Equine gastric ulcer syndrome (EGUS) is a common condition in horses.

1.5 litres of acid per hour is released into the horse’s stomach to help break down food, but because horses are grazing animals this acid is released constantly, even when they are not eating.

This means damage can occur in horses with a reduced food intake or on a high cereal/low forage diet. High intensity exercise can also increase pressure within the abdomen, compressing the stomach and forcing acid into vulnerable areas.

Ulcers are associated with pain normally, however signs can be subtle and may include:

● Acute or recurrent colic

● Poor appetite

● Weight loss

● Poor coat condition

● Diarrhoea

● Poor performance

● Teeth grinding/jaw clenching

● Discomfort when girthing upHowever some horses show no signs and this means that ulcers go undiagnosed.

Gastroscopy is the only accurate way to diagnose the condition: it confirms which type of mucosa is affected (squamous or glandular) and the severity of the ulcers.


A gastroscope is a flexible tube with a camera and light on the end which allows the inside of the stomach to be seen.After sedation the gastroscope is passed up your horse’s nose and into the oesophagus.It then passes into the horse’s stomach where the vet can examine for signs of ulcers.In order for the vet to do this procedure the horse needs to have had no food from the night before and no water for the 4 hours before the vet’s arrival.

Ulcers cover a range of severities and are graded on a scoring system up to five. Grade two and above being considered clinically important. If your horse is diagnosed with ulcers your vet will discuss the best course of treatment: your vet may also advise a course of medication to help the ulcers heal and reduce acid levels in the stomach.
Prevention This may include management changes relating to diet, turnout, exercise and stress.

Simple tips that can help include:

● Making sure your horse has as much turnout as possible.

● Allowing your horse access to roughage at all times if it is stabled. Roughage requires more chewing and this chewing stimulates the production of saliva, this in turn helps to neutralize the stomach acid.

● Feeding a double handful of chaff 30 minutes before you ride (this acts like a sponge to soak up the acid).

● Avoiding stress when travelling and at competitions.

● Not feeding huge amounts of cereals.

● Adding oil to feed as a form of calories.


Veterinary advice in this magazine is provided as a general guide and you should always seek professional advice