7 Benefits of Thiamine (B1) for Dogs Highlighted by Veterinarians — Key to Nerve Health

Brain & CognitionIngredientsMeongsiljang Veterinary Advisory Board

We’ve summarized the key points pet owners should know about thiamine (vitamin B1), including its benefits for nerve health, symptoms of deficiency, and recommended daily intake.

What Is Thiamine (B1)?

Thiamine (vitamin B1) is a water-soluble vitamin that acts as an essential cofactor for normal carbohydrate metabolism and plays a crucial role in maintaining healthy nerve function in dogs and cats. The key point to remember is that dogs and cats cannot produce thiamine on their own, so they must obtain it daily through their diet. Cats, in particular, are highly susceptible to deficiency, which has been classically reported in cases involving diets rich in thiamine-destroying foods like raw fish or nutritionally imbalanced meals. Furthermore, because the body stores very little thiamine, deficiency symptoms can appear more quickly than with other vitamins, making a consistent diet of balanced, complete pet food absolutely essential.

Key Effects of Thiamine

Thiamine is more than just a vitamin; it acts as the "switch" in the process by which the brain and nerves generate energy.

Supports nerve transmission: It is an essential coenzyme required for brain nerve cells to oxidize glucose (carbohydrates) and produce ATP energy.

Carbohydrate metabolism: It serves as a necessary cofactor for normal carbohydrate oxidation; a deficiency leads to elevated blood pyruvate levels.

Cardiac function: Given that cardiac abnormalities have been reported in thiamine-deficient cats, it is also linked to heart health.

Early gastrointestinal signs: In the early stages of deficiency, gastrointestinal symptoms such as loss of appetite or vomiting may appear first.

Thiamine at a Glance

Safe

티아민(Thiamine, B1)

신경·뇌 에너지 대사, 심장·소화 기능 유지

Dosage: 강아지 0.56mg/1,000kcal, 고양이 1.4mg/1,000kcal

미국국립연구위원회(NRC) 권장

Veterinary Research Evidence

According to the National Research Council’s textbook on pet nutritional requirements, thiamine exists primarily in its active form, thiamine pyrophosphate (TPP), within animal tissues, accounting for approximately 80–85% of total thiamine. TPP acts as a coenzyme that supports key enzymes in the energy (ATP) production pathway of brain neurons. When thiamine levels are insufficient, ATP production in the brain decreases, leading to impaired neuronal function. Thiamine deficiency encephalopathy in cats has been recognized since early reports by Jubb and colleagues in 1956, and prognosis is generally favorable if the condition is detected early and thiamine supplementation is promptly administered.

A veterinarian examining a dog's neurological responses

Recommended Feeding Amounts

According to the National Research Council (NRC), thiamine is an essential nutrient required daily for both dogs and cats. Cats are particularly susceptible to deficiency, which is frequently reported in cases where they consume raw fish. Feeding a balanced, complete diet that meets Association of American Feed Control Officials (AAFCO) standards typically provides adequate amounts. However, one study found that approximately 13% of commercial canned cat foods failed to meet the AAFCO minimum requirements, so it is important to be mindful of both food selection and storage. Any additional supplements should only be administered after consulting with a veterinarian.

Symptoms of Deficiency

When thiamine levels drop, the brain, nerves, and heart—the organs with the most active energy metabolism—are the first to send warning signals. Early stage (loss of appetite): Your pet may refuse food, vomit, or lose weight. Middle stage (neurological symptoms): You may notice head tremors or a posture where the neck is bent forward (abdominal flexion). Late stage (severe neurological damage): The condition can progress to seizures, gait ataxia, or coma. Cat-specific symptom: A characteristic sign in cats is the "abdominal flexion" posture, where they crouch with their head bent forward.

A pet owner checking on their cat's condition

Foods Rich in Thiamine

According to veterinary nutrition textbooks, thiamine is present in many foods, but rich sources are limited.

Yeast and malt (wheat germ): These are the natural sources with the highest concentrations.

Liver and kidney: These animal-based sources have excellent thiamine content.

Whole grains (brown rice, oats): Thiamine is abundant in the germ of unrefined grains.

Legumes (beans): These plant-based sources are rich in thiamine.

However, raw fish contains an enzyme called thiaminase that destroys thiamine. Feeding a diet primarily composed of raw fish increases the risk of deficiency. In particular, feeding cats a diet consisting solely of fish can lead to thiamine deficiency.

Situations to Watch Out For

Commercial canned fish, homemade raw fish diets, and home-cooked or canned meals that have been heated at high temperatures for extended periods increase the risk of thiamine deficiency. Thiamine is particularly heat-sensitive and can be easily destroyed when food or meat is excessively heated; in fact, cases of deficiency caused by canned foods or overcooked meat have been reported. Additionally, raw fish containing thiaminase and meat preserved with sulfur dioxide can also lead to deficiency. Cats are especially vulnerable to thiamine deficiency and may develop neurological symptoms relatively quickly, so homemade diets should always be designed in consultation with a veterinarian or veterinary nutritionist.

Reviewed by a veterinarian

Dr. Tony — Punnawat Phongkittirak

Veterinarian

A veterinarian who majored in veterinary medicine at Khon Kaen University, Thailand, and completed the IVSA program at North Carolina State University in the United States. Drawing on clinical experience at animal hospitals, he works in the pet healthcare field and is dedicated to building a digital care environment that connects pet parents with veterinarians.

Frequently Asked Questions

Is it okay to give a thiamine supplement separately?

If your pet is doing well on a complete and balanced diet that meets AAFCO standards, additional supplements are generally unnecessary. Only consider supplements when there’s a risk of deficiency—such as with a diet heavy in raw fish, homemade meals cooked at high temperatures for extended periods, or prolonged loss of appetite—and always consult your veterinarian before making any decisions.

Is it safe to consume excessive amounts of thiamine?

Thiamine is a water-soluble vitamin, so excess amounts are mostly excreted in urine, making the risk of toxicity relatively low. However, excessive supplementation has been reported to cause thiamine toxicity symptoms such as hypotension and bradycardia, so avoid administering high doses arbitrarily and stick to the recommended amount.

Why do cats need more thiamine than dogs?

As obligate carnivores, cats have specific dietary needs, and thiamine deficiency has long been recognized as a risk, particularly from raw fish containing thiaminase. Since cats store very little thiamine in their bodies, deficiency symptoms can appear quickly. Therefore, it is essential to consistently feed them a balanced, complete cat food to maintain adequate thiamine levels.

Can feeding fish frequently lead to a deficiency?

Raw fish contains an enzyme that destroys thiamine, so feeding it repeatedly can lead to a deficiency. Always cook fish before giving it to your pet (heating destroys this enzyme), and make sure their main diet consists of a complete and balanced commercial pet food for safety.

Is thiamine deficiency reversible?

In the early and middle stages of deficiency, many pets recover quickly with thiamine supplementation, as determined by their veterinarian. However, if the condition progresses to late-stage neurological damage, lasting sequelae may occur, making early detection crucial.