Phenylbutazone ("Bute")

What is this medication for?

• Musculoskeletal pain/inflammation (OA, laminitis), colic adjunct (anti-endotoxic), pleuropneumonia pyrexia
• Pyrexia/anti-inflammatory (legacy)
• Historical — superseded by safer approved NSAIDs (Plumb: "little reason to use today")

How is it given?

Give exactly as your veterinarian prescribed — never change the dose or stop on your own unless your veterinarian has told you to.

What if I miss a dose?

• Give it as soon as you remember — unless it is almost time for the next dose (then skip the missed one; never double up).
• Call your clinic if you miss more than one dose in a row.

Side effects — what should I watch for?

Effects listed as common in this handout

• Right dorsal colitis (Chronic-use entity)
• Overdose: colic, loss of appetite, wobbliness/unsteadiness; fluid retention complicates fluid therapy (APCC profile)

Worth a phone call to your veterinarian

• stomach/intestinal ulcers, sodium/water retention, renal flow ↓, marrow effects (Canine profile (legacy))

⚠️ Contact your veterinarian or an emergency clinic IMMEDIATELY if you notice

• stomach/intestinal/oral erosions-ulcers, hypoalbuminemia, diarrhea, loss of appetite, renal papillary tissue death (The equine toxicity set (esp. overdose/dehydration/ponies))

Before starting (or refilling), tell your veterinarian if your pet:

• has or has had: Hypersensitivity; hematologic/marrow disease; stomach/intestinal ulcers; food-producing animals (FDA-prohibited extra-label — residue enforcement)
• has or has had: Foals/ponies, renal disease, CHF, dehydration

• is pregnant, nursing, or used for breeding
• is taking any other medications, supplements, or flea/tick products, including:
  • Other NSAIDs (flunixin/firocoxib)
  • Anticoagulants (warfarin-class displacement)
  • Hepatic enzyme inducers/inhibitors

Storage and handling

into a vein slowly with care; paste/powder/tablet oral forms.

Good to know

• "Bute" is equine pharmacology shorthand: OA, laminitis, colic-support for decades — now sharing ground with firocoxib (coxib-selective) but holding the laminitis-efficacy claim.
• The laminitis dosing philosophy is the pearl: intentionally under-analgesic maintenance (1–1.5 g bid) so the horse rests rather than re-traumatizes laminiae.
• Pony/foal sensitivity + hypoalbuminemia monitoring = the exam pair; food-animal prohibition = the pharmacy-law line.
• Max 4 g/day ceiling regardless of size — over that is where the ulcer/colitis stories start.