Ulcers in Horses: Symptoms & Causes
Some horses perform well on the outside while struggling quietly on the inside. Changes in behavior, energy, or appetite are often explained away as mood or training issues. But what if those signs point to something deeper? Gastric ulcers are common in horses, yet they often go undetected. The condition can affect everything from attitude to performance. Understanding the factors behind their development may shape how owners respond when something feels off. It may also help prevent more serious complications over time.
What Are Equine Ulcers?
Equine ulcers are sores that develop along the lining of a horse’s stomach or intestinal tract. These sores form when the protective lining becomes damaged by prolonged exposure to stomach acid. Unlike humans, horses produce stomach acid continuously, even when they are not eating. If a horse goes too long without forage or experiences frequent stress, that acid can begin to irritate the stomach wall.
Ulcers can vary in severity. Some may cause only mild discomfort, while others interfere with appetite, mood, or physical performance. Although often associated with competition horses, ulcers can affect horses of any age, breed, or workload. Even those kept in relaxed environments may be at risk if their feeding schedule or routine lacks consistency.
Understanding how ulcers form is the first step toward recognizing them early. Left unaddressed, they can lead to more serious health issues, including weight loss, chronic discomfort, and decreased quality of life.
Common Types of Ulcers in Horses
Ulcers in horses can develop in different parts of the digestive tract. Each type has distinct characteristics, but all can impact a horse’s comfort, behavior, and overall health. Knowing where ulcers form helps determine how they present and how treatment should be approached based on location and severity.
The most common types include:
Gastric Ulcers (EGUS):
These occur in the stomach, often in the squamous (upper) region. They’re linked to extended periods without forage or frequent travel, training, or stall confinement.
Glandular Ulcers:
These affect the lower part of the stomach and are associated more with stress and long-term inflammation than with feeding patterns.
Colonic Ulcers (Right Dorsal Colitis):
These appear in the large intestine and may be connected to NSAID use, dehydration, or chronic stress. Symptoms can be harder to detect.
While these ulcers differ in location and cause, they often share overlapping signs. Recognizing those signs early can help reduce discomfort and avoid complications over time.
Recognizing the Symptoms of Ulcers in Horses
Ulcers often go unnoticed in their early stages because the signs can be subtle or mistaken for training issues. Horses may continue to eat and perform, but still show signs of discomfort. Paying close attention to even small behavioral changes can help identify a problem before it worsens and affects overall well-being.
Common symptoms of ulcers in horses include:
- Decreased appetite or reluctance to finish meals
- Weight loss despite normal feeding
- Irritability, especially when being groomed or saddled
- Resistance under the saddle or changes in willingness to work
- Teeth grinding or frequent yawning
- Dull coat or poor body condition
- Frequent stretching, lying down, or signs of mild colic
These signs may appear alone or in combination, and their intensity can vary. Some horses may show only one or two mild symptoms, while others display more obvious behavioral changes. The key is noticing what’s normal for your horse and spotting the differences when they begin to shift over time.
What Causes Ulcers in Horses?
Ulcers are typically caused by an imbalance between stomach acid production and the natural defenses that protect the digestive lining. Horses produce gastric acid constantly, even when they aren’t eating. In a natural setting, grazing throughout the day helps buffer this acid. Modern feeding routines, stress, and training schedules can interrupt that balance.
Long gaps between meals, limited turnout, high-concentrate diets, and frequent travel all contribute to ulcer development. Horses that are stalled for long periods or placed under physical or mental pressure are especially at risk. Use of non-steroidal anti-inflammatory drugs (NSAIDs) over extended periods can also damage the protective lining of the stomach or colon.
Because ulcers in horses' signs and symptoms often appear gradually, it’s easy to overlook the impact of these everyday stressors. But repeated exposure to them increases the likelihood of developing digestive discomfort or more serious complications. Identifying and adjusting these risk factors early can help create better conditions for digestive health.
Horse digestive supplements like probiotics or buffering agents may help reduce the impact of acid exposure during long gaps between meals.
Risk Factors That Increase Ulcer Development
Some horses are more prone to ulcers due to how they’re managed, trained, or housed. While any horse can develop digestive ulcers, certain conditions raise the likelihood. Recognizing these risk factors helps owners take preventive steps before signs of discomfort appear or performance begins to change.
Common risk factors include:
- Infrequent feeding or long periods without forage
- High-grain, low-fiber diets that leave the stomach unbuffered
- Intense training schedules or frequent competition
- Extended stall confinement without regular turnout
- Trailering, travel, or unfamiliar environments
- Frequent use of NSAIDs or medications that affect the gut lining
- Sudden changes in routine, herd dynamics, or feed
These factors create stress in the digestive system or increase exposure to acid, both of which can wear down the protective lining. Even subtle changes, like a shorter turnout schedule or skipped meal, can shift the balance. Addressing these conditions early may limit the chance of ulcers becoming a recurring and costly issue.
Adding high-quality equine supplements can support digestive function and overall balance, especially in horses exposed to these common stressors.
When to Contact Your Veterinarian
If you notice behavioral shifts, appetite changes, or signs of discomfort that don’t resolve quickly, it may be time to involve your veterinarian. Many horses live with ulcers for extended periods before receiving treatment, simply because the symptoms are easy to overlook or misinterpret.
Some symptoms of ulcers in horses, such as girthiness, irritability, or mild weight loss, are often mistaken for training resistance or poor temperament. When these issues persist or appear alongside changes in performance, it’s important to consider the possibility of an underlying digestive issue. Diagnostic tools like gastroscopy may be recommended to confirm the presence and severity of ulcers.
Early intervention can lead to faster relief and a more comfortable recovery process. Working closely with your vet also helps shape a treatment plan that fits your horse’s needs. Timely care helps prevent ulcers from progressing and supports better long-term health outcomes.
If your horse is diagnosed with ulcers, PetPawsRx provides online access to trusted prescription treatments and digestive health products designed for long-term care.
