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Equine Gastric Ulcer Syndrome (EGUS)


Equine gastric ulcer syndrome is one of the most common diseases in horses affecting around 70% of competition horses. Despite this, it is often under diagnosed as the signs can be vague and non specific and accurate diagnosis requires visualisation of the stomach using an equine gastroscope.


In their natural environment horses will spend upto 16 hours a day eating. Saliva is continually produced in response to regular eating and this helps to buffer the acid produced in the stomach. The stomach is composed of a glandular area at the bottom which has various mechanisms to protect itself from the acid. The top portion of the stomach is non glandular and has no defensive mecahnisms against stomach acid, however, in the natural environment it rarely comes into contact with the acidic stomach contents. 


The general management of domestic horses means they have reduced forage intake, the reduction in time spent eating means less saliva is produced and there is less neutralisation of the stomach acid.  Additionally, fast paced exercise and jumping, causes stomach acid to splash onto the non glandular portion of the stomach.  These factors can cause pain and ulceration.


As mentioned, clinical signs of gastric ulcers can be non specific. They include; poor performance, loss of condition, weight loss, teeth grinding and crib biting, back pain and pain on tightening the girth, colic, diarrhoea  and problematic behaviours when riding such as refusal to go forwards, bucking and refusal to jump.


Gastric ulcers are diagnosed by the use of a gastroscope. This is performed under sedation at our clinic using in our purpose made stocks using a 3M gastric endoscope. Patients should be starved for 12 hours prior to gastroscopy and water should be removed 4 hours beforehand.  The gastroscope is passed through your horse's nose and down his oesophagus into his stomach.  The oesophagus, stomach and proximal duodenum can all be visualised and thoroughly inspected to determine the presence of ulceration which is graded on a scale of 1 to 4.


We prefer to carry out gastroscopy at the clinic but we can do it on your yard; horse must be starved prior to the procedure in order to ensure the stomach is empty.

If you decide to bring your horse to the clinic on the day of the procedure you must: 

- Give him/her their last feed at 6pm the evening before.

- Stable on a non-edible bedding

- Leave water available until the morning of the procedure

- No hay/feed to be given whilst travelling.


Omeprazole, a proton pump inhibitor, helps to reduce the amount of acid produced by the glandular stomach. Other drugs such as cimetidine and ranitidine (known as H2 receptor antagonists) can also help to reduce the volume of acid produced.  Sucralfate is a gastric protectant and helps to line the stomach to prevent damage occuring.  Management is a large factor in preventing the occurrence of gastric ulcers. Trying to reduce the amount of time your horse goes without eating will help to minimise acid build up.  Increasing turnout and feeding ad lib hay in the stable whilst reducing the amount of hard feed will asssist with this.  Feeding a small amount of hay or feed before riding may help to absorb the stomach acid and reduce the amount of acid splashing up the walls of the stomach while riding.


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