title: Ulcerative cystitis associated with phenylbutazone administration in two horses.
abstract: METHODS
  A 15-year-old Quarter Horse gelding and a 26-year-old Thoroughbred gelding were evaluated because of hematuria of 4 to 6 days' duration following prolonged oral administration of phenylbutazone.
  
  
  RESULTS
  The horses had received either treatment with phenylbutazone for 3 months or intermittent long-term phenylbutazone treatment prior to development of hematuria. Each horse was systemically stable but had orthopedic or neurologic problems. Clinicopathologic findings included normochromic normocytic anemia in both horses and hypoalbuminemia and high BUN concentration in 1 horse. In both horses, urinalysis revealed proteinuria and RBCs, but no evidence of WBCs or bacteria. Ulceration and hemorrhage of the urinary bladder with no evidence of uroliths were observed via cystoscopy. Gastric ulceration along the margo plicatus was observed via gastroscopy.
  
  
  RESULTS
  For each horse, phenylbutazone treatment was discontinued and a synthetic prostaglandin (misoprostol) was administered. The hematuria resolved, and results of a follow-up CBC, serum biochemical analysis, urinalysis, and cystoscopy 25 or 30 days after cessation of phenylbutazone treatment were unremarkable in both cases.
  
  
  CONCLUSIONS
  Given the known adverse effects of NSAID treatment in several species, phenylbutazone and its metabolites were suspected to have caused ulceration of the urinary bladder, resulting in hematuria, in the 2 horses. A definitive cause of urinary bladder ulceration was not confirmed in these cases; however, resolution of ulceration after discontinuation of phenylbutazone treatment and administration of synthetic prostaglandins and exclusion of other causes suggested an association between phenylbutazone administration and ulcerative cystitis in these horses.
authors.affiliation: William R. Pritchard Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California-Davis, Davis, CA 95616, USA. mraleman@ucdavis.edu
authors.forename: Monica
authors.initials: M
authors.lastname: Aleman
authors.forename: Jorge E
authors.initials: JE
authors.lastname: Nieto
authors.forename: Jamie K
authors.initials: JK
authors.lastname: Higgins
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000009:adverse effects*; D000897:Anti-Ulcer Agents / Q000627:therapeutic use; D003556:Cystitis / Q000139:chemically induced / Q000662:veterinary*; D006417:Hematuria / Q000139:chemically induced / Q000662:veterinary*; D006734:Horse Diseases / Q000139:chemically induced*; D006736:Horses; D008297:Male; D016595:Misoprostol / Q000627:therapeutic use; D009853:Omeprazole / Q000627:therapeutic use; D010653:Phenylbutazone / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use; D014456:Ulcer / Q000139:chemically induced / Q000188:drug therapy / Q000662:veterinary
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D000897:Anti-Ulcer Agents; D016595:Misoprostol; D010653:Phenylbutazone; D009853:Omeprazole