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Phenylbutazone

Prescription
NSAID (Pyrazolone)
Last reviewed 21 Apr 2026 · PetCare.AI Editorial Team
Species
Dog, Cat
Brands
1 available
Interactions
1 documented
Formulations
3

Mechanism of action

Non-selective COX-1 and COX-2 inhibitor with potent anti-inflammatory, analgesic, and antipyretic properties. One of the most potent veterinary NSAIDs but with significant toxicity concerns — primarily used in horses; limited use in dogs.

At a glance

Class
NSAID (Pyrazolone)
Schedule
Prescription
Storage
Store at room temperature, protect from light

Dosing

🐕

Dog

VERY narrow safety margin in dogs — severe GI ulceration and bone marrow suppres
Dose
3–7 mg/kg
Route
PO
Frequency
q8h initially then reduce
🐈

Cat

NEVER use in cats
Dose
—
Route
N, A
Frequency
N/A

Formulations

💊

Other — 3

Strength
—
Strength
—
Strength
—

Storage

Store at room temperature, protect from light

Safety

Monitoring parameters

CBC every 3–5 days during useGI signs (melena, vomiting)Hepatic and renal functionLimit duration

Interactions

Contraindicated — 1

Prednisolone
contraindicated
Phenylbutazone (highest GI toxicity of all NSAIDs) + corticosteroid: extremely high risk of fatal GI perforation.
Management: NEVER combine. Phenylbutazone already has a very narrow safety margin — adding steroid is extremely dangerous.

Brands

Other markets

Butazolidin

FAQs

Frequently asked questions

›What is Phenylbutazone?
Phenylbutazone is a nsaid (pyrazolone) used in pets. Non-selective COX-1 and COX-2 inhibitor with potent anti-inflammatory, analgesic, and antipyretic properties. One of the most potent veterinary NSAIDs but with significant toxicity concerns — primarily used in horses; limited use in dogs.
›What is Phenylbutazone used for in pets?
Phenylbutazone is used in veterinary medicine for: VERY narrow safety margin in dogs — severe GI ulceration and bone marrow suppres; NEVER use in cats.
›What is the Phenylbutazone dose for dogs?
For dogs, Phenylbutazone is typically dosed as follows — VERY narrow safety margin in dogs — severe GI ulceration and bone marrow suppres: 3–7 mg/kg PO q8h initially then reduce. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
›What is the Phenylbutazone dose for cats?
For cats, Phenylbutazone is typically dosed as follows — NEVER use in cats: undefined undefined N/A N/A. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
›Does Phenylbutazone need a prescription?
Yes. Phenylbutazone is a prescription medication and should only be administered under veterinary supervision.

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 →

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