AAVSB Clinical Pathology and Laboratory Diagnostics 2 — Questions and Answers
Question 1: Which coagulation test specifically evaluates the extrinsic and common pathways?
- Activated clotting time (ACT)
- Prothrombin time (PT) (Correct answer)
- Activated partial thromboplastin time (aPTT)
- Platelet count
Correct answer: Prothrombin time (PT)
PT measures the time for clot formation via the extrinsic pathway (factor VII) and common pathway (factors X, V, II, I).
Question 2: A cat presents with marked thrombocytopenia (platelets 12,000/µL). Which clinical sign is most expected?
- Deep tissue hematomas
- Petechiae and ecchymoses (Correct answer)
- Prolonged PT with normal aPTT
- Lymphadenopathy
Correct answer: Petechiae and ecchymoses
Severe thrombocytopenia impairs primary hemostasis, leading to petechiae and mucosal bleeding rather than deep hemorrhage.
Question 3: A dog with parvovirus has a WBC of 1,200/µL with 80% neutrophils and a left shift. How is this finding classified?
- Neutrophilia with degenerative left shift
- Neutropenia with degenerative left shift (Correct answer)
- Neutrophilia with regenerative left shift
- Leukocytosis with bandemia
Correct answer: Neutropenia with degenerative left shift
Neutropenia with a degenerative left shift (more bands than segs) reflects overwhelming demand exceeding bone marrow production, common in parvovirus.
Question 4: Which fecal flotation solution has the highest specific gravity and is best for recovering most parasite ova?
- Sheather's sugar solution (SG 1.27) (Correct answer)
- Zinc sulfate solution (SG 1.18)
- Sodium nitrate solution (SG 1.20)
- Saturated sodium chloride (SG 1.20)
Correct answer: Sheather's sugar solution (SG 1.27)
Sheather's sugar solution (SG ~1.27) has the highest specific gravity, allowing recovery of a broader range of eggs including heavy ones.
Question 5: A bovine blood sample shows packed cell volume (PCV) of 12% and plasma that appears pink. What does the pink plasma indicate?
- Lipemia from a recent meal
- Intravascular hemolysis releasing free hemoglobin (Correct answer)
- Icterus from biliary obstruction
- Hypoproteinemia
Correct answer: Intravascular hemolysis releasing free hemoglobin
Pink (hemolyzed) plasma combined with severe anemia points to intravascular hemolysis and free hemoglobin release into circulation.
Question 6: Which test is considered the gold standard for diagnosing feline hyperthyroidism?
- Free T4 by equilibrium dialysis
- Total T4 (TT4) (Correct answer)
- TSH stimulation test
- Nuclear scintigraphy
Correct answer: Total T4 (TT4)
Total T4 is the initial screening test of choice for feline hyperthyroidism due to its high sensitivity in overtly hyperthyroid cats.
AAVSB Clinical Pathology and Laboratory Diagnostics 2
Which coagulation test specifically evaluates the extrinsic and common pathways?