Effects of large doses of phenylbutazone administration to horses.
The effects of large doses of phenylbutazone were evaluated in clinically normal horses. The drug was given to 4 groups of 2 horses each at the rate of 30 mg/kg of body weight, orally, or 30, 15, or 8 mg/kg IV daily for up to 2 weeks. All horses became anorectic and depressed after 2 to 4 phenylbutazone treatments, and the horses given 15 or 30 mg/kg died on or between days 4 and 7 of treatment. A decrease in total blood neutrophil count occurred in all horses, and was associated with toxic left shift in horses given the 2 larger dosage schedules. The horses also had progressive increases in serum urea nitrogen, creatinine, and phosphorus concentrations, accompanied by decreasing serum calcium concentrations. There was a progressive decrease in total serum protein in all 8 horses. Gastrointestinal ulcerations, renal papillary necrosis, and vascular thromboses were the predominant postmortem findings.
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000009:adverse effects; D002371:Cat Diseases / Q000139:chemically induced; D002415:Cats; D004283:Dog Diseases / Q000139:chemically induced; D004285:Dogs; D005260:Female; D005753:Gastric Mucosa / Q000187:drug effects; D005767:Gastrointestinal Diseases / Q000139:chemically induced / Q000662:veterinary*; D006734:Horse Diseases / Q000139:chemically induced*; D006736:Horses; D006801:Humans; D007413:Intestinal Mucosa / Q000187:drug effects; D007674:Kidney Diseases / Q000139:chemically induced / Q000662:veterinary*; D007681:Kidney Papillary Necrosis / Q000139:chemically induced / Q000662:veterinary; D008297:Male; D009503:Neutropenia / Q000139:chemically induced / Q000662:veterinary; D010653:Phenylbutazone / Q000008:administration & dosage / Q000009:adverse effects*; D051381:Rats; D012376:Rodent Diseases / Q000139:chemically induced; D013924:Thrombophlebitis / Q000139:chemically induced / Q000662:veterinary; D014456:Ulcer / Q000139:chemically induced / Q000662:veterinary
D000893:Anti-Inflammatory Agents; D010653:Phenylbutazone