Vitamin B1 (Thiamine) Deficiency in Cats

Thiamine deficiency is a rare and life-threatening condition that causes serious neurological symptoms. Vitamin B1 deficiency is easily treatable with immediate medical attention. If treatment is delayed, the animal may suffer from prolonged neurological abnormalities.

Symptoms of vitamin B1 deficiency can take weeks to months to appear, depending on the underlying cause. In the early stages of vitamin B1 deficiency, the cat may present with vomiting and decreased appetite. Both of these early symptoms increase the effect of the deficiency.

If left untreated, the animal progresses to the neurological phase of the deficiency, with symptoms increasing in severity, including seizures and coma.

Early treatment of thiamine deficiency is crucial. If the deficiency enters the neurological phase, the animal may suffer from long-term neurological impairments even after treatment.

Diets at risk of causing vitamin B1 deficiency include:

• All-fish diets: fish contains an anti-nutrient enzyme (thiaminase) that renders thiamine nonfunctional
• All-meat diets
• Commercial diets: despite recommended standards, commercial processed cat food does not always contain sufficient amounts of thiamine
• Cooked diets: cooking and overheating diets destroys thiamine

Animal nutrition is complex and is further complicated by widespread food trends which are not always aligned with current medical consensus. Consulting with a veterinarian or veterinary nutritionist is often the best way to ensure an individual pet’s needs are fully met.

Vitamin B1 deficiency is caused by low thiamine in the diet.

Other causes include:

• Severe hepatic disease
• Intestinal disease or surgical removal of sections of the intestines causing malabsorption of nutrients
• Starvation
• Diuretic medication administration or kidney diseases
• Administration of the medication pyrimethamine

Thiamine deficiency is a rare condition in cats. It is difficult to diagnose. Ruling out other causes of symptoms is the first step in diagnosis.

In general, diagnostic strategies for symptoms of thiamine deficiency include:

• Discussion of dietary history
• Physical examination
• Blood tests
• Urinalysis
• Diagnostic imaging such as ultrasound or X-rays
• Testing clinical response to thiamine administration

Once diagnosed, treatment options include:

• Thiamine administration (IV or oral)
• Dietary modification to an appropriately supplemented diet

If treated early, prognosis for thiamine deficiency is very good, with most animals responding to treatment within 24-48 hours.

If treatment is delayed, the cat can suffer from long-term neurological symptoms, even after treatment has concluded.

If left untreated, thiamine deficiency is life-threatening.

Vitamin B1 deficiency is not contagious. The most effective way to prevent thiamine deficiency is to feed a healthy and balanced diet.

Thiamine deficiency is a rare condition in cats. Cats on all-meat or all-fish diets are at higher risk of developing thiamine deficiency.

• Thiamine administration (IV or oral)
• Dietary modification