Equine Gastric Ulcer Syndrome (EGUS) isn’t just a performance horse problem – it can affect any horse or pony, from top athletes to your favourite hacking buddy. Understanding what causes gastric ulcers in horses, how to spot the signs, and natural feeding strategies like fibre mash feeds is essential for prevention and long term gut-health.
EGUS refers to ulceration within the horse’s stomach and can impact comfort, behaviour, performance, and overall wellbeing. While many owners are more clued up today, the why, what, and how behind ulcers still needs clear, practical explanation—especially around management, feeding, and exercise.
Key takeaways:
- Ulcers can occur in any horse or pony, not only racehorses or high‑level performance horses.
- Management factors such as stress, stabling, travel, and high‑starch diets increase risk.
- Prevention focuses on fibre-first feeding, continuous access to forage, and reducing fasting periods.
Understanding the Horse’s Stomach: Acid Zones and Risk Areas
To understand why ulcers happen, you need an understanding of the horse’s stomach. The horse’s stomach has two distinct regions, each with different protection levels against acid:
- The Acid Factory (Lower Glandular Region): Continuously produces strong acid to break down food. It has a protective mucus layer – think of it like a non-stick coating.
- The Danger Zone (Upper Squamous Region): This top section acts like a reservoir, but lacks a protective mucus layer. When acid splashes up here – particularly during exercise or when the stomach is empty – ulcers may form.
Fibre First: Why High-Fibre Diets Protect Against Ulcers
Horses are designed to graze almost continuously. As hindgut fermenters that thrive on fibre and consistent intake.
- The buffer effect: Because the stomach is always making acid, a steady supply of forage creates a fibre mat that literally soaks up the acid and acts as a acid buffer.
- The saliva shield: Chewing fibre stimulates saliva production. Saliva, which is naturally alkaline, helps neutralise stomach acid as the horse swallows.
Modern Management vs Natural Feeding
Our management of performance horses often creates the perfect storm for ulcers:
- Stress and routine changes: Travel, competition, and stabling can spike stress hormones and reduce blood flow to the stomach lining, making it more vulnerable to acid.
- High starch, low fibre diets: Concentrates may be needed for some horses, but excess starch alongside insufficient forage increases EGUS risk.
- Fasting periods: Long gaps without forage mean acid accumulates without the protective saliva and fibre mat.
It’s a myth that ulcers only plague racehorses they can affect any horse or pony.
More recent research shows*:
- Racehorses: Up to 93% are affected.
- Performance/Sport Horses: Around 63% have them.
- Leisure Horses/Ponies: Up to 60% have been reported to have ulcers.
- Foals: Even youngsters are susceptible, with rates between 50–84%!
The Exercise Connection: How Workload Impacts Ulcer Risk
During intense movement stomach contents are sloshed upward, bathing the vulnerable squamous area in acid for longer. Horses worked most days of the week—especially at speed or collection—may show higher ulcer risk. One study even noted that horses exercised for more than five days a week had a 10% higher ulcer rate.
Simple fix: Give your horse hay or a fibre feed like Fibre-Beet before grooming or tacking up. This helps form a protective fibre mat that helps reduce acid splash in the stomach during exercise. Fibre-Beet is a “super-fibre” conditioning feed that alongside beet pulp includes alfalfa for added quality protein and is formulated to keep the gut healthy.
Spotting the signs
There’s no single, simple symptom, but keep an eye out for:
- Girthiness or sensitivity around the belly
- Weight loss or poor coat
- Crankiness or unusual behaviour
- Reduced performance or reluctance to work
- Recurring mild colic
Diagnosis: If you suspect a problem, always call and consult with your vet. The only way to know for sure is a gastroscopy (a camera scope into the stomach), which requires fasting and sedation.
Fibre First: Simple management tips
For long-term protection, remember:
- Fibre: Your horse’s diet should be mostly high-fibre, low-starch forage. Only add concentrates when and if you need extra energy for work.
- Turnout time: Maximise grazing time. This mimics the wild horse’s continuous eating pattern.
- Ad-lib forage: If stabled, always provide hay so they can constantly graze and buffer acid.
- Before work and potentially stressful happenings: Feed fibre (hay or a small fibre mash) before stressful events like a vet visit or travelling to a competition. This acts as a protective barrier against acid splashing.
Fibre-Beet from British Horse Feeds Fibre-Beet has been awarded the Gastric Ulcer Feed Assurance Mark by the British Equestrian Trade Association, confirming it’s a suitable choice for horses prone to EGUS as part of a balanced diet.
To find more information about Fibre-Beet mash go.
