Phenylbutazone toxicosis in the horse: a clinical study.

The research examines the effects of the drug phenylbutazone on horses and finds that there are negative complications, such as anorexia and weight loss, when given in doses greater than 8.8 mg/kg of body weight per day.

Study Methodology and Sample

• The research was a retrospective study that means it looked at past cases rather than conducting a new, hands-on experiment.
• The authors examined 269 cases of horses that had been treated with a drug called phenylbutazone.

Results of Phenylbutazone Administration

• No major side effects were observed among horses receiving a small dose of phenylbutazone (less than or equal to 8.8 mg/kg of body weight/day for less than or equal to 4 days.)
• Horses could also handle a slightly larger dose (2 to 4 mg/kg of body weight/day) administered for a prolonged period (up to 50 days) without any clinical abnormalities.

Negative Effects of Higher Doses

• Horses that were given a higher dose (greater than 8.8 mg/kg of body weight/day) suffered several complications.
• The complications ranged from loss of appetite, depression, colic and protein deficiency to diarrhea, bloody stool, weight loss and swelling in the lower body.
• Some horses demonstrated signs of internal bleeding, such as speckled hemorrhages on the mucous membranes.
• Serious complications included erosions and ulcers in the mouth and gastrointestinal tract, damage to the kidney tissue, and in some cases even death.

Signs of Gastrointestinal-related Shock

• In two cases, horses showed symptoms suggestive of a severe, potentially fatal medical condition called gastrointestinal-related shock, likely caused by the large doses of phenylbutazone.

Conclusions

• This study concludes that phenylbutazone can have various negative effects on horses if given in doses greater than 8.8 mg/kg of body weight per day, including major health complications and potentially death.
• It serves as a caution for veterinary practitioners on the administration of phenylbutazone, suggesting the importance of careful dosing to prevent serious health issues in horses.