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Gastric Ulcers in Horses

Gastric ulceration (Equine gastric ulceration syndrome "EGUS") is a commonly diagnosed condition in horses of any type - recent studies found that 80% of racehorses, over 60% of competition horses and up to 50% of leisure horses were affected with gastric ulcers, ranging in severity.

Gastric ulcers are formed due to excessive exposure of the stomach lining to the gastric acid of the stomach. The acidic nature of the gastric juice erodes the lining of the stomach, resulting in ulceration and bleeding in severe cases.

Symptoms are often non-specific and include:

  • Poor performance

  • Changes in temperament such as biting or kicking when brushing around the abdomen, girthing pain and resistance to riding aids

  • Weight loss/failure to maintain condition

  • Episodes of colic (remember that colic is a general term used to describe abdominal pain)

  • Picky appetite

However, some horses may not display any clinical signs and yet potentially have severe gastric ulceration.

Diagnosing EGUS

Visualisation of the stomach lining is the only definitive method for diagnosing gastric ulcers.

Gastroscopy involves passing a 3metre flexible endoscope down the oesophagus and into the stomach of the horse. This is usually carried out under sedation and is well tolerated by most horses.

The ulcers are graded by severity from 0 to 4, allowing monitoring of efficacy of treatment and ultimately healing.


Treatment for gastric ulcers is based around reducing the production of gastric acid and increasing the pH environment of the stomach allowing the stomach lining to repair.

The first line of treatment is the use of "Gastrogard" - an oral paste containing the active ingredient Omeprazole. However, in more recent times a 4-week course of injectable omeprazole has been used. It is worth discussing the pros and cons of each treatment type with the vet at the time of the gastroscope.

Management and feeding changes may also be suggested.

A follow-up gastroscopy after an initial course of treatment will aid in evaluating your horse's progress.

How to arrange a gastroscope for your horse

We usually hold gastroscope clinics every 4 months depending on demand. Keep an eye on our facebook page for dates. To secure your place on our gastroscope day, please call the office on 01953600837. We do ask for a £100 deposit.

What to do before the appointment

  • Your horse's last feed should be no later than 6pm the night before

  • Stable on inedible bedding

  • Remove hay and feed bucket after last feed

  • Water must be taken away as early as possible on the morning of the procedure

  • No hay net whilst travelling to the clinic

  • Please remember to bring your horse's bridle and passport

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