Equine Gastric Ulcer Syndrome
Learn what the condition is, how it may be detected early, how it is treated or managed, and which breeds or species are linked to it.
Condition snapshot
A concise guide to the condition’s pattern, detection, management and urgency.
This snapshot is a general guide, not a diagnosis or treatment plan. New, severe or worsening signs require veterinary assessment.
About the condition
Equine gastric ulcer syndrome describes erosions and ulcers affecting the horse’s stomach and nearby upper digestive tract. It includes equine squamous gastric disease, involving the comparatively unprotected upper portion of the stomach, and equine glandular gastric disease, involving acid-producing mucosa with different protective mechanisms. These forms have overlapping signs but do not always share the same causes or response to treatment.
The equine stomach secretes acid continuously. Regular forage and saliva help buffer that acid, whereas long periods without feed increase exposure of the squamous lining. Exercise raises abdominal pressure and can push acidic contents upward, contributing to squamous injury. Intense training, travel, stall confinement, intermittent feeding and high-starch rations increase risk. Glandular disease is less completely understood and is associated with impaired mucosal defence, stress and some medication exposures rather than simple acid splash alone.
Adult horses may show poor appetite, slow eating, mild recurrent colic, weight loss, attitude change, girth sensitivity or reduced performance. These signs are nonspecific, and some horses with substantial lesions show little outward illness. In foals, severe disease may cause poor nursing, teeth grinding, drooling, diarrhoea or lying on the back; perforation can occur in serious cases.
Ulcer severity cannot be judged reliably from behaviour or athletic performance. Other causes of pain, weight loss and poor performance must remain under consideration. Persistent disease can contribute to ongoing discomfort and, less commonly, gastric outflow obstruction or perforation. The presence of an ulcer also does not prove that it explains every clinical sign, particularly in a horse with substantial lameness, dental disease or another source of abdominal pain. Understanding which region is affected matters because treatment duration, additional medication and expected healing may differ between squamous and glandular disease.
Screening & Early Detection
Routine observation should focus on changes in appetite, time taken to eat, body condition, behaviour during grooming or girthing, recurrent mild colic and unexplained performance loss. A useful history covers forage availability, concentrate size, fasting periods, training intensity, transport, stall confinement, social stress and recent anti-inflammatory medication. None of these signs or risk factors confirms ulcers.
Gastroscopy of an appropriately fasted horse is the definitive diagnostic method. A sufficiently long endoscope allows the veterinarian to inspect the squamous mucosa, glandular region, pylorus and accessible proximal intestine. Lesions can be described and graded, although the numerical grade alone does not capture every clinically important feature. Blood tests do not diagnose gastric ulceration, and improvement during empirical acid-suppressive treatment is only presumptive evidence.
Repeat gastroscopy is useful when signs persist, glandular lesions are severe, the treatment course is being extended or objective confirmation of healing is important. Foals showing poor nursing, marked pain, reflux or systemic illness require prompt investigation because serious ulcer complications can progress rapidly. Screening should also consider other causes of the presenting signs instead of attributing every behavioural or performance problem to the stomach.
Treatment & Management
Treatment combines medication with correction of relevant management pressures. Omeprazole is the principal acid-suppressive medication for equine squamous gastric disease, given at a veterinary-directed dose and duration. Glandular disease may require a longer course and additional mucosal-protective treatment such as sucralfate or another diagnosis-specific plan. Product formulation, administration relative to feeding and adherence influence effectiveness, so treatment should not be improvised from human ulcer medication.
Management aims to reduce repeated acid exposure and support normal feeding behaviour. Horses should receive frequent forage where medically appropriate, avoid unnecessary fasting and have concentrate divided into smaller meals. Lower-starch alternatives and some alfalfa may be useful within a balanced ration. Training, travel and turnout should be adjusted realistically rather than assuming medication will overcome unchanged risk factors. Anti-inflammatory drugs should be used only as directed, particularly when excessive exposure is suspected.
Clinical improvement does not guarantee complete healing. Persistent signs, glandular disease or a rapid return to work may justify repeat gastroscopy before medication is stopped. Recurrence is common when the original feeding and training pattern continues, and some horses need a preventive plan during periods of unavoidable risk. Foals with severe ulceration, reflux, dehydration or suspected perforation require intensive supportive care. Prognosis is generally favourable when the lesion type is identified and both medical and management factors are addressed.
Breeds or species affected
Akhal-Teke
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Anglo-Arabian
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Arabian
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Barb
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Caspian
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Kathiawari
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Marwari
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Shagya Arabian
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Thoroughbred
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American Quarter Horse
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American Paint Horse
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Appaloosa
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Australian Stock Horse
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Brumby
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Waler
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Morgan
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Standardbred
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American Saddlebred
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Tennessee Walking Horse
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Missouri Fox Trotter
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Rocky Mountain Horse
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Peruvian Paso
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Criollo
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Mustang
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Canadian Horse
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Andalusian
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Lusitano
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Lipizzaner
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Friesian
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Dutch Warmblood
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Hanoverian
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Holsteiner
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Oldenburg
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Westphalian
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Trakehner
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Selle Français
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Belgian Warmblood
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Danish Warmblood
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Swedish Warmblood
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Swiss Warmblood
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Australian Warmblood
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Irish Sport Horse
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Cleveland Bay
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Württemberger
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Zangersheide
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Knabstrupper
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Orlov Trotter
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Camargue
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Icelandic Horse
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Pony of the Americas
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Quarter Pony
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Miniature Horse
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Clydesdale
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Shire
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Percheron
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Belgian Draft
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Suffolk Punch
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American Cream Draft
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Ardennes
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Breton
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Boulonnais
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Comtois
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Dutch Draft
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North Swedish Horse
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Norwegian Fjord
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Haflinger
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Gypsy Cob
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Irish Draught
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Welsh Pony and Cob
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Connemara Pony
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New Forest Pony
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Dartmoor Pony
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Exmoor Pony
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Shetland Pony
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Highland Pony
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Fell Pony
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Dales Pony
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Australian Pony
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Finnhorse
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Black Forest Horse
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