Gastric Ulcer Syndrome in Horses: Causes, Symptoms & Treatment

What Are Gastric Ulcers?

When ulcers are discovered on the stomach lining it is referred to as gastric or stomach ulcers. Horses can commonly experience ulcers and most will suffer from this condition at some point in their lives with a greater risk for athletic horses due to increased gastric acid production and decreased blood flow to the GI tract caused by excessive exercise.

Horses have smaller stomachs compared to other animals and because of this, they will opt to eat less but more frequently throughout the day. For horses that naturally graze this also means that their body will produce a steady supply of gastric acid in order to help with digestion although the feed and saliva will dilute this acid. In situations where the horse is fed twice a day such as during boarding, this acid can instead be over-produced and affect other parts of the digestive system leading to gastric ulcers.

What Are The Causes of Gastric Ulcer Syndrome in Horses?

Gastric Ulcer Syndrome in horses is generally caused by an imbalance between mucosal aggressive and protective factors. Prolonged exposure to hydrochloric acid, pepsin, bile or organic acids may lead to ulcers in the esophagus. When a horse experiences ulcers in this area it can be compared to Gastroesophageal Reflux Disease Syndrome (GERDS) in humans. 

The length of time that the horse experiences acid exposure will determine the severity of this condition. Ulcers that occur in the glandular mucosa of horses are typically caused by a disruption of blood flow and decreased mucus and bicarbonate secretion.

If a horse has been fasting or gone through long periods without eating it will be more likely to experience gastric ulcer syndrome along with foals that nurse or feed infrequently.

What Are The Symptoms Of Gastric Ulcer Syndrome in Horses?

The majority of horses with gastric ulcers do not show outward clinical signs and can appear completely healthy. Some of the signs may include: