Q: My 10-year-old mare had colic surgery a few months ago and developed gastric ulcers during her recovery. What advice do you have for managing her digestive issues going forward?

A:  Recovery from colic surgery is difficult enough without the addition of ulcers. Stress can predispose a horse to developing gastric ulcers, and surgery is definitely stressful for any animal.

A horse’s stomach is divided into two parts. The glandular region, or the lower part, continually secretes acid. It is somewhat protected from ulceration because the cells in this region also secrete mucus, which forms a protective layer. The upper portion of the stomach is called the squamous region. The cells in this region don’t produce acid or mucus, but acid from the lower region can reach the upper region and cause ulcers to form.

Not all horses with ulcers show outward signs or, when they do, they’re subtle. Some signs you might observe include poor appetite, poor hair coat, poor performance, lying down frequently, teeth-grinding, and changes in attitude. Some horses might attempt to lie on their backs because it appears to provide relief from the ulcer pain.

The only way to definitively diagnose ulcers is having a veterinarian perform a gastroscopy on your horse with an endoscope, which is a type of camera inserted into the stomach through the nostril. If your horse was diagnosed with ulcers, she was likely prescribed medication, such as omeprazole. You should also work with your veterinarian and an equine nutritionist to make modifications to your horse’s diet to help prevent ulcers in the future.

Horses produce acid from the glandular region continuously. So, the goal of dietary management is to buffer acid production. A horse’s saliva contains bicarbonate, which helps buffer this acid, but horses only produce saliva when they are chewing. If you feed your horse some form of concentrate, consider higher fat and lower grain options, and divide rations into multiple small meals. Smaller meals will help the horse produce less acid.

Good-quality hay is vital to preventing ulcer development in at-risk horses. A small amount of legume, such as alfalfa, might be beneficial because of its higher calcium content. Forage requires more chewing than concentrates, so the horse will produce more saliva. In addition, forage will float and form a “mat” on top of the stomach contents, which will provide additional protection against acid reaching the squamous part of the stomach.

You can also implement management practices that can help prevent ulcers from forming. The goal is to decrease your horse’s stress levels as much as possible. For most horses, having some turnout time, especially with other horses, can reduce stress levels. Maintaining a consistent routine, such as feeding time each day, can also reduce stress. Make sure your horse always has hay available to her when she is traveling and at competitions, because chewing forage will help reduce acid buildup in the stomach.

These diet and management recommendations can help reduce the incidence of gastric ulcers in your mare. An additional benefit is these recommendations should also decrease the incidence of colic. Keep an eye out for any behavioral changes that might indicate ulcers are forming and be proactive. If you have any concerns about ulcers forming, ask your veterinarian to do an examination and possibly an endoscopy for diagnosis.