Gastric Ulcers are common in the equine population, effecting 37% of leisure horses in the United Kingdom. This figure increases to 63% in performance horses and as much as 93% of racehorses that may suffer from the condition within their career. 

Ulcers are caused by the over production of acid in the stomach, the most common place to see ulceration is around the margo plicatus, a line that separates the glandular and non glandular regions of the stomach. These kind of ulcers are commonly caused by splashing of the stomach acid up onto the unprotected non glandular region during intense exercise, making it common in racehorses and sports horses. They are also often caused by the stomach being empty for long periods of time, causing the stomach acid to attack the stomach lining. it also may be because feed changes the pH levels and can form a cap over the gastric contents.

The symptoms of gastric ulcers can make it difficult to pinpoint the problem as they are often seen as subtle changes in condition or behaviour symptoms include:

  • Reduced appetite 

  • Loss of condition

  • Poor performance

  • Changes in behaviour

  • Discomfort around the girth area 

EGUS is a serious condition and if you suspect your horse may be suffering from ulcers, please call your vet for an accurate diagnosis. 

Ulcers are diagnosed through gastric endoscopy, where a vet will insert a camera into the stomach to study its lining. The severity of ulceration is graded from 0-4, with grade 0 showing no sign of ulceration and grade 4 showing extensive deep tissue ulceration. Only grades 2 and above are considered significant and in need of treatment.

For a horse with gastric ulcers the correct diet is essential for managing the condition. it should be a high forage, low cereal diet with feeds being given little and often to give a trickle feeding effect. 

Forage is important for horses with gastric ulcers, it is important that it is fed ad-lib so the stomach is never left empty for long periods of time. Horses are naturally designed to be trickle feeders, if the stomach is left empty, the stomach acid can start to attack the stomach lining. Fibre in the form of hay or haylage is best as it requires more chewing. Horses only produce saliva whilst chewing, saliva is alkaline, having a high pH, so works as a buffer neutralising the stomach acid and reducing the acidity of the stomach. This keeps the pH of the stomach balanced at a healthy level. 

Diets high in starch should be avoided as they can lead to higher levels of fermentation in the stomach. Increased fermentation causes a more acidic environment and the potential build up of gas in the stomach, increasing a horses’ risk of gastric ulcers.

Steam extruded feeds, such as the feeds made here at Keyflow are more digestible so feeding rates are lower, making it easier to feed little and often, which would benefit a horse suffering from ulcers.

Stressful situations should be limited for horses with EGUS as stress is suggested to aggravate the condition. A natural lifestyle where the horse is kept at grass in a herd community is often seen as a positive way of reducing stress in horses. 

Horses with ulcers need careful management through diet and medication to control their condition. If you would like any further advice on how Keyflow can help design a diet specific to your horses needs get in touch on 01672 51 9000 or email at