulocyte percentage >0.5%
- Any polychromasia on smear
Correct answer: Absolute reticulocyte count >80,000/µL
An absolute reticulocyte count above 80,000/µL is generally considered indicative of an adequate regenerative response in dogs.
Question 7: A horse has pleural fluid analysis showing a cloudy yellow effusion with total protein 5.0 g/dL, nucleated cells 25,000/µL, and intracellular bacteria on cytology. What is the diagnosis?
- Chylothorax
- Transudative heart failure
- Septic pleuritis (pleuropneumonia) (Correct answer)
- Hemothorax
Correct answer: Septic pleuritis (pleuropneumonia)
High protein, markedly elevated neutrophil counts, and intracellular bacteria in equine pleural fluid confirm septic pleuritis, most often due to Streptococcus or Pasteurella spp.
DVM Clinical Pathology and Diagnostics 5
A dog has a prolonged APTT with a normal PT.
Which coagulation factor deficiency is most consistent with this pattern?