Does Omeprazole Reduce Cribbing in Horses?

Researchers have linked gastric issues, such as colic or ulcers, and cribbing in horses, but they’ve never confirmed if one causes the other. So, a student at Randolph College, in Lynchburg, Virginia, sought to determine if treating gastric ulcers as the cause could reduce the notoriously difficult-to-curb behavior in cribbers.

Reilly Wren presented her study findings at the 2019 Equine Science Society Symposium, held June 3-6 in Asheville, North Carolina.

One theory as to why cribbing sometimes occurs simultaneously with gastric ulcers, said Wren, is that it’s a relief mechanism for stomach discomfort. Cribbing increases saliva production, which helps buffer the stomach acid that causes painful gastric ulcers. When horses crib, they also produce β-endorphin, an opioid that not only gives them an endorphin “high” but also can provide pain relief, Wren explained.

So, in her study, she treated 15 known cribbers with either a control paste or a standard dose (1 mg/kg/day) of omeprazole (GastroGard, the only FDA-approved treatment for gastric ulcers) for 28 days. Her team did not scope the horses to confirm whether they had gastric ulcers, because their focus was on behavior changes, not ulcer resolution.

Before and after the treatment period, Wren noted each horse’s number of crib-bites and time spent cribbing. She also noted body condition score and collected blood and saliva samples to measure β-endorphin concentrations and saliva pH levels.

Wren did not find any significant behavioral or physiological changes in either the treatment or control group horses. Some owners did report improved overall behavior and a reduction in the frequency with which their horses performed other stereotypies.

As a result, said Wren, owners should not rely on this dose of omeprazole to treat cribbing.