Ulcerative cystitis associated with phenylbutazone administration in two horses.

The research article analyzes the effects of a prolonged oral administration of phenylbutazone on two horses, a 15-year-old Quarter Horse gelding and a 26-year-old Thoroughbred gelding. The article suggests that the medication may have led to ulcerative cystitis in the horses, causing them to pass bloody urine.

Introduction and Background

• The issue in focus is the occurrence of hematuria – presence of bloody urine in the two horses. This issue arose following a prolonged oral administration of a non-steroidal anti-inflammatory drug (NSAID) called phenylbutazone. The duration of the treatment was either 3 months of continuous use or intermittent long-term administration.
• The two horses were otherwise systemically stable, meaning their overall bodily functions were normal. However, they had orthopedic or neurologic problems. This suggests that phenylbutazone was probably administered to manage pain, inflammation, or fever associated with these issues.

Results from the Tests

• Various tests were conducted and the results included normochromic normocytic anemia (a normal size and colour, but lower number of red blood cells), hypoalbuminemia (low albumin in the blood) and high BUN (Blood Urea Nitrogen) concentration in one horse.
• The urinalysis for both horses revealed proteinuria (presence of excess proteins in the urine) and red blood cells. However, there was no evidence of white blood cells or bacteria, ruling out an infection as a cause of the symptoms.
• Cystoscopy, a procedure to view the urinary bladder, revealed ulceration and hemorrhage but no evidence of uroliths (stones in urinary track). Furthermore, a gastroscopy exam, which visualizes the upper part of the gastrointestinal tract, showed gastric ulceration.

Post-Treatment Results

• The treatment plan involved discontinuing phenylbutazone and administering a synthetic prostaglandin called misoprostol to the horses. Following this, the bloody urine problem resolved and results of follow-up tests were unremarkable, meaning they were normal or not of concern.

Conclusions

• The researchers concluded that there was a likely association between long-term phenylbutazone administration and ulcerative cystitis in the two horses. However, they acknowledge a definitive cause was not established.
• The conclusion is mainly based on the resolution of symptoms after cessation of phenylbutazone treatment, administration of synthetic prostaglandins, and upon ruling out other potential causes.