Think back to the last prescription medication commercial you saw on television or heard on the radio. Chances are, the laundry list of potential side effects (most of which probably sound worse than the aliment the drug was designed to treat!) was almost as long as the promotional part of the advertisement. Equine medications’ are no different.

Omeprazole, for example, is an extremely popular medication used to both prevent and treat gastric ulcers in horses, and some horses at risk for developing ulcers receive omeprazole on a daily basis. But some studies in human medicine (doctors commonly use the drug to treat heartburn, stomach ulcers, and gastroesophageal reflux disease) have identified an association between omeprazole and decreased bone density.

“Decreased bone mineral density may put horses at risk for fracture, especially athletic horses,” explained Stephanie Caston, DVM, Dipl. ACVS, from the College of Veterinary Medicine at Iowa State University, in Ames.

Considering the widespread use of omeprazole in the horse industry and potentially disastrous consequences of suboptimal bone health, Caston and colleagues sought to find out whether the drug had the same bone-health effects on horses as it could in humans