Phenylbutazone, usually shortened to “bute,” is one of the most commonly administered non-steroidal anti-inflammatory drugs in equine medicine. Chances are, you have some bute in your tack or feed room right now. But how much do you really know about this widely used medication? Which of the following statements about bute are true and which are false?

1.  It takes 12 hours for the effects of bute to be felt by the horse.
2. Bute reduces fever.
3. Bute will cause gastric ulcers when given daily for more than three days.
4. Small doses of bute can be safely taken by people.

Answers:

1. False. Bute is absorbed quickly into the bloodstream, and the effects are usually felt by the horse within two hours. 

2. True. In addition to relieving musculoskeletal pain, bute reduces fever caused by viral or bacterial infection. Bute does not cure the infection but simply decreases the associated signs.

3. False. Bute has been implicated in the development of gastric ulcers and other digestive problems, but such complications are usually associated with overdoses or many months of daily use. Individual reactions vary, so it’s not possible to set absolute guidelines about its gastric effects. That said, it is always wise to consult with your veterinarian before giving bute to any horse and to follow the dosage guidelines on the label.

4. False. Although phenylbutazone was originally developed for human use, it was withdrawn from that market in the United States due to serious side effects, including jaundice, kidney failure and heart problems. Bute-induced comas have also been reported in human medical literature. The “safe” human dose of bute is unknown. Never take bute yourself.