Equine Gastric Ulcers: Causes, Symptoms, and Prevention


Sport horse develops gastric ulcers

The first thing that comes to mind whenever horse digestive problems are concerned is colic. However, one of the most common conditions affecting nearly all horses globally is gastric ulcers. According to a study by the American Veterinary Medical Association (AVMA), 58% of show horses are diagnosed with gastric ulcers. Racehorses, performance, endurance, and even pleasure horses are affected by gastric ulcers. Using revolutionary diagnostic tools, it is now possible to diagnose equine gastric ulcers with precision. However, gastric ulcers are one of the most common ailments affecting high-performance horses at an alarming rate.

horses graze to help neutralize acid in the stomach preventing ulcers

Why are horses prone to ulcers?

Gastric ulcers in horses are a direct result of the erosion of the stomach’s inner lining. This happens due to prolonged exposure to the acids produced in horse’s stomach. There is no specific age for this to happen and ulceration equally affects even foals.


Horses naturally graze throughout the day in wild and that continuous supply of hay or grass in the stomach helps to neutralize acidic secretions. High concentrate diets, stress and provision of low feeding time makes the inner linning of stomach prone to acidic secretions. A brief overview of equine digestive system can help to elaborate equine gastric ulcers.

Equine digestive system anatomy
Photo credit: SmartPak

Anatomy of the Equine Digestive System

The equine digestive system is divided into foregut and hindgut. The foregut consists of the mouth, esophagus, stomach, and small intestine. The small intestine makes its way to the hindgut which includes the caecum, colon, and rectum. A major portion of the horse feed is fermented in the hindgut with the help of bacteria, yeast, and protozoa.



equine stomach has non-glandular and glandular regions
Photo credit: SmartPak

Interestingly, horse’s stomach is further divided into two parts: the lower part is glandular that comprises two-third of the stomach where the acid is secreted. It has a thick protective mucosal covering that acts as a barrier for sensitive stomach tissues. Ulcers can be found here but they aren’t common. The upper part or non-glandular part, where the mixing of the stomach’s contents takes place, is more prone to acids due to its thin protective lining. It is the region where ulcers mostly occur.


Other than gastric ulcers another type is colonic ulcers. Colonic ulcers remain undiagnosed due to their vague signs, unavailability of sufficient diagnostic tools, and limited usage. It is vital to differentially diagnose colonic ulcers because medications for gastric ulcers do not work for colonic ulcers.


Causes of Ulcers in Horses

Equine gastric ulcer is a frequently occurring health condition faced by many horse owners, breeders, and caretakers and a variety of factors can play part in ulcer development. Following are some of the significant causes of gastric ulcers in horses:


1. Stress

Stress is by far the number one cause of gastric ulcers in the equines. Horses are less likely to eat when they are under stress.


Frank Andrews, a renowned equine medicine researcher, says that the major source of gastric ulcers is stress from training. When a horse is consistently under stress, chemical changes occur. Among other changes, stress increases the cortisol levels in the blood. This increase in cortisol level is similar to increased serum gastrin which increases the production of hydrochloric acid in the stomach. Further physical and environmental stressors include transport stress and stall confinement besides others.


exercising horses on lunge line

2. High exercise

Gastric ulcers can affect a horse at any age, but researchers have found that the condition occurs frequently in horses that perform athletic activities like racing, endurance, and show. Exercise increases the levels of acid production due to low grazing and decreases blood flow in the GI tract. Moreover, when horses exercise, the acid produced in the stomach splashes and exposes the upper, more vulnerable portion of the stomach to acidic environment.


3. Low grazing

A horse’s stomach produces a steady flow of acid round the clock which is required for digestion. This accounts for up to 9 gallons of acidic fluid per day even when the horse is not eating. Proper grazing, the acid is buffered by both the saliva and the feed. In boarding situations, horses are usually fed twice a day where the stomach is subjected to long periods without any feed to neutralize the acid’s effects.


4. High grain diet

Another key factor responsible for equine gastric ulcers is high grain diet. Grain produces high number of fatty acids which reduces pH.


5. Medicines

The chronic administration of some nonsteroidal anti-inflammatory drugs (NSAIDs) like Ketoprofen, Banamine, and Phenylbutazone hampers the production of the protective mucosal layer of the stomach and makes the stomach more prone to ulcers.


Signs and Symptoms of Equine Ulcers

A vast majority of horses have sub-clinical signs as they appear healthy. But there are subtle signs that can point towards an underlying health concern:

ulcers in equine stomach can cause pain
Photo credit: SmartPak
  • Loss in appetite and feed intake

  • Dull attitude and lethargy

  • Resistance to training and workout

  • Weight loss and anemia

  • Low-grade colic

  • Avoiding feed and preferring hay

  • Crib-biting and wind sucking

  • Excess salivation

  • Diarrhea

Besides these subtle signs, there are serious cases of equine gastric ulcers where the horse shows abdominal pain and/or grinding of his teeth. Some adults (and most young horses) are found on their backs as this position provides them comfort from severe gastric ulcers. Some will walk away from food when it first reaches their stomach.


Why do ulcers remain undiagnosed?

No matter how caring you are as a horse owner, your horse won’t come to tell you of his ulcers. The signs are subtle and this is why many times the ulcers remain undiagnosed. Rather they are mistaken for parasitism and colic.


Gastric ulcers can be diagnosed with the help of gastric endoscopy and gastroscopy. The procedure involves the placement of an endoscope in the stomach and viewing the surface. The procedure is relatively simple and gives maximum space for proper evaluation.


What is the prognosis for gastric ulcers?

The projection of diagnosis for affected horses is good and gastric ulcers are treatable. Their prevention is also possible by following simple management techniques. Most equines heal within a month of treatment.


How to Prevent Gastric Ulcers in Equines

Horse owners can utilize the following management techniques to prevent gastric ulcers:

  • Avoid or control the use of anti-inflammatory drugs. Use only medications approved by the FDA if there is no other option except administration, use safer medications like firocoxib, that too under the vet’s recommendations

  • Limit stressful situations like frequent transportation and intense training sessions.

  • If you choose to stall them, make sure they see and socialize with other horses and also have access to grazing.

  • Balance their grain and concentrates intake and provide them with sufficient hay. Whatever you choose to add or deduct from their diet, always ask for your veterinarian’s recommendations.

  • Don’t keep the animal off-feed for an extended duration and feed them frequently or provide sufficient grazing time.

  • Ensure round-the-clock access to clean water

  • Use 50-100 ml of corn or rapeseed oil twice daily to reduce the amount of stomach acid produced

  • Provide hay nets while traveling transportation for competitions and shows.

  • Avoid horse training and workout with an empty stomach.

preventing equine ulcers with red light therapy and photopuncture

Holistic Approach to Preventing Ulcers

As you look to provide the best care for your horse, you also may want a variety of options to help him. <