There’s talk around the barn. One of the horses was recently scoped and had ulcers. But is he the only one? You wonder if your horse may have ulcers too.
Are ulcers common?
Yes. They are very common. They occur in horses in all disciplines, pleasure horses, and even retired pasture horses. There have been many published research articles that have tried to measure the prevalence of ulcers. Those numbers range anywhere from 7% to 100%, depending on the horse population studied.
◆︎ What are some of the signs that a horse exhibits when they have ulcers?
Behavioral changes compared to previously. Examples include aggressive behavior under saddle and/or an irritable attitude.
Body condition changes. Has your horse had weight loss, poor appetite, loose manure, acute colic or mild persistent colic?
Change in performance. Has your horse had poor performance, decreased performance or a reluctance to work?
There are also horses with ulcers that display no visible symptoms that we can detect.
◆︎ The parts to the stomach:
➡ Upper portion (squamous region)
The upper portion (the squamous region) has tissue similar to the esophagus. It does not create acid on its own. It is very sensitive to the effects of acid. It does not have cells that are mucus-secreting, nor those that secrete a bicarbonate buffer. Its main protection is from a fibrous mat of forage that sits on top the gastric juices, protecting the upper portion from splashes.
➡ Lower portion (glandular region)
The lower portion is designed to withstand stomach acids. The cells in that region secrete digestive proteins, mucus and bicarbonate.The mucus is very thick and viscoelastic. Together with the bicarb, it helps protect the stomach lining from the acid.
➡ Fibrous mat
A fibrous mat composed of forage sits on top the acid and helps keep the acid from splashing up onto the sensitive upper
portion.
◆︎ So how does that impact ulcers?
➡ Ulcers in the squamous region:
Because the squamous region relies on the fibrous mat for protection from the acid, it is very common for ulcers to occur in this area. This is usually caused by “Acid splash”. It’s common when a horse exercises before having at least a little snack. It is estimated that 60-90% of the ulcers occur in this area.
➡ Ulcers in the glandular region:
Despite the protective mucus, some horses develop ulcers in the glandular region, which may be difficult to heal. Ulcers in this area are rarely caused by too much acid, but instead is caused by a failure to produce sufficient mucus and bicarb. Common reasons include:
☛Prolonged NSAID use
☛High stress levels. This could include intense exercise, frequent travel or herd instability, social isolation, or fear of predation.
☛Low forage intake
Glandular ulcers can occur in up to 60% of a specific population. These are usually more difficult to heal.
◆︎ How to treat ulcers:
Once a veterinarian diagnoses ulcers, he/she will prescribe the appropriate drug, such as omeprazole. Ulcers in the squamous portion can heal in about a month on omeprazole. However, if the ulcers occur in the glandular portion, it is common for it to take 40-60 days or more to heal.
Omeprazole is a proton pump inhibitor. It reduces the acid. However, it doesn't have a mechanism to encourage the re-establishment of the mucus layer.
◆︎ Supplementation:
As a horse owner, you can nutritionally support your horse with ulcers using Equine Ulcer Support. Equine Ulcer Support contains high molecular weight hyaluronic acid and beta glucans. It is an affordable option for the nutritional support of ulcers.
We do the best that we can for our horses. To do that, it's important to be aware of ulcers in horses.
Disclaimer: Statements regarding dietary supplements have not been evaluated by the FDA and are not intended to diagnose, treat, cure, or prevent any disease or health condition.
©Joan Kulifay, MSc. 2026