📋 At a Glance
⚠️ Signs That May Indicate Gastric Ulcers — Discuss with Your Vet
- Recurring mild or moderate colic, particularly within an hour of eating or during periods without feed access
- Unexplained decrease in performance, energy, or willingness to work
- Attitude changes — increased irritability, resentment of girthing, sensitivity when touched on flanks or belly
- Teeth grinding (bruxism), especially in foals
- Weight loss or difficulty maintaining body condition despite adequate feed
- Rough, dull hair coat without another explanation
- Foals: frequent lying on their backs, excessive salivation, nursing-then-releasing, diarrhea
- A horse that was previously willing and enthusiastic that has become dull, resistant, or difficult
Understanding EGUS — Two Distinct Disease Processes
The horse's stomach is divided into two regions with fundamentally different tissue types, different acid exposure patterns, and different ulcer profiles. Effective treatment depends on knowing which region is affected — which is why gastroscopy is indispensable.
The squamous region (upper, non-glandular portion — approximately one third of the stomach) is lined with stratified squamous epithelium similar to esophageal tissue. It has no protective mucus layer and no prostaglandin-mediated defenses. When acid splashes onto this tissue — during exercise, long periods without feed, or high-starch feeding — it causes erosions and ulcers that are primarily dietary and management driven.
The glandular region (lower, acid-producing portion) has extensive natural protective mechanisms including mucus, bicarbonate secretion, and prostaglandins. When these defenses fail — from stress, NSAID use, Helicobacter-like organisms, or unknown factors — glandular ulceration develops. EGGUS is often more painful, may produce different clinical signs, and is frequently more resistant to standard omeprazole treatment alone.
EGUS Prevalence — Why It Matters in Performance Horses
The performance horse lifestyle creates multiple compounding risk factors for gastric ulceration. Horses in intensive training commonly receive high-grain diets for energy demands, experience frequent travel and competition stress, may have irregular feeding schedules around events, and are often prescribed NSAIDs for soreness management. Each of these is an independently documented risk factor.
The implication is that most actively competing reining horses, cutting horses, barrel racing horses, and roping horses are operating under significant ulcer risk — and many are competing with active ulceration that is limiting their performance without being recognized or treated. Proactive gastroscopic screening before each competition season is increasingly common in well-managed performance programs.
Signs by Category — Recognizing EGUS in Your Horse
Gastric ulcer signs are notably non-specific — none of them alone is diagnostic, and horses with serious ulceration may show only subtle changes while horses with mild ulcers may appear dramatically uncomfortable. This is why the pattern of signs across multiple categories is more meaningful than any single sign.
| Category | Signs That May Indicate EGUS | Notes |
|---|---|---|
| Performance | Declining times or scores; reluctance to collect; loss of impulsion; early rate; not completing the pattern | Often the most objectively measurable change in competition horses |
| Behavioral | Increased irritability; resentment of girthing; sensitive on flanks/belly; pinning ears under saddle; resistance to leg aids | Often misidentified as "attitude problems" or training resistance |
| Digestive | Intermittent colic, particularly 1 hour post-feeding; recurrent mild colic; decreased appetite; slow eating | Colic timing relative to feeding is a useful clinical clue |
| Physical appearance | Weight loss despite adequate feed; poor body condition; rough, dull coat; poor topline | More common with chronic significant ulceration |
| Foal-specific | Lying on back; salivating excessively; grinding teeth; poor nursing; diarrhea; pot-bellied appearance | Foals may have higher prevalence and more dramatic signs |
The Diagnostic Process — Why Gastroscopy Is Required
Gastroscopy — passage of a 3-meter flexible endoscope through the horse's nostril, down the esophagus, and into the stomach — is the only way to definitively diagnose EGUS, determine which region is affected, and grade severity. No blood test, urine test, or clinical exam can replace it.
The procedure requires a 12–18 hour fast (to empty the stomach) and is performed under standing sedation. The veterinarian can directly visualize the squamous and glandular mucosa, grade ulcer severity on a 0–4 scale, and — critically — determine whether the squamous region, glandular region, or both are involved. This information determines the treatment protocol.
Repeat gastroscopy at the end of treatment — typically 28 days for squamous ulcers — confirms healing before discontinuing medication. Many horses feel better before ulcers are fully healed; stopping treatment early based on clinical improvement alone results in high recurrence rates.
Treatment — What Your Veterinarian May Prescribe
Treatment is determined entirely by your veterinarian based on gastroscopic findings. The following provides educational context on the tools your vet may use — it is not a treatment guide.
Squamous Ulcers (ESGUS)
Omeprazole (Gastrogard, Ulcergard) is the FDA-approved primary treatment. It suppresses acid production, allowing the squamous mucosa to heal. Full-dose treatment for 28 days is typically followed by a recheck gastroscopy. Compounded omeprazole products vary widely in bioavailability — discuss product selection with your veterinarian.
Glandular Ulcers (EGGUS)
Glandular ulcers respond less predictably to omeprazole alone. Your veterinarian may add sucralfate (which coats and protects the glandular mucosa), misoprostol (a prostaglandin analog that supports mucosal defense), or extended treatment duration. Some cases require combination therapy over 60+ days.
Prevention — Management Strategies That Reduce EGUS Risk
The management changes below have consistent support in equine gastroenterology research. Discuss which are most practical and impactful for your horse's specific situation with your veterinarian.
📋 Evidence-Based EGUS Prevention — Discuss with Your Vet
- Ad-lib hay or forage access: continuous forage buffers stomach acid and most closely mimics natural grazing. Even rough hay available at all times is better for ulcer prevention than hay twice daily
- Feed small hay portion before exercise: providing 1–2 kg of hay 20–30 minutes before work is thought to reduce acid splash to the squamous region during exercise
- Reduce high-starch grain quantity: starch fermentation in the stomach produces volatile fatty acids that damage the squamous mucosa; lower-starch, higher-fat energy sources reduce ulcer risk
- Maximize turnout and social contact: stall confinement and social isolation are independently associated with glandular ulcer development in horses
- Manage travel and competition feeding: maintaining consistent hay access during transport and at shows reduces the feeding disruption that drives ulcer recurrence
- NSAID use monitoring: phenylbutazone and flunixin inhibit prostaglandin production, reducing glandular mucosal defenses; discuss lowest effective dose and duration with your vet
- Prophylactic omeprazole during high-risk periods: some programs use half-dose omeprazole during transport and competition periods — discuss with your vet
Questions to Ask Your Veterinarian
- My horse has these signs — do you recommend gastroscopy, or should we try empirical treatment first?
- Which region of the stomach is affected, and how does that change the treatment approach?
- What dose and duration of omeprazole do you recommend, and which product do you prefer?
- Should we add sucralfate or misoprostol to the protocol?
- When should we recheck with gastroscopy to confirm healing?
- What feeding and management changes will have the greatest impact on preventing recurrence?
- Given my horse's competition schedule, when is the highest-risk period for recurrence, and how should we manage that?
