What causes gastric ulcers?

Stress is a major risk factor for ulcers. Physical and environmental stressors such as intense exercise, stall confinement, and transport stress are common in horses and increase the risk of your horse developing gastric ulcers.

Avoid stressful situations when possible and talk with your veterinarian about using Equestra as a preventative option during transport and competition.

Stress is a major risk factor for equine gastric ulcers

Other risk factors

Feeding (fewer meals per day)

In their natural state, horses are constantly grazing for up to 16 hours a day. A horses stomach has evolved to constantly secrete acid to begin breaking down this feed. As a horse grazes, a constant flow of saliva helps to buffer the stomach acid.

When we remove access to constant feed and grazing, and the horse goes for prolonged periods between feeds, the horse’s stomach continues to secrete acid. With no feed or saliva to assist with buffering the constant acid production, the excess acid can lead to ulceration.


Horses that are fed diets high in sugar and starch (such as high-grain diets) have an increased risk for ulcer development. Starches are rapidly fermented and cause the stomach environment to be even more acidic.

Grains (both textured and pelleted) do not require as much chewing as forages and less saliva is produced. So not only do the grains produce a more acidic stomach environment than forages, but they also reduce the amount of saliva available to help buffer the acid.

Abrupt changes to a horse’s diet can cause stress and lead to digestive upset, which can in turn increase the risk of ulcers.

Training and Competing

Duration and intensity of training or competing increases the prevalence and severity of ulcers in the non-glandular squamous region of the stomach. During strenuous exercise the horse’s stomach is compressed, forcing the acidic contents upwards. This creates “acid splash” and acid-mediated injury to the unprotected, non-glandular part of the stomach.


Excessive use of non-steroidal anti-inflammatory drugs (NSAIDs) such as bute-phenylbutazone (Bute) and banamineflunixin megalumine (Flunixin) as well as the misuse of many other medications are known to increase the risk of ulcers.


Horses are social animals. Social stressors like changes in the herd group or changes to the environment, feed or routine can cause stress in the horse.

Being herd animals, a lack of daily visual and direct horse-to-horse contact will contribute to stress in the horse. 

Equestra Equine Omeprazole administration is stress free for the horse.

This supports the objective of minimising stress on the horse, helping to improve the horse’s general health as well as optimising the clinical outcomes of treatment.

One could say that syringe alternatives are perhaps counter-intuitive, in that administration of syringed pastes can be a stressful ordeal for all involved.

Back to Top