Corro Stories

Corro's Guide to Equine Gastric Ulcers

By Kimberlyn Beaudoin

Most horse owners have heard the phrase “gastric ulcers” before. Some of us may have had direct experience with them (they affect humans, too), and for others they may only be a lingering worry. Though gastric ulcers are a health hazard for our equines, there are several proactive precautions that owners can take to prevent them from happening. 

So, what are equine gastric ulcers? According to the American Association of Equine Practitioners (AAEP), equine gastric ulcers are defined as: “the result of the erosion of the lining of the stomach due to a prolonged exposure to the normal acid in the stomach. Unlike ulcers in humans, bacteria do not appear to cause equine gastric ulcers. Horses are designed to be grazers with regular intake of roughage. Since the horse’s stomach continually secretes acid, gastric ulcers can result when the horse is not eating regularly due to there being less feed to neutralize the acid.” 


Image by KTB Creative Group

A large number of horses with gastric ulcers aren’t particularly symptomatic. They express subtle changes in their behavior like lack of appetite, a foul attitude, “girthieness,” weight loss and/or dulling of their coat. Horses with more sever gastric ulcers may display poor athletic performance, or even colic. The trickiest part about equine ulcers is that they can’t be 100% diagnosed without a gastroscopy, which requires an endoscope. This process must be done on an empty stomach, and places a tube down the horse’s nostril and esophagus into the stomach.

The treatment of equine gastric ulcers varies on the severity of the patient but is all centered around decreasing the acid production in the stomach by altering and removing predisposing factors. It is recommended that horses in this situation have unlimited access to hay or other forage, and sometimes grain. Feeding horses frequently throughout the day helps to buffer the acid from the stomach lining, which in return helps to heal the painful ulcers. If the horse is under a lot of stress, it is in its best interest to be removed from said stressful situation, or reduce the stress by adjusting environmental factors. If the environmental issues are severe and the horse cannot be removed from the situation, medications may be advised. Additionally, there are a variety of supplements that can help reduce the continued risk of equine gastric ulcers. These supplements provide an extra coating to the lining of the stomach and help prevent recurring acid damage.

Image by Jean-Pierre Duretz from Pixabay

The ultimate goal is to prevent equine gastric ulcers from ever even occurring. How can one stay diligent in this department? There are a variety of precautions that can be taken to reduce the risk of your equine getting gastric ulcers. These preventative actions include:

- Create an action plan with your local veterinarian

- Feed several servings of forage per day

- Limit the amount of stress your equine is under on a regular basis

- Make sure that there is always access to fresh, clean water

- If you need to medicate before a big show or change in environment, check with your equine veterinarian and use products that are labeled specifically to prevent and/or treat equine gastric ulcers and approved by the FDA.

- Know your horse’s typical behavior! If they start to act aggressively or seem more lethargic than normal, contact your veterinarian

If you would like to learn more about equine gastric ulcers and how to prevent them, please visit the American Association of Equine Practitioners at, or consult your local large animal veterinarian. If your veterinarian recommends you use a supplement for your horse to prevent or treat gastric ulcers, check out Corro’s complete collection of ulcer supplements.

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