Gastric Ulcers in Horses: What Every Horse Owner Should Know

Gastric ulcers are one of the most common, and often under-recognised, conditions affecting horses in Australia. From elite racehorses to pleasure horses, ulcers can significantly impact performance, behaviour, and overall wellbeing. The good news is that with accurate diagnosis and targeted treatment, most affected horses recover well.

 

What are Gastric Ulcers?

Equine Gastric Ulcer Syndrome (EGUS) refers to ulceration of the stomach lining. The horse’s stomach is divided into two regions: the squamous (upper) portion and the glandular (lower) portion. Ulcers can develop in either or both areas, and the underlying causes differ slightly between them.

Horses naturally produce stomach acid continuously, since they are adapted to almost continuous grazing. In modern management systems, where horses are often stabled, fed intermittently, and exercised intensively, this constant acid exposure can damage the stomach lining.

 

Which horses are at risk?

While any horse can develop ulcers, certain groups are particularly susceptible:

  • Performance horses, especially racehorses

  • Horses in regular training or competition

  • Horses with limited access to forage

  • Horses experiencing stress (transport, confinement, social disruption)

  • Horses receiving high-concentrate, low-fibre diets

Studies suggest that up to 90% of racehorses in training may have some degree of gastric ulceration.

 

Signs to watch for

Clinical signs can be subtle and inconsistent and are often mistaken for behavioural or training issues. Common indicators include:

  • Poor performance or reluctance to work

  • Changes in temperament, irritability, or girthiness

  • Reduced appetite or selective feeding

  • Weight loss or poor body condition

  • Mild, recurrent colic

  • Dull coat or general lack of condition

Not all horses will show obvious signs, which is why ulcers are frequently missed without proper investigation.

 

How are ulcers diagnosed?

The only definitive way to diagnose gastric ulcers is via gastroscopy. This procedure involves passing a specialised endoscope into the stomach, allowing direct visualisation of the lining.

In our practice, we offer gastroscopy as a safe and reliable diagnostic tool. The procedure is performed under light sedation, and horses are fasted beforehand to allow clear visualisation. Gastroscopy not only confirms the presence of ulcers but also allows us to determine their severity and location, critical information for effective treatment.

 

Treatment and management

Treatment depends on the type and severity of ulcers but commonly includes:

  • Acid suppression therapy (such as omeprazole pastes)

  • Dietary modification to increase fibre intake

  • Reducing stress and altering management practices

  • Adjusting training schedules where needed

For glandular ulcers, additional medications or longer treatment courses may be required.

 

Preventing recurrence

Management plays a key role in both treatment and prevention. Practical strategies include:

  • Providing constant access to forage (e.g., hay or pasture)

  • Minimising long periods without feed

  • Reducing high-starch concentrates where possible

  • Incorporating turnout and social interaction

  • Using ulcer-preventative strategies during high-risk periods (e.g., travel, competition)

 

When to seek veterinary advice

If your horse is showing changes in behaviour, performance, or appetite, it is worth considering gastric ulcers as a potential cause. Early diagnosis can prevent progression and improve outcomes.

If you would like to discuss whether gastroscopy is appropriate for your horse, or to book a procedure, please contact us at admin@beaequine.com.au.

 

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