Consider Digestive Health When Medicating Horses

Veterinarians have medications for nearly any problem that ails horses. Unfortunately, some of the most prescribed and useful medications have unwanted side effects.

“Morphine provides an excellent example of this double-edge sword, as highlighted in a recent study* conducted by French veterinary researchers,” shared Laura Petroski-Rose, B.V.M.S., a Kentucky Equine Research veterinarian. “Morphine provides effective and cost-conscious pain relief in horses but can cause decreased gastrointestinal motility, decreased fecal output, and a fourfold increase in the risk of colic.”

The researchers concluded that “systemic morphine administration causes gastrointestinal depression, gastric distension, and hyperphagia (abnormally increased appetite) in horses” and that “horses receiving systemic morphine administration should be closely monitored for signs of gastric distension and, specifically, the amount of food given while receiving treatment should be controlled to avoid complications.”

Petroski-Rose noted, “Systemic morphine administration may not be particularly common in day-to-day equine practice; however, this study points out that the delicate constitution of the horse’s gastrointestinal system can easily be disturbed by medications.”

Phenylbutazone provides a great example of the good, bad, and ugly associated with prescription medications. Widely referred to as bute, this medication offers anti-inflammatory relief but can also cause gastric ulcers, diarrhea due to right dorsal colitis, and irreversible kidney damage.

“Be certain to discuss your horse’s diet with your veterinarian whenever any medication is prescribed, and ask whether targeted nutritional support of digestive health may be warranted,” advised Petroski-Rose.

*Tessier, C., J.P. Pitaud, C. Thorin, and G. Touzot-Jourde. 2019. Systemic morphine administration causes gastric distension and hyperphagia in healthy horses. Equine Veterinary Journal 51(5):653-657.