# Phenylbutazone for Animals: Mechanism, Doses by Species & Brands

> Phenylbutazone (“bute”) is a pyrazolone NSAID available as tablets, paste, gel and injection. In horses the Equipalazone label gives 8.8 mg/kg on day 1, 4.4 mg/kg a day for four days, then…

- Source page: https://wevet.in/active-ingredients/phenylbutazone/
- Type: Active ingredient
- Publisher: WeVet
- Updated: 2026-11-02
- Medically reviewed by: Dr. Ravi Baraiya, B.V.Sc. (2026-11-02)
- Audience: veterinarians and veterinary students

Phenylbutazone (“bute”) is a pyrazolone NSAID available as tablets, paste, gel and injection [1]. In horses the Equipalazone label gives 8.8 mg/kg on day 1, 4.4 mg/kg a day for four days, then 2.2 mg/kg a day or on alternate days [2]; treated horses may never be slaughtered for food [2].

- Class: Non-steroidal anti-inflammatory drug (NSAID, pyrazolone)
- Brands: Equipalazone

## Dose by species

| Species | Use | Dose | Route | How often | Basis |
|---|---|---|---|---|---|
| Horses | Day 1 (Equipalazone: two 1 g sachets twice on day 1 for a 450 kg horse.) | 8.8 mg/kg [2] | PO | Split in two doses | Label |
| Horses | Days 2–5 | 4.4 mg/kg [2] | PO | Split in two doses · 4 days | Label |
| Horses | Maintenance (Stop if no response after 4–5 days.) | 2.2 mg/kg [2] | PO | Once daily or on alternate days | Label |
| Dogs | Pain and inflammation | 3–7 mg/kg [1] | PO | Every 8 hours | Reference |

## Uses

- Horses and ponies: lameness from osteoarthritis, laminitis, bursitis and carpitis [2].
- Dogs: reference dose in the Merck Veterinary Manual [1].

## Mechanism of action

NSAIDs reduce prostaglandin production by inhibiting the cyclooxygenase (COX) enzymes [1].

## Safety

- Its therapeutic index is low — do not exceed the dose or the duration [2].
- Do not use in animals with heart, liver or kidney disease, gut ulceration or bleeding, or blood dyscrasia, or within 24 hours of another NSAID [2].
- Treated horses may never be slaughtered for human consumption [2].


## Frequently asked questions

### Can horses treated with bute go for meat?

No — the Equipalazone SPC says treated horses may never be slaughtered for human consumption [2].

## References

[1] Nonsteroidal Anti-inflammatory Drugs in Animals — Merck Veterinary Manual — S. H. Edwards (updated Sep 2024) (2024). https://www.merckvetmanual.com/pharmacology/inflammation/nonsteroidal-anti-inflammatory-drugs-in-animals
[2] Equipalazone 1 g oral powder for horses and ponies — SPC — UK Veterinary Medicines Directorate — Dechra SPC (2026). https://www.vmd.defra.gov.uk/ProductInformationDatabase/files/SPC_Documents/SPC_1200428.PDF

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Numbers in [brackets] cite the references above. For veterinary professionals. Information supports — never replaces — clinical judgement; always check the current product label and local regulations.
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