Equine Gastric Ulcer Syndrome: Expert Advice and Information

Equine Gastric Ulcer Syndrome

Equine Gastric Ulcer Syndrome: Expert Advice and Information

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

The different areas of the horse's 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

  • Horses should ideally be allowed ad-lib access to forage, meaning the horse has forage at all times. If this is not possible because your horse is a good-doer NEVER feed less than 1.5% of the horse’s body weight as forage and look at ways in which the forage being fed can be made to last longer, such as:
    • Putting hay in a small holed haynet
    • Putting different haynets around the stable/field to encourage browsing behaviour
    • Giving the hay allowance spread throughout the day rather than one amount in the morning and one amount in the evening
  • If not feeding ad-lib aim to feed 80% of the horse’s daily forage allowance between the hours of 7am and 11pm
  • Restrict cereal and starch intake
    • Less than 2 g/Kg BW starch per day and less than 1g / Kg BW per meal.
    • Look for feeds containing the BETA EGUS Approval Mark as these feeds will ensure you are stayingbelow this starch threshold if feed at the recommended intake
  • If extra energy/calories are needed consider adding a high oil supplement to the diet to increase calories whilst minimising starch intake
  • Consider feeding an alfalfa chaff
    • Alfalfa is high in calcium which has a buffering effect on stomach
    • 100-200 grams per 100 Kg bodyweight is suitable (i.e. 0.5 – 1kg for a 500kg horse)
  • Supplement the diet with corn oil (50 – 100ml, 1 – 2 times per day)
    • Helps to support the mucosal layer in the glandular region of the stomach.
  • Feed a Stubbs scoop of chaff within 30 mins of exercise
    • Helps to ‘trap’ acid and limit ESGD caused by acid splashing to upper areas of the stomach
    • Improves gastric blood supply
  • Provide constant access to water.
  • Look at ways of helping to reduce stress levels.
  • Consider using an antacid and/or buffering gastric supplement
  • Helps to support and maintain a normal stomach environment

For information on what products Saracen Horse Feeds have available for horses’ suffering from Equine Gastric Ulcer Syndrome visit our feed recommendation page.

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