Investigation of gastric ulcers

Gastric ulceration of the squamous and glandular mucosa of the stomach has been found in studies to affect up to 93% of horses. Traditionally racehorses and sports horses have been most affected however we are seeing more of the condition in leisure horses.

Common signs of gastric ulceration disease are:

  • Poor ridden performance
  • Resistance to girthing
  • Recurrent episodes of colic
  • Weight loss

The only way to definitively diagnose equine gastric ulceration is to pass an endoscope via the nose into the horse's stomach.  This is called gastroscopy.

Grade 3/4 ulceration of the squamous mucosa of the stomach.

Prior to the procedure the horse should be stabled, and no food should be given for 16 hours before the gastroscopy. The horse can still have water until 1 hour before the gastroscope.   We advise that horses come into the clinic the night before to ensure they are adequately starved. 

The Procedure 

The horse will be sedated and positioned within our stocks. The gastroscope is then passed through one nostril into the throat, once swallowed it will pass down through the oesophagus into the horse’s stomach. The stomach is then gently inflated with air – this stretches out the folds within the lining of the stomach to allow for a detailed examination to take place.  The stomach is then examined following a standard protocol to ensure all regions are checked, with images taken to record our findings. 


Following the gastroscopy, we will relate the findings to you and discuss if treatment is required. Depending on the location and severity of ulceration different treatments will be used. In most cases horses that receive treatment will be re-examined at 4 weeks to evaluate the response to treatment. We will also discuss management and dietary changes that will aid in treating and preventing further ulceration.