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.


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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 such as lipopolysaccharide (LPS). [7]

The ensuing immune response is one reason why high-grain diets can cause systemic issues such as laminitis and insulin resistance.

High-grain diets should be avoided when possible to support a healthy digestive system and support the horse’s overall metabolic health.

If your horse is fed grains, it is recommended to spread the amount over frequent, small meals rather than one or two large meals per day. This feeding regime will help minimize starch overload in the hindgut and decrease VFA production in the stomach.


4) Feed a High-Quality Hay

Feeding a high-quality hay is critical for your horse’s digestive health and overall well-being.

Providing adequate fibre, which has a prebiotic effect, will support gut health and microbial fermentation.

Hay typically contains fewer simple carbohydrates than grain resulting in much lower VFA production in the stomach.

Type of hay should be considered as different hays have different nutrient compositions.

Alfalfa-hay is a good choice for reducing ulcer risk in horses that require an energy-dense diet. It has a buffering effect in the stomach due to its higher protein and calcium content. [9]

Horses fed alfalfa-hay had a healthy stomach pH and lower number and severity of gastric ulcers compared to bromegrass hay. [9]

Alfalfa is also a good energy source and can eliminate the need for grains and concentrates in the diet. However, alfalfa may be too nutrient-dense for sedentary horses, which can contribute to obesity and the development of equine metabolic syndrome (EMS).

We recommend completing a hay analysis to ensure your horse is receiving the right hay to match its needs.


5) Evaluate Your Horse’s Diet for Protein and Fats

Starches and sugars are well-studied for their effects on ulcers in horses. However, proteins and fats can also play a role in gut health.

The higher protein and calcium content of alfalfa hay help to buffer volatile fatty acids produced in the stomach when horses consume grain. [10]

Sporting horses typically fed grain to meet their energy needs can be fed alfalfa hay to provide additional energy and support gastric health.

It is recommended to feed horses alfalfa hay before exercise and to avoid exercising on an empty stomach. Alfalfa also forms a fibrous barrier that helps protect the squamous region from acid splashing during exercise.

Dietary fat should be considered as an alternative energy source for performance horses. Fat sources like flax oil, camelina oil, or Mad Barn’s w-3 Oil can be used instead of grains to meet the horse’s energy needs while minimizing the risk of ulcers.

Submit your horse’s diet for a complementary consultation with our equine nutritionists to learn how different feed options can be used to support your horse’s individual needs.


6) Nutritional Supplements for Gut health

Natural dietary supplements can be an effective way to enhance your horse’s feeding program and promote gastrointestinal health.

There are many well-researched options to choose from. Some supplements are beneficial for preventing gastric or hindgut ulcers while others support overall digestive health.

Options for supplements to reduce ulcer risk include:


If you are considering adding a supplement to your horses diet, Mad Barn’s Visceral+ is a pelleted supplement recommended by veterinarians.

Visceral+ provides nutritional support for your horse’s digestive system, supporting gastric and hindgut health. Visceral+ also supports immune function.


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  • Our best-selling supplement
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Gut health supplements can support a healthy digestive tract and reduce risk factors for ulcers. We recommend that you consult with an equine nutritionist and/or your horse’s veterinarian to learn more.


7) Prevent Rebound When Treating Ulcers

Omeprazole, the pharmaceutical ingredient in GastroGard and UlcerGard, is an effective treatment for ulcers. It works by inhibiting acid production in the stomach to increase gastric pH.

In the short term, this can promote the healing of ulcers. Once treatment stops, the stomach will start to produce acids again.

This can result in acid rebound and a recurrence of ulcers once treatment stops.[22].

Equine veterinarians know very well that the stomach responds with an overproduction of acids following treatment with acid inhibitors like omeprazole. This hyper-acidic environment can lead to ulcer rebound.

This is not to discourage treatment of ulcers with omeprazole. But we do encourage adopting strategies to prevent rebound.

