BCSE - Basic and Clinical Sciences Examination Clinical Nutrition and Metabolism Questions and Answers Flashcards

Which vitamin deficiency causes 'rickets' in young animals, and what is the biochemical mechanism?

Answer: Vitamin D deficiency impairs intestinal calcium and phosphorus absorption, preventing normal bone mineralization

Vitamin D (as 1,25-dihydroxycholecalciferol) upregulates intestinal calcium-binding protein; deficiency reduces Ca/P absorption, leaving osteoid unmineralized.

Body condition scoring (BCS) in dogs uses which scale and what score indicates ideal body condition?

Answer: 1–9 scale; a score of 4–5 indicates ideal condition

The Purina/WSAVA 9-point BCS system for dogs rates 4–5 as ideal, where ribs are easily palpable with minimal fat cover and a waist is visible.

The B vitamin thiamine (B1) deficiency in cats fed exclusively raw fish can cause which neurological syndrome?

Answer: Polioencephalomalacia (cerebrocortical necrosis) due to impaired pyruvate dehydrogenase activity

Raw fish contains thiaminase that destroys dietary thiamine; without thiamine, pyruvate dehydrogenase fails, impairing CNS glucose metabolism and causing cerebrocortical necrosis.

In calculating ruminant energy rations, which unit system is used to express energy requirements and feed energy values?

Answer: Net energy (NE) expressed in megacalories (Mcal), subdivided into NE for maintenance (NEm), gain (NEg), and lactation (NEl)

Ruminant ration balancing uses net energy subdivisions (NEm, NEg, NEl) in Mcal because different physiologic processes use available energy with different efficiencies.

Which trace mineral deficiency in cattle causes 'falling disease' (sudden cardiac failure) and depigmentation of the hair coat?

Answer: Copper deficiency

Copper deficiency impairs cytochrome c oxidase in cardiac muscle (causing heart failure) and tyrosinase activity (causing hair depigmentation and sunbleached coat).

A cat presenting with posterior paresis and cervical ventroflexion should raise clinical suspicion for deficiency of which nutrient?

Answer: Thiamine (vitamin B1)

Cervical ventroflexion with posterior weakness is a classic presentation of thiamine deficiency in cats, arising from thiaminase ingestion or inadequate dietary intake.