Ulcer Prevention

Equine gastric ulcers represent a widespread health problem affecting performance horses, pleasure horses, and horses in various competitive disciplines, making prevention one of the most practical and cost-effective approaches to supporting equine health. Unlike diseases with single clear causes, ulcer development results from complex interactions between stomach acid production, the stomach's protective mechanisms, diet, exercise, stress, and individual predisposition. Understanding these multiple factors allows horse owners to implement comprehensive prevention strategies that reduce ulcer development risk substantially.

The prevalence of gastric ulcers in horses is remarkably high, with studies showing that the majority of performance horses have some degree of gastric ulceration even though many show no clinical signs. Foals, young horses, competition and racing horses, and horses maintained in stressful environments show particularly high ulcer incidence. The widespread nature of the problem makes prevention all the more important, as even mild ulceration can affect performance, attitude, and digestive efficiency.

Colonic ulcers, less well understood than gastric ulcers, occur when the colon's protective lining becomes damaged through various mechanisms. Right dorsal colitis, an inflammatory condition affecting the colon, is sometimes associated with NSAID use and develops in horses subjected to intensive training. Prevention of colonic ulcers involves similar strategies as gastric ulcer prevention, including stress reduction, appropriate NSAID use, and dietary management.

Prevention of ulcers through management and dietary modification represents a far more practical approach than treating established ulcers, particularly for horses returning to competition or performance after treatment. Medication to prevent ulcer development in high-risk horses extends the duration between treatment periods and reduces recurrence rates. Understanding prevention strategies allows owners to intervene before ulcers develop or recur.

This guide provides comprehensive information about the factors contributing to ulcer development, practical prevention strategies addressing multiple causative mechanisms, dietary approaches that support gastric health, stress management techniques, and guidance about preventive medication use in high-risk situations. You will learn to recognize which horses are at highest risk for ulcer development, understand how to modify management to reduce risk, and appreciate when preventive medication is warranted. Armed with knowledge about ulcer prevention, you can support your horse's digestive health and potentially avoid the performance and health problems associated with ulceration.

Gastric acid production represents the fundamental mechanism underlying all gastric ulcers, with stomach acid continuously secreted even when the stomach is empty. Horses that graze frequently in natural settings consume forage throughout the day, keeping their stomach relatively full and buffered by feed material. However, horses maintained in stall-based systems with feeding schedules of two to three large meals daily experience periods of several hours when the stomach is empty but acid is still being secreted. This empty stomach acid environment creates the acidic conditions that damage the stomach's protective lining.

The amount of time the stomach remains empty directly influences ulcer risk, with horses kept in minimal forage environments or subjected to extended periods without feed access showing dramatically higher ulcer incidence. Competition and training schedules that involve transportation, time away from forage, or restricted feeding increase empty stomach time. Fasting before exercise or competition, sometimes recommended by riders but not physiologically necessary, dramatically increases ulcer risk by extending the period of empty stomach acid exposure.

Diet composition significantly influences ulcer development risk, with high-grain, low-forage diets associated with increased incidence. Grain is processed more rapidly through the stomach than forage, creating longer periods when the stomach is empty. Diets excessive in grain and insufficient in forage fail to stimulate adequate saliva production, which naturally buffers stomach acid. The quality and digestibility of forage affects buffering capacity, with excellent-quality hay providing better protection than poor-quality forage.

Exercise intensity and training regimens influence ulcer development substantially, with intense training schedules creating multiple risk factors. Exercise itself increases stomach acid production, making training on a full stomach more problematic than training in a fasted state. However, training with empty stomach creates periods of acid exposure without protective forage buffering. The stress of competition and high-intensity exercise creates cortisol elevation that increases acid production and decreases protective mucus production.

Stress represents a major contributor to ulcer development, with horses subjected to significant psychological or physical stress showing elevated cortisol levels that increase stomach acid secretion and decrease protective mechanisms. Transportation, changes in management, social disruption, competitive stress, and environmental changes all create stress that increases ulcer risk. Horses with anxious dispositions or those sensitive to environmental changes show higher predisposition to stress-related ulcers.

NSAID use, particularly excessive or prolonged use, damages the stomach's protective lining and predisposes to ulcer development. Phenylbutazone commonly used for pain and lameness management can cause gastric and colonic ulcers with chronic use. The risk increases with higher doses and longer duration of treatment. Horses receiving NSAIDs for pain management from other conditions face elevated ulcer risk, making preventive approaches important when NSAID use is necessary.

Individual predisposition based on genetics or physiologic characteristics influences ulcer development independent of management factors. Some horses develop severe ulcers with apparently reasonable management while others remain free of ulcers despite seemingly poor risk profiles. Foals show particularly high ulcer incidence, with stress, separation, and rapid diet changes during weaning precipitating ulcer development.

