BCSE BCSE - Basic and Clinical Sciences Examination Clinical Nutrition and Metabolism Questions and Answers 2 — Questions and Answers
Question 1: Ruminant grass tetany (hypomagnesemic tetany) occurs primarily due to which mechanism?
- Rapid grass growth in spring produces low-magnesium forage, and ruminants cannot mobilize bone magnesium stores efficiently (Correct answer)
- Excess dietary calcium blocking magnesium absorption
- Renal magnesium wasting caused by high potassium intake
- Primary CNS magnesium depletion independent of diet
Correct answer: Rapid grass growth in spring produces low-magnesium forage, and ruminants cannot mobilize bone magnesium stores efficiently
Lush spring pastures are low in magnesium and high in potassium, which inhibits Mg absorption; cattle and sheep cannot mobilize skeletal Mg reserves rapidly enough.
Question 2: What is the recommended dietary protein level (% dry matter) for healthy adult maintenance in dogs according to AAFCO guidelines?
- 18% dry matter minimum (Correct answer)
- 10% dry matter minimum
- 30% dry matter minimum
- 25% dry matter minimum
Correct answer: 18% dry matter minimum
AAFCO sets the minimum dietary protein at 18% dry matter for adult dog maintenance, with 22.5% required for growth and reproduction.
Question 3: Hepatic lipidosis in cats most commonly develops secondary to which condition?
- Prolonged anorexia causing peripheral fat mobilization that overwhelms hepatic VLDL export capacity (Correct answer)
- High-fat diet feeding
- Chronic low-grade hepatitis
- Primary bile duct obstruction
Correct answer: Prolonged anorexia causing peripheral fat mobilization that overwhelms hepatic VLDL export capacity
Feline hepatic lipidosis results when anorexia triggers massive lipolysis; cats have limited capacity to export fat as VLDL, leading to triglyceride accumulation in hepatocytes.
Question 4: Which fatty acid is classified as omega-3 and is an essential dietary nutrient that cannot be synthesized de novo by mammals?
- Alpha-linolenic acid (ALA) (Correct answer)
- Oleic acid
- Palmitoleic acid
- Arachidonic acid
Correct answer: Alpha-linolenic acid (ALA)
Alpha-linolenic acid (18:3n-3) is an essential omega-3 fatty acid because mammals lack the delta-15 desaturase needed to introduce the n-3 double bond.
Question 5: Urease-producing gut bacteria in ruminants allow utilization of non-protein nitrogen (NPN) such as urea because they:
- Convert urea to ammonia, which rumen microbes incorporate into microbial protein (Correct answer)
- Directly synthesize essential amino acids from urea carbon skeletons
- Ferment urea to volatile fatty acids for energy
- Transport urea directly across the rumen wall
Correct answer: Convert urea to ammonia, which rumen microbes incorporate into microbial protein
Rumen microorganisms use urease to hydrolyze urea to ammonia, which they then incorporate into microbial protein that is subsequently digested in the abomasum.
Question 6: A horse with equine metabolic syndrome (EMS) typically shows which metabolic abnormality as the primary feature?
- Peripheral insulin dysregulation (hyperinsulinemia and insulin resistance) (Correct answer)
- Hypothyroidism with low T4
- Primary hypercortisolism (PPID/Cushing's)
- Hyperlipidemia from chronic starvation
Correct answer: Peripheral insulin dysregulation (hyperinsulinemia and insulin resistance)
EMS is characterized by regional adiposity, hyperinsulinemia, and insulin resistance that predisposes affected horses to pasture-associated laminitis.
BCSE BCSE - Basic and Clinical Sciences Examination Clinical Nutrition and Metabolism Questions and Answers 2
Ruminant grass tetany (hypomagnesemic tetany) occurs primarily due to which mechanism?