Mad Barn’s Visceral+ has been clinically studied in horses treated with omeprazole.

In a research study, horses received GastroGard treatment for ulcers for 15 – 30 days after which Visceral+ was fed alongside treatment with GastroGard for another 30 days. All horses showed healing of ulcers with no rebound after treatment.

Ulcer rebound can also occur in your horse if the original root causes of ulceration have not been addressed. The strategies in this article can help you to minimize some of the most common risk factors for your horse.


8. Minimize the use of NSAIDs

Non-steroidal anti-inflammatory drugs (NSAIDs) are administered to horses to reduce pain and treat certain conditions.

Phenylbutazone (“bute”) is a common NSAID used for pain management in skeletal muscles. Firocoxib is more commonly used to reduce pain associated with osteoarthritis or bone injuries.

NSAID use may be necessary at times. When advised and monitored by a veterinarian, NSAIDs can benefit your horse.

However, outside of these circumstances, the use of NSAIDs should be limited.

NSAID use has been directly associated with increased ulcers in the digestive tract of horses. These ulcers occur in the squamous and glandular regions of the stomach, as well as the hindgut. [24]

By inhibiting prostaglandin synthesis, NSAIDs reduce mucous production. They may also lower gastric pH levels below the normal pH of 2.

In healthy adult horses, administering phenylbutazone negatively impacted the mucosal barrier of the gastrointestinal tract. This increased ulcers and reduced overall digestive health. [23]

Under the direct advisement of a veterinarian, NSAID administration can be beneficial. Aim to provide a low dose over the shortest amount of time possible. When able, avoid administering NSAIDs to your horse.


9) Reduce Your Horse’s Stress Level

Stress is a major contributor to the development of ulcers in both humans and horses.

Why? Stress elevates circulating levels of cortisol and other thyroid hormones. Short-term elevation in cortisol is not a health concern and can be a good thing.

However, ongoing stress causes chronically elevated cortisol levels which can decrease prostaglandin levels.

Prostaglandins are involved in mucous production in the gut.

In rats, high cortisol levels were not directly associated with ulcers. But the low prostaglandin levels that occurred in conjunction with high cortisol resulted in ulcers. [11]

In horses, there is significant evidence that stressors including high-intensity exercise, traveling, and environmental changes are associated with higher incidence of ulcers. [1]

Signs of Stress

Managing stress levels in your horse will depend on their individual needs and routine. The first step is to identify the signs of stress in your horse.

A veterinarian can measure cortisol levels in the blood and saliva and measure changes in heart rate to gauge stress levels. However, this is not always feasible.

Instead, keep an eye out for physiological and behavioural signs of stress including:

  • Cribbing, chewing, and biting
  • Wall kicking or stall walking
  • Excessive yawning
  • Bucking, bolting, rearing, or pawing
  • Trembling and/or elevated pulse
  • Diarrhea and excessive urination

Long-term stress can also lead to weight loss, poor digestive health, poor coat health, and a weakened immune system.

Common Stressors

Once you have determined whether your horse is experiencing stress, you can work to narrow down the stressor.

Common stressors in horses can include:

  • Stall confinement
  • Frequent high-intensity exercise bouts
  • Travelling
  • Imbalanced nutrition such as providing poor-quality hay
  • Lack of routine and/or feeding regime
  • Poor socialization
  • New environments
Stress can result in physiological responses that increase the risk of ulcers. When you have identified potential stressors in your horse’s management, the next step is to eliminate or minimize them as much as possible.

The following three strategies will focus on well-known stressors for horses and their impact on ulcers and digestive health.

10) Avoid Over-Exercising Your Horse

Excessive exercise is strongly associated with the development of ulcers in horses.

In observational studies, there is a higher prevalence of gastric ulcers in horses undergoing race training compared to non-working horses. [12]

Horses undergoing a high-intensity exercise regimen six times a week experienced high rates of ulceration. [13]

Racehorses exercised between five to seven days a week experienced a significant increase in ulcer development compared to horses exercised one to four times a week. [14]

Why is exercise a significant risk factor for ulcers? There are several possible reasons.

