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Thiamine (Vitamin B1)

Water-Soluble Vitamin / Neurological Support
Last reviewed 21 Apr 2026 · PetCare.AI Editorial Team
Species
Dog, Cat
Brands
2 available
Formulations
3

Mechanism of action

Essential cofactor for pyruvate dehydrogenase, alpha-ketoglutarate dehydrogenase, and transketolase — key enzymes in glucose metabolism and the pentose phosphate pathway. Deficiency causes polioencephalomalacia (PEM) and Wernicke's encephalopathy.

At a glance

Class
Water-Soluble Vitamin / Neurological Support
Schedule
OTC
Storage
Store at room temperature; protect from light; injectable stable at room temperature

Dosing

🐕

Dog

Thiamine deficiency from raw fish diet (thiaminase enzyme), sulfite preservative
Dose
10–20 mg/kg
Route
IV, IM, SQ, PO
Frequency
q24h
🐈

Cat

Thiamine deficiency more common in cats fed raw fish diet or canned fish heavy d
Dose
50–250 mg/cat
Route
IV, IM, PO
Frequency
q24h

Formulations

💊

Other — 3

Strength
Strength
Strength

Storage

Store at room temperature; protect from light; injectable stable at room temperature

Safety

Monitoring parameters

Neurological improvement within 24–48h of treatmentDietary history correctionSerum thiamine levels if available

Interactions

No documented interactions.

Brands

Other markets

Thiamine HCl
Betaxin

FAQs

Frequently asked questions

What is Thiamine (Vitamin B1)?
Thiamine (Vitamin B1) is a water-soluble vitamin / neurological support used in pets. Essential cofactor for pyruvate dehydrogenase, alpha-ketoglutarate dehydrogenase, and transketolase — key enzymes in glucose metabolism and the pentose phosphate pathway. Deficiency causes polioencephalomalacia (PEM) and Wernicke's encephalopathy.
What is Thiamine (Vitamin B1) used for in pets?
Thiamine (Vitamin B1) is used in veterinary medicine for: Thiamine deficiency from raw fish diet (thiaminase enzyme), sulfite preservative; Thiamine deficiency more common in cats fed raw fish diet or canned fish heavy d.
What is the Thiamine (Vitamin B1) dose for dogs?
For dogs, Thiamine (Vitamin B1) is typically dosed as follows — Thiamine deficiency from raw fish diet (thiaminase enzyme), sulfite preservative: 10–20 mg/kg IV/IM/SQ/PO q24h. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
What is the Thiamine (Vitamin B1) dose for cats?
For cats, Thiamine (Vitamin B1) is typically dosed as follows — Thiamine deficiency more common in cats fed raw fish diet or canned fish heavy d: 50–250 mg/cat IV/IM/PO q24h. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
Does Thiamine (Vitamin B1) need a prescription?
Thiamine (Vitamin B1) is available over the counter. Even so, you should consult your veterinarian before giving any medication to your pet.

References

References

Textbooks & handbooks

  • Plumb, D.C. Plumb's Veterinary Drug Handbook. 10th ed., Wiley-Blackwell, 2023.
  • Vail, D.M., Thamm, D.H., & Liptak, J.M. (eds.). Withrow & MacEwen's Small Animal Clinical Oncology. 6th ed., Saunders/Elsevier, 2020.
  • Riviere, J.E., & Papich, M.G. (eds.). Veterinary Pharmacology and Therapeutics. 10th ed., Wiley-Blackwell, 2018.
  • National Research Council. Nutrient Requirements of Dogs and Cats. National Academies Press, Washington DC, 2006.
  • The Merck Veterinary Manual. Merck & Co., Online edition. https://www.merckvetmanual.com/

Clinical guidelines & consensus

  • Fletcher, D.J., Boller, M., Brainard, B.M., et al. "RECOVER Evidence and Knowledge Gap Analysis on Veterinary CPR." Journal of Veterinary Emergency and Critical Care, 2012;22(S1):S102–S131.
  • American Animal Hospital Association. 2018 AAHA Diabetes Management Guidelines for Dogs and Cats. AAHA Press.

Journals & peer-reviewed studies

  • Hogan, D.F., Fox, P.R., Jacob, K., et al. "Secondary prevention of cardiogenic arterial thromboembolism in the cat: The FAT CAT study." Journal of Veterinary Cardiology, 2015;17(Suppl 1):S306–S317.
  • Boswood, A., Häggström, J., Gordon, S.G., et al. "Effect of Pimobendan in Dogs with Preclinical Myxomatous Mitral Valve Disease and Cardiomegaly: The EPIC Study — A Randomized Clinical Trial." Journal of Veterinary Internal Medicine, 2016;30(6):1765–1779.
  • ASPCA Animal Poison Control Center. Toxicology and Poison Management Guidelines. American Society for the Prevention of Cruelty to Animals. https://www.aspca.org/pet-care/animal-poison-control

Regulatory & approvals

  • Central Drugs Standard Control Organisation (CDSCO), Government of India. Veterinary Drug Approval Registry, 1969–2026. Directorate General of Health Services. https://cdsco.gov.in/

Databases

  • Washington State University, College of Veterinary Medicine. Veterinary Clinical Pharmacology Laboratory (VCPL) — MDR1 Multidrug Sensitivity Database. https://vcpl.vetmed.wsu.edu/
Educational reference only
This information is provided for educational purposes and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a qualified veterinarian before administering any medication to your pet. Find a vet near you →