Understanding Equine Gastric Ulcer Syndrome (EGUS): A Guide for Horse Owners
Gastric ulcers are a widespread issue in horses, particularly among performance, sport, and even leisure horses. Equine Gastric Ulcer Syndrome (EGUS) occurs when the lining of the horse’s stomach is damaged by excessive acid exposure, leading to pain, poor performance, and behavioural changes.
Studies show that EGUS affects:
- 80–100% of racehorses
- 93% of endurance horses during competition
- 58% of show and sport horses
- 11% of leisure horses
- Up to 57% of foals – with risk rising to 97% after weaning
Given these statistics, it’s crucial for horse owners to understand the signs, causes, and treatments of this common but often overlooked condition.
What Causes Gastric Ulcers in Horses?
Unlike humans, horses produce stomach acid continuously—even when not eating. When their stomachs are empty for extended periods, the unbuffered acid can damage the stomach lining, especially the squamous (upper) region.
Key risk factors include:
- Fasting & Limited Forage: Long gaps between meals allow acid to build up.
- High-Grain Diets: Increase acid production and reduce protective saliva.
- Intense Exercise: Causes acid to splash upward, irritating the stomach lining.
- Stress: Travel, competition, stall rest, and routine changes all contribute.
- NSAID Use: Medications like bute, Danilon, or Fynadine can reduce natural defenses.
- Limited Turnout: Horses kept in stalls are more prone to ulcers than those on pasture.
Recognising the Signs
Symptoms of gastric ulcers can be subtle and are often mistaken for behavioral or training issues. Some horses show no outward signs, even with severe ulcers.
Look out for:
- Decreased appetite, especially for grain or concentrates
- Weight loss or poor body condition despite normal intake
- Behavioural changes such as girthiness, bucking, or resistance to work
- Dull coat
- Mild or recurrent colic especially after eating
- Excessive salivation or teeth grinding, often misattributed to dental problems
Diagnosing EGUS
The most reliable way to diagnose EGUS is through gastroscopy – a procedure where a camera is passed into the stomach to inspect for ulcers directly. Prior to the procedure, horses must be fasted (no food for 12 hours, no water for 4 hours) to ensure clear visibility.
Treating Gastric Ulcers
The goal of treatment is to reduce stomach acid and support healing, often through a combination of medication and lifestyle management.
Treatment options include:
- Omeprazole (Gastrogard/Peptizole): The only UK-licensed treatment; reduces acid production. Typically given once daily for 4 weeks, followed by a tapering dose.
- Sucralfate: Coats and protects the stomach lining, often used alongside omeprazole.
Nutritional adjustments:
- Provide constant access to hay or pasture
- Reduce high-starch and grain feeds
- Offer small, frequent meals
- Use slow feeders if ad lib hay isn’t feasible
- Feed a small amount of alfalfa 30 minutes before work to reduce acid splash
Stress management:
Maximise turnout, reduce travel, and adjust training routines.
Preventative treatment:
- Consider omeprazole during times of high stress or competition.
Most horses begin to feel better within a few days of starting treatment, but full healing can take 3-4 weeks or more, depending on severity. A follow-up gastroscopy is recommended to ensure ulcers have resolved.
How We Can Help
At Shotter & Byers, we offer gastroscopy services both at a facility we work closely with based in Epsom or at your own yard.
Whether you’re concerned about your horse’s behaviour, performance, or just want peace of mind, our team is here to support you every step of the way.
**Get in touch today to schedule a consultation or gastroscopy appointment. **