Exercise causes changes in gastric motility, which refers to the movement of food through the digestive tract.

Exercise increases pressure in the intra-abdominal region and compresses the stomach. This means that the squamous region of the stomach, which lacks protection from mucous, is more readily exposed to stomach acids. [15]

Furthermore, there is an increase in hydrochloric acid in the stomach during exercise. [16] These factors create an ideal environment for ulcers.

Exercise also negatively impacts the digestibility of nutrients, although this should be further evaluated. [17]

There is a strong link between intense exercise and ulcers. Reduce exercise duration, frequency, and intensity where possible. Avoiding exercise on an empty stomach is also crucial for minimizing ulcer risk.


11) Reduce Travel

Travel is a known stressor for horses. Transportation greatly increases the risk of equine ulcers. [2]

However, it is difficult to isolate the magnitude of travel as a risk factor. Typically, traveling horses also compete or perform. It is unclear which activity poses a greater risk.

Transportation of horses exposes them to unfamiliar environments and new social groups which can cause stress.

During transport, horses typically have reduced water and food intake. Both of these are risk factors for ulcer development.

We recommend minimizing transportation of your horse when possible. When travel is necessary, ensure there is adequate food and water available.


12) Avoid Stall Confinement

The last strategy to reduce ulcer risk for your horse is to avoid stall confinement for long periods of time.

When horses are confined to their stalls, they have less time to graze on pasture. This will limit the amount of food passing through their digestive system.

Even when hay is provided free-choice, horses confined to their stalls consume less. This increases the time between meals. [18]

Stall confinement can also impact water intake for similar reasons.

In one study, stall confinement resulted in ten out of eleven horses developing ulcers. [19]

Increase your horse’s turnout and minimize their time in the stall. Greater pasture time will also increase grazing which can reduce ulcer risk for your horse.


Signs and Symptoms of Ulcers

There are many different signs and symptoms of ulcers in horses.

Ulcers can cause significant pain and discomfort for your horse. They can also contribute to:

  • Poor appetite
  • Chronic diarrhea
  • Weight loss and/or poor body condition
  • Reduced nutrient absorption
  • Increased aggression
  • Reduced performance

This list of signs and symptoms is not exhaustive.

In this article, we have provided many general strategies to consider for preventing ulcers throughout the digestive system.

The best strategies to use will depend on whether your horse is dealing with gastric ulcers or hindgut ulcers. You can read more about gastric ulcers and hindgut ulcers individually at these links.

If you believe your horse is affected by ulcers, please contact your veterinarian to decide on the best treatment plan for your horse.

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  2. Buchanan B.R. & Andrews F.M. Treatment and prevention of equine gastric ulcer syndrome. Vet Clin. 2003.
  3. Bass L. et al. Effects of feeding frequency using a commercial automated feeding device on gastric ulceration in exercised Quarter horses. J Equine Vet Sci. 2018.
  4. Murray M.J. Grodinsky C. The effects of famotidine, rantidine and magnesium hydroxide/aluminium hydroxide on gastric fluid pH in adult horses. Equine Vet J Suppl. 1992.
  5. Nadeau J.A. et al. Effects of hydrochloric, acetic, butyric, and propionic aicds on pathogenesis of ulcers in the nonglandular portion of the stomach of horses.Am J Vet Res. 2003.
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  14. Sykes B.W. et al. Management factors and clinical implications of glandular and squamous gastric disease in horses. J Vet Intern Med. 2018.
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  16. Furr M. & Kronfeld T.D. The Effect of exercise training on serum gastrin responses in the horse. Cornell Vet. 1994.
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  19. Murray M.J. & Eichorn E.S. Effects of intermittent feed deprivation, intermittent feed deprivation with rantidine administration, and stall confinement with ad libitum access to hay on gastric ulceration in horses. Am J Vet Res. 1996.
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