Equine Gastric Ulcers Part 2: Prevention

"Okay Nicole, enough science.  I just want to know how to reduce my horse's ulcer risk without spending a fortune on treatment." Fair enough. Let's talk prevention.

If you missed part one, here's the short version: ulcers develop when highly acidic stomach contents either splash onto the sensitive squamous region or overwhelm the protective barriers of the more resilient glandular region. Two different regions, two different failure modes — and prevention means protecting both.

Forage first. Always.

Long-stem forage, primarily hay, should make up the foundation of every horse's diet. For a healthy mature horse, aim for 1.5–2% of body weight per day, that's approximately 15–20 lbs for a 1,000 lb horse.

Why does forage matter so much for ulcer prevention? Chewing. Long-stem forage maximizes chew time, which drives saliva production. Saliva is naturally more basic and acts as a buffer against stomach acid so the more your horse chews, the more protection they have.

Minimizing fasting intervals is equally important. The horse's stomach produces acid continuously whether they are eating or not. Long gaps between meals mean acid accumulating in an empty stomach with nothing to buffer it. Forage access throughout the day is one of the most powerful tools we have.

Manage Exercise carefully, especially on an empty stomach.

During exercise, increased abdominal pressure can force acidic stomach contents upward onto the sensitive squamous region. This is acid splash, which performance horses are particularly vulnerable to.

Two things can help:

A small hay meal before work serves double duty. It buffers stomach acid through saliva production and chewing, and the forage itself sits on top of the acid forming a physical barrier that reduces splashing onto the squamous region.

A stomach buffering supplement can help lower the acidity of the stomach contents, but it doesn't provide that same physical protective barrier that forage does. Both together offer the most comprehensive protection.

The takeaway: don't work your horse on a completely empty stomach. Even a small flake of hay 30–60 minutes before exercise makes a meaningful difference.

Diet composition. What's actually in your horse's concentrate matters.

High starch and high sugar feeds are problematic for ulcer-prone horses for several reasons. Evidence suggests that increased sugars can raise the acidity of stomach acid. High starch meals also move through the gastrointestinal tract faster than fiber-based feeds and when starch reaches the hindgut before its fully digested, fermentation produces volatile fatty acids (VFAs).

It's worth noting that VFAs are actually the primary energy source for horses, produced through normal hindgut fermentation of fiber. The problem arises with excess VFA production from starch spillover.  In an already acidic environment, these excess VFAs may contribute to damage of the protective barrier of the glandular region, which is the region that relies on that barrier to defend itself against continuous acid secretion.

What to prioritize instead:

·       Higher fiber, lower starch concentrates

·       Smaller, more frequent meals rather than large infrequent ones

·       Forage-based calories wherever possible

The goal is to keep the stomach environment as stable as possible, and a fiber-forward diet does that far better than one built around grain and starch.

Stress management. Easier said than done when you're dealing with a 1,000 lb flight animal afraid of a plastic bag.

The relationship between stress and ulcers is not yet fully understood, but the evidence suggests that elevated cortisol levels can alter blood flow to the stomach and impair the protective mechanisms of the glandular region, making it more vulnerable to acid damage even when everything else is managed well.

The good news is that the prescription for stress management looks a lot like what horses were designed to do in the first place. To mimic the lifestyle of wild and feral horses as closely as management allows:

·       Maximize turnout — outside time reduces physiological and psychological stress

·       Allow grazing with the head down — natural posture, natural behavior

·       Provide social contact — horses are herd animals and isolation is genuinely stressful

·       Keep routine consistent — predictability matters more than people realize

·       Allow movement — horses in the wild cover miles daily

You don't have to have a perfect setup. But every step toward a more natural lifestyle is a step toward a healthier stomach.

A quick note on supplements. Keep it simple.

You don't need to spend a fortune on a cabinet full of products. A stomach buffering supplement is a reasonable option if you're looking for additional support, particularly around exercise or periods of increased stress. If you want to go a step further, a well-reviewed pre- or probiotic can support overall gut health and complement your prevention strategy.

But that's really it. More supplements do not mean more protection and an overcomplicated feeding program can create its own problems.

Most importantly: if you suspect your horse already has ulcers, please involve your veterinarian. Gastric ulcers cause real damage to the stomach lining and medical treatment is often necessary for proper healing. Nutrition and supplements support the stomach; they do not replace veterinary care.

Prevention isn't about eliminating stomach acid, that's not possible and nor is it desirable. It's about supporting the systems that manage it. Forage, exercise management, diet composition, stress reduction, and judicious supplement use, these aren't complicated interventions. They're a return to what horses were designed to need.

If you missed part one on the physiology behind ulcer development, start there — it makes everything here make more sense.

And as always, stay curious. 🐴