Equine Gastric Ulcer Syndrome (EGUS) can present itself in many ways, leaving horses uncomfortable, irritable and in some cases unmanageable. Many horse owners are left frustrated as, without gastroscopic investigation (scoping) which can cause the horse additional stress, the condition can go undiagnosed for considerable periods of time.

In this article we are joined by Saracen Horse Feeds nutritional experts to talk more about the different types of disease, risk factors, clinical signs and nutritional management.

Horses evolved to ingest a high fibre, low starch ration on an almost continual basis. Foraging behaviour is important to the maintenance of a healthy digestive tract, as not only does the flow of forage through the digestive system ensure optimal digestive health but the chewing process produces large amounts of saliva, which helps to buffer the acid that is produced in the stomach.

The way in which we keep and manage horses often means that they are unable to exhibit this normal foraging behaviour and are exposed to high-stress levels such as during training or early weaning, as well as being fed rations that may have high cereal and starch levels with less than optimal forage and fibre allowance catered for. These feeding and management practices have been associated with a high prevalence of EGUS.

EGUS is a general term that is used to describe ulcers in the stomach, however as our understanding of EGUS has evolved the syndrome can now be split into two separate diseases.

Equine Squamous Gastric Disease (ESGD)

1. Affects the white squamous (non-glandular) region of the stomach
2. Result of prolonged exposure, or ‘splash’, from stomach acid, onto the poorly protected upper area of the stomach

Equine Glandular Gastric Disease (EGGD)

1. Affects the pink (glandular) region of the stomach and proximal duodenum

2. Result of impaired mucosal defence in the lower area of the stomach

What horses does EGUS affect?

It was thought to more commonly affect Thoroughbred racehorses, but with the advancement of research and increased ability to be able to study other classes of horses, EGUS has significant prevalence in other classifications of performance horses e.g. show horses, eventers, dressage and endurance horses, as well as being seen in up to 60% of leisure horses. It has also been seen that all ages and breeds of horses and ponies are susceptible to EGUS.

Risk factors associated with EGUS

• Forage being fed at a rate of less than 1.5% of the horse’s bodyweight
• Horses being without forage for longer than 6 hours, especially duringthe hours of 7am – 11pm
• Daily starch intake exceeding 2g per 100kg bodyweight
• Starch per meal intake exceeding 1g per 100kg bodyweight
• Stomach empty of forage during exercise
• Water deprivation
• Administration of NSAIDS
• Reflux of bile acids

Did you know?

When fed hay and pasture, horses produced 400 – 480 grams of saliva per 100 grams of dry matter consumed, whereas when a concentrate feed was fed, horses produced half as much saliva, therefore significantly reducing the buffering capacity.

Clinical Signs

The clinical signs of EGUS can vary from horse to horse and can also be a reflection on that individual horse’s temperament but typical signs include:

• Poor appetite or change in eating behaviour
• Weight loss or failure to thrive
• Irritability and general changes in temperament
• Reduced performance
• Abdominal discomfort to girthing or grooming
• Recurrent mild colic

Nutritional management to reduce the risk of EGUS