Equine Squamous Gastric Disease in Horses: Signs and Management
- Equine squamous gastric disease, or ESGD, is ulceration of the upper squamous portion of the horse's stomach, where tissue is less protected from acid.
- Common signs include poor appetite, mild recurrent colic, attitude changes, weight loss, girthiness, and reduced performance, but some horses have very subtle signs.
- Gastroscopy is the most reliable way for your vet to confirm ESGD and to grade how severe the lesions are.
- Management usually combines medication with changes in forage access, meal frequency, exercise routine, travel stress, and stall time.
- Many horses improve well with treatment, but recurrence is common if the underlying management risks are not addressed.
What Is Equine Squamous Gastric Disease in Horses?
Equine squamous gastric disease, or ESGD, is a form of equine gastric ulcer syndrome that affects the upper, squamous-lined part of the stomach. This area does not have the same natural protection against acid as the lower glandular stomach. When acid repeatedly splashes onto that sensitive tissue, erosions and ulcers can develop.
Horses produce stomach acid continuously, even when they are not eating. That matters because horses are designed to graze for much of the day. Long gaps without forage, high-intensity exercise, stall confinement, travel, and other stressors can all increase acid exposure in the squamous stomach.
ESGD is especially common in performance horses. Merck notes that gastric ulcers are found in about 30% of adult horses overall, but the prevalence can rise to up to 90% in racehorses and is also high in show, event, western performance, and endurance horses. Horses on pasture tend to have lower risk than horses in more intensive management systems.
The good news is that many horses respond well when treatment and management changes are paired together. The challenge is that signs are often vague, so it is easy to miss the problem or confuse it with training, behavior, or other digestive issues.
Symptoms of Equine Squamous Gastric Disease in Horses
- Poor appetite or leaving grain, especially when signs are mild to moderate
- Mild recurrent colic or abdominal discomfort, often after exercise or around feeding changes
- Weight loss or poor body condition in ongoing cases
- Attitude changes, irritability, or seeming less willing to work
- Reduced performance, including reluctance to go forward or train normally
- Girthiness or sensitivity around the belly in some horses
- Dull coat or generally looking 'off' without a clear cause
- Teeth grinding, excessive salivation, or lying down more than usual in severe cases
Many horses with ESGD have subtle, nonspecific signs. A horse may seem cranky, picky with feed, less comfortable under saddle, or mildly colicky off and on. Those signs do not prove ulcers, but they are enough to justify a conversation with your vet.
See your vet promptly if your horse has repeated colic episodes, noticeable weight loss, worsening appetite, or a clear drop in performance. See your vet immediately for severe abdominal pain, repeated rolling, inability to eat, or signs of dehydration, because ulcers are not the only cause of these problems and some emergencies can look similar.
What Causes Equine Squamous Gastric Disease in Horses?
ESGD develops when the acid-sensitive squamous lining is exposed to stomach acid often enough to cause injury. In horses, acid is produced continuously. If the stomach is empty for long periods, there is less forage and saliva available to help buffer that acid.
Common risk factors include intermittent feeding, limited forage, high-grain or high-starch diets, stall confinement, strenuous exercise, travel, training stress, and changes in housing or herd structure. AAEP client guidance also highlights that feeding only twice daily and prolonged time without feed can increase ulcer risk.
Exercise plays a major role in many athletic horses. Increased abdominal pressure during work can push acidic stomach contents upward onto the squamous mucosa. Merck also notes that ulcer severity tends to rise as exercise intensity increases, and ulcers can develop quickly under the right conditions.
NSAIDs such as phenylbutazone can contribute to gastric injury, especially if used at excessive doses or in horses with other risk factors, but they are not the main cause in most adult horses with ESGD. Your vet will also think about other possible contributors, because poor appetite, weight loss, and colic can overlap with dental disease, parasites, hindgut disease, pain, and training-related stress.
How Is Equine Squamous Gastric Disease in Horses Diagnosed?
