What can you do to prevent ulcers from developing in your horse? Equine ulcers are all too common, with studies showing that up to 90% of horses will be affected by ulcers in their lifetime.

Stomach ulcers, also known as Equine Gastric Ulcer Syndrome (EGUS), are most common in horses. But ulcers can occur along the entire digestive tract.

When ulcers develop in the hindgut, they are referred to as Right Dorsal Colitis (RDC) or colonic ulcers.

There are multiple distinct causes of ulcers in horses. When a horse develops gastric ulcers, it is usually due to several interacting risk factors including diet, exposure to stress, workload, environment, and more.

Unfortunately, recurrence is very common after treatment unless the root cause of the problem is addressed. This is why it’s important to look at your horse’s overall routine and feeding program to identify ways to reduce the risk of recurrence.

There are many ways to naturally reduce the risk of equine ulcers and support your horse’s gut health. With a few simple changes, you can significantly decrease the likelihood of ulcers and other ongoing digestive problems.

In this article, we will discuss natural strategies you can implement to prevent the potential onset of ulcers in your horse.

Ulcers in Horses: What are They?

Ulcers are painful lesions that occur along the gastrointestinal tract of the horse. [1] They develop when stomach acid causes erosion of cells and inflammation in the stomach wall.

The stomach of the horse continuously produces acid such as hydrochloric acid (HCl) whether there is food to digest or not. This makes the stomach a highly acidic environment which is a major risk factor for ulcer development.

The upper squamous region of the stomach (including the oesophagus) is the most at risk for ulceration with up to 80% of all ulcers located here.

This region of the stomach cannot produce mucous to line and protect the stomach wall, leaving it susceptible to ulcer risk factors such as acids.

Instead of mucous, horses rely on food and saliva to buffer and protect the squamous region of the stomach. However, when the horse’s stomach is empty, these defences are inactive and ulceration can occur.

The glandular region of the stomach is also exposed to stomach acid. However, it produces mucous and bicarbonate to buffer acids which protects the lining of this area. [20]

Ulcers are sores that develop in the lining of the digestive tract when cells are eroded by gastric acids. They are most prevalent in squamous the region of the stomach.


Stomach Ulcers Location in Horses

Ulcers can also occur in the hindgut, consisting of the colon and cecum. Hindgut or colonic ulcers are less common than EGUS, but can be just as detrimental.

Negative Impact of Ulcers

In addition to discomfort, ulcers can cause a serious negative impact on a horse’s well-being and contribute to the following:

While there are many effective treatment options for ulcers these are not without consequences. On top of the high cost of drugs like omeprazole, there is also a high rate of recurrence in horses when they finish a course of medication.

Preventing or minimizing potential risks for ulcers can reduce the frequency and/or severity of ulcers in your horse.

Ulcers can negatively impact your horse’s overall well-being by interfering with digestion and reducing nutrient uptake from feed.


Mad About Horses
Join Dr. Chris Mortensen, PhD on an exciting adventure into the story of the horse and learn how we can make the world a better place for all equines.
Apple Podcasts Spotify Youtube
Mad Barn Equine Nutrition Consultants

12 Ways to Naturally Prevent Ulcers in Horses

Here we discuss the 12-best evidence-based natural strategies that can reduce the risk of ulcers in your horse.

1) Avoid Intermittent Feeding

Intermittent feeding means there are prolonged periods between meals where your horse’s stomach is empty. This increases the risk of ulcers developing.

In a natural environment, horses graze for up to 18 hours per day. Their stomachs are almost never empty which prevents ulcers from developing.

For this reason, it is important to provide food throughout the day for your horse. [2]

The continuous presence of feed in the stomach helps to keep gastric acid in the protected glandular region of the stomach. It also provides the squamous region with feed and saliva to buffer the acidic pH.

In fact, intermittent feeding is such a major risk factor for equine ulcers that fasting is used as a model to induce ulcers in research. In other words, if you do not feed your horse for a long enough period, ulcers are guaranteed to develop.

When compared to horses fed two meals per day, Quarter horses fed 20 meals throughout the day had lower prevalence of ulcers after 30 days. [3]

Some horse owners with easy-keepers and overweight horses worry about providing constant access to forages.

Slow feed hay nets are a good option to help extend the amount of time your horse spends feeding, keeping the stomach full for longer, without over-supplying calories.

Your horse should have access to food throughout the day, whether that means access to pasture or hay.


2) Provide Constant Water Access

Hydration is important for many aspects of equine well-being but particularly for digestive health. Intermittent water intake increases the risk of developing ulcers.

Research shows that horses without access to water in their paddock are 2.5 times more likely to develop ulcers compared to horses with constant water access. Gastric ulcers in this population were also more severe. [21]

Water intake helps to dilute gastric fluids, reducing the stomach’s acidity. Consumption of water also supports gut motility, which refers to the transportation of food through the gastrointestinal tract.

Providing water to your horse may be difficult during transportation or when travelling to competitions. It can also be harder to provide fresh water during the winter when freezing conditions can occur.

At times when consistent water access is not possible, the other tips mentioned in this article become increasingly more important to lower ulcer risk for your horse.

We recommend providing consistent access to water and feeding your horse free-choice loose salt to increase water intake.


3) Limit Grain Consumption

The composition of the diet can affect the digestive tract and may have a role in the development of equine ulcers.

High-grain diets increase the risk of ulcers for several reasons. Eating grain does not require much chewing and therefore does not produce significant saliva to buffer the stomach acid.

Grain also moves more rapidly through the stomach than forage, meaning the stomach is empty for longer periods.

Grain is typically added to equine diets as an energy source. Fermentation of simple carbohydrates in the hindgut produces volatile fatty acids (VFA) (acetate, propionate, and butyrate), which are absorbed and used as energy by the horse. [4]

Volatile fatty acids are the major energy source for the horse. High grain diets are often used by racing or performance horses because it provides dense energy.

However, high starch concentrations in the diet increases VFA which can reduce pH and form an acidic environment. [5] Over extended periods of time , this can cause hindgut acidosis which is a risk factor for hindgut ulcers.

This process is not limited to the hindgut. High-grain diets can also cause VFA production in the stomach, further reducing the pH and increasing the risk for ulcers.

Prolonged high-grain diets can have additional consequences. High grain diets (>20% of the diet) can decrease starch digestion in the small intestine by up to 58%. [6] This means that more starch will reach the hindgut and affect the microbial environment.


A negative shift in the hindgut microbial populations, known as dysbiosis, is common on high-grain diets. [8] This can lead to inflammation in the hindgut.

Dysbiosis can also increase the absorption of inflammatory bacterial products suc