While the rigors of training, showing, stall confinement, and travel have previously been shown to increase a horse’s risk for gastric ulcers, a new study suggests that broodmares at pasture–with none of these risk factors–are likely to have ulcers as well.

The study, conducted by Sarah S. le Jeune, DVM, Dipl. ACVS, Dipl. ECVS, staff veterinarian at the University of California, Davis, revealed that 70.9% of the 62 Thoroughbred broodmares scoped had gastric ulcers. These mares had not been transported for at least two weeks prior to scoping, and all lived on the same farm under similar management.

"We know–or we thought–that pastured horses would have perfect mucosa," le Jeune said, noting the actual rate of horses affected by ulcers in this study is comparable to those in active race training.

While the overall ulcer rate in the broodmares was higher than expected, the mean grade of ulcer was 3.3 (on a scale of 1 to 5, one being least severe), which is considered mild. Only two mares had ulcers in the glandular region of the stomach (an area that is well-protected against acid damage) and these mares had poor body condition scores