What are Gastric Ulcers? Equine Gastric Ulcer Syndrome (EGUS) describes the erosion of the horse’s stomach lining, due to prolonged exposure to the acid produced by the stomach. There are a number of different severities for the condition, which saw a 4-part scoring system being developed.
Grade 0 – Stomach lining intact and no reddening – ie no ulceration
Grade 1 – Some lining is intact but there are areas of reddening present
Grade 2 – Stomach has small single or multiple ulcers
Grade 3 – Stomach has large single or multiple ulcers
Grade 4 – Stomach has extensive ulcers, which often merge to show areas of severe and deep ulceration
Grades 2 and above are considered clinically significant.
How to spot a horse with ulcers? They will probably be picky about their food. They may become grumpy in and out of the stable and will probably object to having their girth tightened or their rugs changed. They may grind their teeth. They may become lacklustre and their coats may be dull. They may be reluctant to go forward and may become downright dangerous when ridden and consequently may be retired prematurely. Ulcers can also lead to severe weight loss and increased bouts of colic and loose faeces.
These are just some of the signs that a horse may have ulceration of the stomach. Some horses may look and appear perfectly healthy but can in fact have low grade ulcers.
Ulceration is more widespread than many think. Studies have shown that prevalence can be as high as 37% in leisure horses, 63% in competition horses and 93% in racehorses.
Gastric Ulcers occur when the acidic gastric juice overpowers the protective factors in the stomach lining. Horses have evolved to be continually eating and as a result, their saliva acts as a buffer and protects the stomach. As the horse has been domesticated, a change in their diet with prolonged periods without food means that the acid can’t be neutralised, leading to ulceration.
There are two types of ulceration as the stomach is covered by two different types of epithelium (layers of cells that line hollow organs and glands which help to protect or enclose organs and produce mucus or other secretions.)
Squamous Ulceration – The majority of equine stomach ulcers occur in this area. This dorsal region is covered by squamous epithelium. Ulcers will appear here as a result of continual exposure to acid secretions produced by the gastric juices.
Glandular Ulceration – A slightly less common presence, ulcers will appear here when the protective mucus layer is compromised. This is most commonly due to a side effect of medication, which has resulted in acid erosion of the stomach lining.
A number of key causes have been witnessed.
Diet – In the natural environment, horses graze for approximately 17 hours a day, continually producing saliva which neutralises the acidity in the stomach. Through our domestication, this grazing time is dramatically reduced and their total roughage intake is limited. Feeding concentrated feeds a couple of times a day may also contribute to ulceration as the horse is eating for just a short period of time.
Stress – Horses do not respond well to stress, whether physical or psychological. Their food intake will often be disrupted as a consequence, resulting in periods of increased stomach acidity.
Exercise – Researchers have found that exercise also increases gastric acid production and decreases blood flow which helps remove the acid. Intensive exercise pushes the acid up and splashes it into the sensitive portion of the stomach.
The condition has increased in recognition over recent years due to the advancements in equine science with the usage of video gastroscopy. This is the only correct way to determine whether ulcers are present in the stomach. It enables veterinarians to see what is going on in the stomach and analyse the stomach wall in great detail before scoring the ulceration using the 0-4 scoring system. Looking at clinical signs alone, diagnosis can often be misread due to the condition sharing symptoms with other ailments.
Your vet will diagnose and treat the condition whilst at the same time nutritional management plays a key role in maintaining health and therefore maximum performance and productivity of horses. Their digestive system works best with a small but steady flow of food. The saliva produced by continually eating acts as a buffer and protects the stomach lining from acid. Bile flows constantly and combines with enzymes to cope with a slow but steady flow of food. Reduced roughage intake and the feeding of concentrated feeds a couple of times a day may also contribute to ulceration as the horse is eating for just a short period of time.
Where possible, you should:
- Provide ad-lib forage or continued access to grass
- Split hay/haylage into a number of haynets and ensure there is always plenty on offer
- Feed smaller and more frequent meals to help buffer the acid in the stomach
- Try to cut out a high carbohydrate diet
- Reduce stress factors such as confinement to the stable. Try and keep the horse as happy as you can!
Although ulcers are highly prevalent in horses, with correct management they can go on to have very healthy, happy and prosperous careers. If you’re concerned about your horse or need additional information, please get in touch with your vet to discuss the matter further.
Thanks to Tara Punter (BSc (Honours) in Equine & Agricultural Business) for supplying me with the facts about gastric ulcers.