Animal Care and Veterinary Diagnostic Imaging & Laboratory Testing 2 — Questions and Answers
Question 1: What does a complete blood count (CBC) measure in veterinary patients?
- The number and types of blood cells including erythrocytes, leukocytes, and thrombocytes (Correct answer)
- Blood glucose, electrolytes, and kidney function values only
- Clotting factor activity and coagulation times
- Hormone levels and thyroid function
Correct answer: The number and types of blood cells including erythrocytes, leukocytes, and thrombocytes
A CBC quantifies and characterizes red blood cells (erythrocytes), white blood cells (leukocytes), and platelets (thrombocytes) in a blood sample.
Question 2: Which CBC value represents the percentage of red blood cells in a whole blood sample?
- Packed cell volume (PCV) or hematocrit (Correct answer)
- Mean corpuscular volume (MCV)
- Mean corpuscular hemoglobin concentration (MCHC)
- Red cell distribution width (RDW)
Correct answer: Packed cell volume (PCV) or hematocrit
The PCV (packed cell volume), also called hematocrit, is the percentage of total blood volume occupied by red blood cells after centrifugation.
Question 3: What is the approximate normal packed cell volume (PCV) range for a healthy adult dog?
- 37–55% (Correct answer)
- 20–30%
- 60–70%
- 10–20%
Correct answer: 37–55%
Normal canine PCV ranges from 37–55%; values below this range indicate anemia, and values above suggest polycythemia or dehydration.
Question 4: An elevated alanine aminotransferase (ALT) level in a dog most specifically suggests:
- Hepatocellular damage or liver cell injury (Correct answer)
- Reduced glomerular filtration and kidney disease
- Pancreatic inflammation (pancreatitis)
- Skeletal or cardiac muscle breakdown
Correct answer: Hepatocellular damage or liver cell injury
ALT is released from damaged liver cells (hepatocytes) and is the most liver-specific enzyme in dogs, making it a key marker of hepatocellular injury.
Question 5: What does the finding of thrombocytopenia on a CBC indicate?
- A platelet count below the normal reference range, which may impair clotting and increase bleeding risk (Correct answer)
- An elevated platelet count above the normal reference range
- Abnormal platelet shape with reduced function but normal numbers
- The complete absence of all blood cell lines including platelets
Correct answer: A platelet count below the normal reference range, which may impair clotting and increase bleeding risk
Thrombocytopenia means 'too few platelets' (thrombocytes); the suffix '-penia' always indicates a deficiency, which can lead to spontaneous bleeding.
Question 6: Which two blood chemistry values are MOST commonly used to assess renal function in veterinary patients?
- Blood urea nitrogen (BUN) and creatinine (Correct answer)
- Alanine aminotransferase (ALT) and alkaline phosphatase (ALP)
- Total bilirubin and bile acids
- Amylase and lipase
Correct answer: Blood urea nitrogen (BUN) and creatinine
BUN and creatinine are the primary markers of kidney filtration function; elevations typically indicate reduced glomerular filtration rate (azotemia).
Question 7: A CBC differential showing increased band neutrophils (immature neutrophils) alongside mature neutrophilia is called a 'left shift' and most likely indicates:
- Active bacterial infection or significant systemic inflammation causing increased demand for neutrophils (Correct answer)
- A chronic allergic response with associated eosinophilia
- Viral infection causing lymphocytosis and neutropenia
- Bone marrow suppression from chemotherapy or toxin exposure
Correct answer: Active bacterial infection or significant systemic inflammation causing increased demand for neutrophils
A left shift indicates the bone marrow is releasing immature (band) neutrophils due to high demand, most commonly caused by bacterial infection or severe inflammation.
