Question of the Day

Accidental peri-vascular injection of phenylbutazone (IM, or SC) is very irritating, causing swelling, necrosis, sloughing.

Accidental intra-arterial injection of phenylbutazone can cause CNS stimulation, seizures, collapse and death in horses. 

Toxic effects of phenylbutazone include ulcerating gastroenteritis (oral cavity, stomach, and right dorsal colon) with hypoalbuminemia and diarrhea, and renal papillary crest necrosis with signs of renal failure.