Phenylbute Powder

Phenylbutazone (NSAID) for musculoskeletal pain, lameness, and inflammation in horses; osteoarthritis, laminitis, and navicular disease. Phenylbutazone NSAID (injectable or powder). Mechanism: non-selective COX-1 and COX-2 inhibitor → reduces prostaglandin synthesis → anti-inflammatory, analgesic, and antipyretic. Pyrazolone derivative. High protein binding; long tissue half-life in horses. Key information Phenylbutazone — see full phenylbutazone entry. IV only in horses. Do not use in food horses. Administer with feed.

Horses — IV: administer slowly into jugular vein only. Oral: mix granules into grain. Store at room temperature; protect from light. If a dose is missed Give the missed dose as soon as you remember, always with feed. Do not double the dose.

GI: gastric and right dorsal colonic ulceration (right dorsal colitis — most significant concern in horses; higher risk than other NSAIDs). Renal: acute tubular necrosis (dehydration). Oral ulceration at paste contact sites (mucous membranes). Hematologic: aplastic anemia, agranulocytosis, thrombocytopenia (rare but serious in dogs — highly toxic species for PBZ). Protein-losing enteropathy. Hepatotoxicity.

For animals Monitor for GI ulceration; use with caution in animals with GI disease. — right dorsal colonic ulceration (horses); gastric ulceration (dogs). Monitor renal function, hydration status, and urine output. Oral ulceration at mucosal contact sites (oral paste). NOT FOR USE IN CATS — severe toxicity. Not approved for use in food-producing animals. Drug interaction: highly protein-bound — displaces other protein-bound drugs. Do not use concurrently with other NSAIDs or corticosteroids. Avoid in geriatric, debilitated, or renally compromised horses. For people handling this medication Wear gloves when handling. Wash hands thoroughly with soap and water after handling. NSAID — potentially serious human health concern: aplastic anemia, agranulocytosis possible with chronic human exposure (especially through paste inhalation or skin contact). Wear gloves when handling. Keep out of reach of children. Pregnant women and women of childbearing age should avoid contact. Do not use in food animals. Keep out of reach of children. Inform your doctor if handling regularly.

Contact your veterinarian or emergency clinic immediately. Overdose causes severe GI ulceration, kidney damage, and anemia. IV support required.