Horse Gastric Ulcers: Equine Ulcer Syndrome and Welfare

Equine gastric ulcer syndrome (EGUS) affects the majority of performance horses and many leisure horses. Understanding causes and treatment improves welfare for affected horses.

Key Facts

EGUS affects approximately 90% of racehorses and 60% of performance horses in active training
Squamous gastric ulcers in the upper stomach are caused by acid exposure from reduced buffering by saliva
Glandular ulcers in the lower stomach involve different mechanisms including compromised mucosal defense
Omeprazole is FDA-approved for treatment and effective for squamous but less so for glandular ulcers
Horses evolved to graze continuously - prolonged feed restriction removes the buffering effect of hay and saliva
Stalling, high-grain diets, and intensive training are primary risk factors
Sucralfate and misoprostol are used for glandular disease with varying evidence quality

Welfare Considerations

Gastric ulcers cause chronic pain that significantly affects horses' quality of life and behavior. Horses with active ulcers show poor performance, reduced appetite, behavioral changes including irritability when girthing, and in severe cases clinical signs of colic. The pain is present throughout the day - not just at exercise - affecting the horse's basic comfort continuously. The high prevalence of EGUS in performance horses reflects how far management practices have diverged from the continuous grazing lifestyle horses evolved for. Addressing management alongside medical treatment provides more durable welfare improvement than medication alone.

What You Can Do

Maximize forage access and minimize time without hay - empty stomach time dramatically increases ulcer risk
Feed small amounts of chaff or hay before exercise to provide acid buffering during training
Reduce grain intake proportionally as high-starch diets increase acid production
Discuss omeprazole treatment with your veterinarian if ulcers are confirmed by gastroscopy
Implement dietary and management changes alongside medical treatment for sustainable welfare improvement
Consider gastroscopy to confirm diagnosis before committing to prolonged treatment
Monitor for behavioral signs of ulcer pain including sensitivity to grooming and reluctance to be girthed