Competition type influences ulcer risk, with racing, eventing, and endurance horses showing particularly high incidence due to combined stress, intense training, and frequent transportation. Intense aerobic exercise appears to increase gastric acid production and predispose to ulcers more than less strenuous activities. The physiologic demands of competition combined with the stress of competition create multiple risk factors operating simultaneously.

Many horses with gastric ulcers show no obvious clinical signs, making prevention particularly important since horses with subclinical ulceration may show nothing beyond subtle behavior changes that owners fail to recognize as abnormal. Subclinical ulcers cause measurable performance decrements that manifest as reduced competitive results without obvious illness signs. This silent nature makes prevention essential for maintaining performance rather than waiting for clinical signs to develop.

Appetite changes represent an early sign of gastric ulceration, with affected horses showing decreased appetite, selective eating, or refusal of certain foods. Some horses show appetite sensitivity to rough or spiky hay that irritates the stomach lining. Horses may show reluctance to eat shortly after feeding, suggesting stomach discomfort after feeding. Appetite changes are sometimes subtle, noticed only by handlers who know the individual horse well.

Water intake changes sometimes accompany gastric ulcers, with some horses drinking excessively while others show decreased water intake. Excessive drinking may represent an attempt to dilute stomach acid. Some horses show preference for cold water over warm water or vice versa, potentially reflecting stomach discomfort. Drinking patterns should be observed as they sometimes provide clues about digestive discomfort.

Behavior changes including irritability, aggression, or unusual attitude alterations sometimes accompany ulceration. Some horses become difficult to handle, touchy about grooming or saddling around the girth area, or show sudden behavior changes without apparent cause. These behavior changes are often misinterpreted as training issues or temperament problems when they actually represent pain responses from stomach ulceration.

Colic-like signs including abdominal pain, obvious discomfort, or rolling occur with severe gastric ulcers or more commonly with colonic ulcers. Horses with mild gastric ulceration rarely show obvious pain, but those with significant ulceration show clear signs of abdominal discomfort. Frequency of low-grade colic episodes without apparent cause should raise suspicion of underlying ulceration.

Performance decrements including reduced exercise tolerance, reluctance to work, or inability to maintain previous training intensity can result from gastric or colonic ulcers. Horses that previously performed well may show sudden or gradual performance decline without lameness or other obvious causes. Jumping or cross-country athletes sometimes refuse jumps or show refusal behavior associated with ulcer-related discomfort. Racing horses show dropped claims or slower times without apparent training changes.

Digestive inefficiency manifesting as weight loss or poor weight maintenance can result from ulcers that reduce feed intake or interfere with digestive processes. Horses fail to maintain weight despite adequate feed intake when ulcers reduce digestive efficiency. Poor hair coat quality or general appearance of unthriftiness accompanies poor feed utilization in some cases.

Fecal changes including loose stool or occasional diarrhea sometimes accompany colonic ulceration or severe gastric disease. However, most horses with gastric ulcers show normal defecation despite significant ulceration, making normal fecal character an unreliable indicator.

Gastroscopic examination remains the definitive diagnostic method for gastric ulcers, allowing direct visualization of the stomach lining and identification of ulceration severity. The scope passes through the nose into the stomach, requiring sedation and careful technique. Video recording allows documentation of ulcers and baseline comparison with future examinations. Gastroscopy provides definitive diagnosis and helps differentiate between gastric and other causes of signs.

Practical diagnosis often relies on response to empiric treatment, with horses showing suspected ulcers receiving treatment and being reassessed for improvement. If performance improves, appetite returns, and behavior normalizes with ulcer treatment, presumptive diagnosis of gastric ulcers is supported. This approach is practical when gastroscopy is unavailable or prohibitively expensive.

Clinical suspicion based on history, signs, and risk factors supports diagnostic reasoning even without gastroscopic confirmation. High-risk horses showing compatible signs warrant preventive treatment even without confirmed diagnosis. Performance horses, competition animals, and those subjected to obvious stressors should be considered candidates for preventive approaches if they show any compatible signs.

Prevention is substantially more practical and cost-effective than treating developed ulcers, making prevention the primary approach to managing this common problem. Prevention strategies address multiple mechanisms: increasing stomach buffering by maintaining more consistent forage intake, reducing acid production through stress management, reducing empty stomach time through frequent feeding, and when necessary, using medication to reduce acid production.

Dietary prevention focuses on maximizing forage intake and maintaining a more natural feeding pattern. Providing free-choice hay maintains constant stomach fill and provides continuous buffering. High-quality legume hay provides better buffering than grass hay. Minimizing grain and concentrate feeding reduces the stimulus for large acid production and maintains longer digestion time. Some horses benefit from alfalfa-based diets that provide superior acid-buffering capacity.

Feeding management involves frequent small meals rather than large meals, with ideally unlimited hay access. If unlimited hay is not possible, feeding hay at regular intervals throughout the day and evening approaches more natural feeding patterns. Soaking hay may improve palatability and digestibility for some horses. Adding chopped forage or chaff to concentrate meals slows gastric emptying and provides more complete stomach buffering.

