Thiamine deficiency

Question 1

What is thiamine

Answer 1

Thiamine, one of the water-soluble B vitamins (B1), is required for the formation of the coenzyme thiamin pyrophosphate, which serves as a coenzyme in decarboxylation reactions in both carbohydrate and AA catabolism

Thiamine is also used in the biosynthesis of some neurotransmitters

Question 2

What are the main causes for thiamine deficiency

Answer 2

Thiamine deficiency can be seen in cats fed large amount of raw or undercooked fish diets that contain thiaminase, an enzyme that destroys thiamine
- cooking the fish destroys thiaminase and eliminates the problem

Suplhur dioxide (food additive 220, 221) in pet-mince can destroy the thiamine in vitamin supplements and commercial food thus the condition can still occur in animalls being fed a combined diet if mince is added to every meal
- owners should be advised to purchase human-grade meat that does not contain preservatives if mince is to be included as a regular part of the cat’s diet

Question 3

What are the lesions associated with thiamine deficiency

Answer 3

Thiamine deficiency causes hemorrhagic necrosis of the oculomotor and vestibular nuclei, the caudal colliculus and the lateral geniculate nucleus due to the high thiamine requirements of these areas of the brain

Myocardial degeneration has also been associated with thiamine deficiency

Question 4

What are the clinical signs associated with thiamine deficiency

Answer 4

Early signs include:
- anorexia
- vomiting
- bilateral vestibular dysfunction
- cervical ventroflexion

As the disease progresses:
- bilateral mydriasis
- blindness
- seizure
- coma
- eventually death

In some cases, seizures may be the only clinical manifestation