What Causes Stomach Ulcers in Horses? Understanding Risk Factors and Prevention

Stomach ulcers in horses are more common than many horse owners realize. In fact, a large percentage of performance horses - and even some leisure horses - experience some level of gastric discomfort during their lifetime.

If you’ve been searching “what causes stomach ulcers in horses,” the answer isn’t just one thing. Ulcers typically develop due to a combination of diet, management, and lifestyle factors that affect the horse’s stomach environment.

Why Horses Are Prone to Ulcers

A horse’s stomach continuously produces acid - whether they are eating or not.

In a natural grazing environment, this isn’t an issue because:

• Horses eat small amounts throughout the day

• Forage helps buffer stomach acid

But modern management often looks very different.

When natural eating patterns are disrupted, the stomach becomes more vulnerable to irritation and ulcer formation.

Common Causes of Stomach Ulcers in Horses

1. Long Periods Without Forage

Horses are designed to graze consistently. When they go long periods without hay or pasture, stomach acid can build up and irritate the stomach lining.

2. High Grain, Low Forage Diets

Diets high in concentrates and lower in forage can increase acid production and reduce the natural buffering effect that forage provides.

3. Stress and Routine Changes

Stress is one of the biggest contributing factors.

This can include:

• Travel

• Competitions

• Changes in environment

• New routines or schedules

Even subtle changes can impact digestive health.

4. Intense Training and Workload

Exercise increases pressure within the stomach, which can cause acid to splash onto more sensitive areas of the stomach lining - especially during more intense work.

5. Limited Turnout

Reduced turnout often means:

• Less grazing

• More time without forage

• Increased stress

All of which can contribute to ulcer development.

6. Intermittent Feeding Schedules

Feeding larger meals less frequently, rather than smaller, consistent meals, can leave the stomach empty for longer periods - allowing acid to accumulate.

How These Factors Work Together

Ulcers rarely come from a single cause.

Instead, they develop when multiple risk factors combine, such as:

• A high-grain diet

• Limited forage access

• Regular travel or competition

This is why even well-managed horses can still be at risk.

Supporting Digestive Health

Because many of these factors are part of everyday horse management, the goal isn’t always to eliminate them - but to support the horse through them.

A well-rounded approach includes:

• Consistent access to forage

• Managing feeding schedules

• Minimizing unnecessary stress

• Supporting the digestive system during higher-risk periods

A Proactive Approach

For horses in work, travel, or changing routines, digestive support can play an important role in maintaining comfort and performance.

A product like Uls-Gard Pellets is designed to help:

• Support the stomach lining

• Maintain digestive balance

• Provide daily support in higher-risk situations