Reducing Ulcer Risk in Exercising Horses

By: Dr. Priska Darani, PhD

Gastric ulcers are all too common among exercising horses. Research suggests that 60-90% of all performance horses will experience ulcers at some point in their lifetime. Ulcers can result in harmful consequences for overall health, comfort, digestion and performance.

Ulcers are painful sores or lesions that can form throughout your horse’s gut but are most common in the stomach. They occur when the lining of the stomach or the intestines is exposed to digestive acids. Under normal circumstances, there is a mucous barrier that protects this tissue from gastric acids. However, if this barrier is eroded, the tissue can come into direct contact with the acid and sores can form.

Why are ulcers so prevalent in performance horses? Any time a horse is exercising, there is an increase in pressure in your horse’s abdomen. This can cause compression of the stomach and result in digestive juices being squeezed into the upper squamous region of the stomach. This part of the gastrointestinal tract (including the esophagus) is not able to produce mucous on its own and does not have a mucous barrier.

The squamous region of the stomach is where the majority of ulcers form. However, they can also occur throughout the digestive system including in the hindgut and colon. Ulcers that form in different parts of the gut tend to have different causes, but exercise is a major risk factor for all types of ulceration.

Preventing Ulcers in Exercising Horses

Given this situation, what can you do to reduce the risk of ulcers in your exercising horse?

Here are 5 principles to follow:

•   Never exercise your horse on an empty stomach.

Your horse’s stomach produces acid continuously whether there is food present or not. This is because horses evolved to eat many meals throughout the day. Food, as well as saliva that is produced when a horse chews, help to buffer digestive acids, reducing the acidity of the stomach.

When you exercise your horse with an empty stomach, there is nothing present to buffer the acid. Furthermore, exercise increases the production of hydrochloric acid in the stomach. This makes it more likely that ulcers will form given the inherent risks of exercise itself.

Always make sure your horse eats forage before exercising. Fibre in alfalfa hays is believed to help reduce the risk of acid splashing in the squamous region of the stomach during exercise.

•    Ensure Adequate Water Intake

An 1100 lb (500 kg) horse should drink 10 gallons of water per day to support optimal hydration and gut health. Research shows that digestive issues in horses are more common in the winter, which may be linked to inadequate water consumption.

Water reduces ulcer risk by diluting the acidity of digestive juices. It also promotes gut motility, which refers to the transit of food through the gut. It is important to give your horse access to water throughout the day and to provide free choice loose salt to encourage water intake.

Salt in the diet is important not only for meeting the horse’s sodium requirement but also to simulate thirst. Don’t just rely on a salt block, as horses often do not get enough sodium from salt blocks. Add 2 tablespoons (30 grams) of plain loose salt to your horse’s feed to support electrolyte balance and increase water intake. This is particularly important for horses in work as they will lose water through sweat.

•   Don’t Feed a High-Grain Diet

Many horse owners think that they need to feed grain to support the energy requirements of exercising horses. Modern research shows this isn’t the case. Excessive grain intake can cause a number of digestive problems for horses, including hindgut acidosis and increased ulcer risk.

Grain can increase the risk for gastric ulcers because it does not require much chewing and therefore does not produce much saliva, compared to consuming forage. Grain fermentation can begin in the stomach and produce acids that further lower the gastric pH. Too much starch in the diet can also result in changes to the microbial population within the hindgut, leading to more lactic-acid producing bacteria and a more acidic environment.

Researchers have demonstrated that feeding more than 2 kg of grain per day can double the risk of gastric ulcers in horses. Instead, opt for nutritionally-dense non-grain feed options that will better support your horse’s needs and reduce the cost of your feeding program.

•   Help to Minimize Stress

Horses engaged in intensive exercise or competition are naturally exposed to a number of known stressors in their routine. Changes in environment, transportation, changes in social grouping, stall confinement and training all are potential sources of stress for your horse.

This is such a major risk factor that ulcers can form in your horse within a week of starting a standard training program. The American Association of Equine Practitioners writes that, “Typical training and recreational showing have been shown to induce ulcers within a five- to seven- day period.”

Stress contributes to ulcers by increasing levels of circulating stress hormones such as cortisol and epinephrine (adrenaline). Over long periods of time, chronic high cortisol can interfere with the production of mucous in the gut, which is necessary for maintaining a protective barrier between the acidic environment and cells of the digestive tract. Stress also impedes wound healing and exercise recovery.

Keep an eye out for stereotypic behaviours and other signs of stress in your horse. Consider reducing their workload or changing their routine or social grouping if they seem stressed. Diet also plays a major role in minimizing stress. Identify nutrient deficiencies and consider feeding a ration balancer to ensure the diet is providing enough B-Vitamins and magnesium.

•   Increase your Horse’s Turnout

Stall confinement is one of the biggest known risk factors for gastric ulcers. One study found that ten out of eleven horses confined to their stalls developed ulcers.

It is important to give your horse lots of time outdoors to graze on pasture whenever possible. In particular, turnout with other horses appears to be protective against ulcers.

Increasing turnout will also help to promote species-appropriate foraging behaviours for your horse, leading to less time with an empty stomach. Even if you provide free-choice hay, horses that are confined to their stalls consume less food which can contribute to higher risk of ulcers.

What is your Horse’s Ulcer Risk?

Wondering what your horse’s ulcer risk is? Take Mad Barn’s quiz to find out and identify factors that could be increasing your horse’s risk profile.

If your horse has experienced ulcers in the past, recurrence is common unless the root causes are addressed. This quiz can help you identify practices that may be contributing to a higher risk for your horse.

Hopefully, implementing these strategies will help to keep your horse ulcer-free and healthy even while they are exercising. Should your horse develop ulcers, ask your veterinarian about feeding Mad Barn’s Visceral+ complete gut health supplement.

•   Clinically proven for ulcers
•   Restore integrity to gut lining
•   Prevent stomach upset recurrence
•   100% safe & natural

Visceral+ is a clinically studied gut health formula that is proven to work for horses with ulcers. Visceral+ is formulated with effective probiotics, prebiotics, amino acids, yeast cultures, natural herbs, and minerals that support intestinal barrier function and help to maintain stomach and hindgut health.

The health and wellness of your horse starts in the gut. Visceral+ provides complete nutritional support for your horse’s digestive system from stomach to colon, helping to maintain a balanced microbiome and support the immune system.

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