VTNE Clinical Laboratory Procedures 3 — Questions and Answers
Question 1: What is the primary purpose of using a Romanowsky-type stain (e.g., Diff-Quik) on a blood smear?
- To detect bacteria only
- To differentiate and identify blood cell types and morphology (Correct answer)
- To measure hemoglobin concentration
- To identify antibiotic sensitivity
Correct answer: To differentiate and identify blood cell types and morphology
Romanowsky-type stains like Diff-Quik use methylene blue and eosin to distinguish and characterize leukocytes, erythrocytes, and platelets by color.
Question 2: In urinalysis, the presence of bilirubin in a cat's urine is considered:
- Normal up to 3+ in cats
- Always abnormal and clinically significant (Correct answer)
- Normal only in male cats
- Only significant if accompanied by glucosuria
Correct answer: Always abnormal and clinically significant
Unlike dogs, cats have a very high renal threshold for bilirubin, so any bilirubinuria in cats is considered abnormal and clinically significant.
Question 3: Which blood chemistry panel finding is most consistent with Addison's disease (hypoadrenocorticism) in a dog?
- Hyperkalemia and hyponatremia (Correct answer)
- Hypokalemia and hypernatremia
- Hypoglycemia and elevated BUN only
- Hypercalcemia and hyperphosphatemia
Correct answer: Hyperkalemia and hyponatremia
Addison's disease causes decreased aldosterone, leading to sodium loss and potassium retention, resulting in hyponatremia and hyperkalemia.
Question 4: When reading a urine dipstick result for protein, which sample characteristic can cause a false-positive reaction?
- Dilute urine (SG < 1.010)
- Highly alkaline urine (pH > 8) (Correct answer)
- Presence of glucose
- Yellow-colored urine
Correct answer: Highly alkaline urine (pH > 8)
Highly alkaline urine can cause false-positive protein results on dipstick because the colorimetric reaction is pH-dependent.
Question 5: Which finding on a canine CBC is most indicative of immune-mediated hemolytic anemia (IMHA)?
- Neutropenia with toxic changes
- Spherocytes and positive Coombs test (Correct answer)
- Hypersegmented neutrophils
- Increased eosinophils with basophilia
Correct answer: Spherocytes and positive Coombs test
Spherocytes result from partial phagocytosis of antibody-coated RBCs, and a positive Coombs test confirms immune-mediated destruction.
Question 6: What is the correct technique for preparing a direct fecal smear for parasite examination?
- Mix a large amount of feces with iodine and cover with a coverslip
- Mix a small amount of feces with saline and iodine on a slide, then coverslip (Correct answer)
- Centrifuge feces with zinc sulfate before placing on slide
- Heat-fix feces on slide before staining with Gram stain
Correct answer: Mix a small amount of feces with saline and iodine on a slide, then coverslip
A thin mixture of a small fecal sample with saline (and optionally iodine) under a coverslip allows visualization of trophozoites, cysts, and eggs.
Question 7: Which electrolyte imbalance is most commonly associated with urethral obstruction in cats?
- Hyponatremia
- Hypocalcemia
- Hyperkalemia (Correct answer)
- Hypomagnesemia
Correct answer: Hyperkalemia
Urethral obstruction prevents potassium excretion, leading to life-threatening hyperkalemia that can cause cardiac arrhythmias.
VTNE Clinical Laboratory Procedures 3
What is the primary purpose of using a Romanowsky-type stain (e.g., Diff-Quik) on a blood smear?