Stress management through consistent routines, minimal unnecessary transportation, and social stability supports acid reduction and protective mechanism enhancement. Allowing turnout with compatible herd mates when possible provides social enrichment and more natural movement patterns. Minimizing environmental changes and maintaining consistent handling reduces cortisol elevation and associated acid production.

Exercise management involves avoiding intense exercise on full stomach while also avoiding extended empty stomach periods before work. Allowing adequate time for gastric emptying before intense exercise reduces exercise-related acid splashing on the stomach lining. Feeding forage before and after exercise provides buffering before activity and replenishment after activity.

Preventive medication using proton pump inhibitors or H2 blockers reduces stomach acid production in high-risk situations. Omeprazole is commonly used for both treatment and prevention, with chronic administration in high-risk horses substantially reducing ulcer development and recurrence. Cost of preventive medication must be weighed against risk of ulcer development in individual horses.

Long-term management of ulcer prevention requires consistent implementation of multiple strategies addressing different causative mechanisms simultaneously. Single interventions rarely achieve complete prevention in high-risk horses, making comprehensive approach necessary. Combining dietary management, stress reduction, exercise modifications, and when appropriate, medication provides the best protection.

Daily management consistency supports prevention, with regular feeding times, consistent exercise routines, and stable social environments reducing ulcer risk. Horses thrive on predictable routines, and the consistency itself reduces stress-related acid production independent of specific management details. Changes to routine should be minimized when possible, and necessary changes should be implemented gradually when feasible.

Nutrition monitoring ensures that dietary modifications are being successfully implemented and that horses are maintaining appropriate body weight and condition. Regular assessment of hay quality and consumption rates confirms that forage intake goals are being achieved. Monitoring for subtle appetite changes detects early signs of developing problems before serious ulceration develops.

Competition or training management may require modification for horses with ulcer history or high ulcer risk. Training intensity should be adjusted to support prevention rather than pushed to maximums if ulceration risk is high. Competition frequency might be reduced in some cases if horses show consistent ulcer recurrence. Some horses may require medication during heavy competition or training seasons.

Transportation management becomes important for competition horses or those traveling frequently. Reducing transport duration when possible, providing hay during transport, and allowing rest periods during long distances reduce stress and maintain forage intake during transport-induced ulcer risk periods.

Monitoring response to preventive strategies includes observation of appetite, attitude, behavior, and performance trends over time. Subtle improvements in any of these parameters suggest prevention is succeeding. Gradual decline in any area might indicate development of ulcers despite prevention, warranting intensification of prevention strategies or investigation for other causes.

Seasonal adjustments may be necessary, with some horses showing higher ulcer risk during competition season or training intensity peaks. Preventive medication might be intensified during these periods. Attention to forage availability during winter when horses may have reduced access to fresh pasture supports prevention during this season.

Prevention strategies should be individualized based on risk factors specific to each horse, with high-risk horses receiving more intensive intervention. Young horses, performance horses, horses receiving NSAIDs, and horses subjected to significant stress warrant proactive prevention. Even horses with lower apparent risk benefit from basic preventive approaches including adequate forage, consistent feeding, and stress reduction.

Forage-based nutrition forms the foundation of all ulcer prevention strategies, with unlimited or near-unlimited forage access representing the single most important management modification for most horses. Owners reluctant to implement dietary changes should understand that forage provision is the most cost-effective and simplest intervention available. Even modest increases in forage and reductions in concentrate feeding help prevention substantially.

Stress reduction through consistent management, allowing social interaction, and minimizing unnecessary changes supports acid reduction independent of dietary modification. While some stress is unavoidable in performance animals, efforts to minimize psychological stress reduce ulcer risk. Providing turnout opportunities, consistent handling, and social companionship all contribute to stress reduction.

NSAID use requires careful consideration in horses with ulcer predisposition or confirmed history. Using NSAIDs only when necessary, at minimum effective doses, and for shortest possible duration reduces ulcer risk. Alternatives to NSAIDs should be considered when possible. If NSAIDs are necessary in ulcer-prone horses, concurrent preventive medication with proton pump inhibitors should be strongly considered.

Preventive medication may be warranted in specific situations including intensive training periods, competition seasons, or for individual horses showing consistent ulcer recurrence despite other preventive measures. The decision to use preventive medication should be based on individual risk assessment and the cost-benefit analysis specific to each horse and owner situation.

Prognosis for prevention in most horses is excellent, with consistent implementation of preventive strategies preventing ulcer development or reducing recurrence substantially. Horses managed with optimal preventive approaches show dramatic improvements in appetite, attitude, and performance. Long-term prevention maintaining ulcer-free status is achievable for most horses with committed implementation of preventive strategies. The investment in prevention during early stages of horses' careers or performance often prevents serious problems and expensive treatment later.