The most reliable way to diagnose ESGD is gastroscopy, also called gastric endoscopy. Merck states that neither clinical signs nor routine laboratory tests are specific for gastric ulcers, and that endoscopy is the only reliable diagnostic method. During the procedure, your vet passes a long endoscope through the nose and into the stomach to directly examine the lining.
To get a good view, horses are usually fasted before the procedure. In practice, many equine hospitals and clinics recommend about 12 to 16 hours off feed and a shorter period off water, though your vet will give the exact instructions for your horse. Sedation is commonly used so the exam can be performed safely and thoroughly.
Gastroscopy helps your vet confirm whether ulcers are present, identify whether the disease is squamous, glandular, or mixed, and grade severity. That matters because treatment plans and expected response can differ depending on which part of the stomach is affected.
In some situations, your vet may discuss an empirical treatment trial if scoping is not immediately available. That can be practical, but it is less precise. If signs persist, recur, or do not fit the expected pattern, gastroscopy becomes even more valuable because it helps avoid treating the wrong problem.
Treatment Options for Equine Squamous Gastric Disease in Horses
Spectrum of Care means you have options. Here are treatment tiers at different price points.
Budget-Conscious Care
- Veterinary exam and history review
- Management-focused plan without immediate gastroscopy in selected mild, stable cases
- Increased forage access or slower-feed hay strategies
- More frequent feeding and reduced fasting periods
- Reduction in high-starch concentrate where appropriate
- Short veterinary-guided medication trial, often centered on acid suppression
Recommended Standard Treatment
- Gastroscopy to confirm and grade lesions
- Prescription omeprazole treatment, commonly for about 28 days, with dose and duration set by your vet
- Targeted feeding and turnout changes to reduce recurrence risk
- Review of exercise schedule, travel stress, and stall time
- Follow-up exam and treatment adjustment based on response
Advanced / Critical Care
- Gastroscopy plus repeat gastroscopy to document healing
- Broader workup for mixed gastric disease or other causes of ongoing signs
- Adjunct medications such as sucralfate when your vet feels they are appropriate
- Detailed nutrition review and performance-management plan
- Hospital-based care or intensive monitoring for horses with severe signs, repeated colic, or poor response
Cost estimates as of 2026-03. Actual costs vary by location, clinic, and individual case.
Questions to Ask Your Vet About Equine Squamous Gastric Disease in Horses
Bring these questions to your vet appointment to get the most out of your visit.
- Do my horse's signs fit ESGD, or are there other conditions we should rule out first?
- Is gastroscopy the best next step for my horse, and what fasting instructions should I follow before the exam?
- Do you suspect squamous disease, glandular disease, or both?
- What treatment options fit my horse's workload, housing setup, and budget?
- How long should my horse stay on omeprazole, and do you recommend any additional medications?
- What feeding changes would most reduce my horse's ulcer risk at home or at the barn?
- When can my horse return to full work, travel, or showing?
- When should we re-scope, and what signs would mean the plan needs to change sooner?
How to Prevent Equine Squamous Gastric Disease in Horses
Prevention focuses on making the horse's daily routine more compatible with how the equine stomach works. The biggest themes are more forage, fewer long fasting periods, and less unnecessary stress. AAEP advises free-choice access to grass or hay whenever possible, more frequent feeding, and reducing grain that contributes to volatile fatty acid production.
Turnout can help, especially for horses that otherwise spend long hours stalled. Horses on pasture generally have lower ulcer risk than horses in intensive training and confinement systems. If full turnout is not possible, your vet may suggest practical changes such as slow feeders, extra hay meals, social contact, or adjustments to the training schedule.
For horses in heavy work, travel, or show circuits, prevention may also include veterinary-guided medication during known high-risk periods. Merck notes that proton pump inhibitors are effective for both treatment and prevention in horses. That said, preventive medication works best when paired with management changes rather than used as the only strategy.
If your horse has had ulcers before, keep a close eye on appetite, body condition, attitude, and performance. Early changes are often subtle. A prompt check-in with your vet can help you address a flare before it becomes a bigger setback.