EGUS (Equine Gastric Ulcer Syndrome) is a condition we diagnose more and more and which can have a significant impact on both a horses behaviour and its performance.

Historically, people thought that ulcers only occur in competition- and racehorses, in horses with no turn out and that they are usually thin and have a dull coat. Due to the increasing awareness and improved diagnostic techniques more and more horses are actually examined and we have learned that gastric ulcers effect leisure horses as much as  competition horses, even horses with 24/7 turn out and most of them are actually in good condition and do have shiny coats.

Often the displayed symptoms can be quite drastic – weight loss, recurrent colic episodes, extreme behaviour like biting, bucking or rearing when girthed up, being ridden or even just without obvious reason. However we frequently find stomach ulcers in horses that only show very subtle signs – owners report “he doesn’t quite perform as well as he used to”, “she looks unhappy when I touch her belly”, “he occasionally lies down and looks at his belly” or “he is just not himself”.

The symptoms can be both subtle and rather unspecific so that EGUS is often only one of several possible causes. It is also important to note that ulcers can occur ALONGSIDE other conditions like kissing spines or hormonal issues.

The only way to reliably diagnose EGUS is via Gastroscopy. For this procedure the horse needs to be withheld food for about 16 hours and it gets sedated. A long flexible tube with a camera on the end is introduced through the nostril and once swallowed it is advanced through the food pipe into the stomach. Via the gastroscopy will be determined not only if ulcers are present, but also where they are (squamous and/or glandular) and how severe they are (Grade 1 -4). This information is critical in order to decide which treatment the horse should receive (Omeprazole-Gastrogard, Sucralfate, Antibiotics) and also to determine the duration of the initial course of treatment (usually 4-8 weeks, however some horses require a longer course). Before treatment is stopped a follow up gastroscopy should be performed as discontinuation before the ulcers have fully healed will most likely lead to rapid reoccurrence.

So what are the causes? When the protective lining of the stomach is exposed to gastric acid for a prolonged period of time it gets damaged, inflammation develops which ultimately results in ulceration. Horses are so called “trickle feeders” – unlike humans they produce gastric acid 24/7! In the wild horses spend 16-18 hours a day eating forage (spread out over 24 hours, not 16 hours eating, then 8 hours not eating), which has two main effects – firstly the saliva produced by chewing is swallowed and constantly buffers down the stomach acid and secondly the forage builds a fibre matt in the stomach which prevents acid from splashing onto the stomach walls. Other contributing factors are stress, chronic pain, bacterial involvement and the use of NSAIDs like Bute.

Therefore alongside the treatment an optimisation of the horses’ management is equally important for the recovery and to prevent reoccurrence:

  • Turn out as much as possible
  • 24/7 access to forage
  • Feeding of as much as a bucket of chaff before riding/travelling to achieve that fibre matt
  • Using buffering feed supplements
  • Low sugar/low starch diets, divided into multiple small portions
  • Possibly a maintenance dose of gastrogard when competing/travelling

These recommendations are advisable for all horses in order to prevent EGUS as much as possible. However, once ulcers have developed management changes alone are unlikely to be sufficient and treatment is necessary. Equally treatment alone without long term management will only lead to a short term success!

If those measures are taken the prognosis for this condition is good if no underlying causes are present.


About the author : Natascha Stemler

Natascha Stemler
Natascha regularly performs gastroscopies at the practice to diagnose potential gastric ulceration in horses.

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