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5 Common Reasons for Ulcers in Horses & 3 Ways to Prevent Them

Published by Faith Hanan on July 15, 2024
5-common-causes-of-ulcers-in-horses

Last updated on October 8, 2024

5 Common Reasons for Ulcers in Horses & 3 Ways to Prevent Them

Here’s a fact that many of us horse owners don’t want to face: Ulcers in horses are one of the most prominent health issues that every horse owner faces at one time or another. Regardless of what event you compete in, or whether or not you compete at all, chances are good you will have to deal with an ulcer or two.  In fact, according to Pennsylvania State University’s extension office, stomach ulcers caused by ESGD (equine squamous gastric disease) are diagnosed in 11-90% of horses! Performance horses have the highest rate of 90-100%, but interestingly enough, pleasure horses (considered light exercise) still have a diagnosis rate of 11-59%. [1]

So why are ulcers such an issue in performance horses, especially racehorses? What can we do to help a horse with ulcers recover, and can we help our beloved four-legged partners avoid ulcers altogether? 

We are going to take a look at ulcers in horses from both a scientific perspective and a practical standpoint, as well as give you a few simple ways to help lessen the occurrence of ulcers. 

Understanding Ulcers in Horses

Due to the complicated nature of their digestive system, horses can get ulcers in different locations of their gut. The most common type of ulcer is in the foregut, specifically, the upper part of the stomach called the squamous section. The cells in this portion of the stomach do not secrete acid or protective mucous, leaving the stomach lining highly susceptible to acid damage. The damage to the lining can result in ulcers, called Equine Squamous Gastric Disease or ESGD. [2]

Ulcers in the hindgut are less common but can be highly damaging as they usually go undetected for longer because of the difficulty of diagnosis. Hindgut ulcers are generally caused by a disruption in the pH balance of the intestines, called hindgut acidosis. 

A drop in the pH and an increase in stomach acid hinder the production of the protective mucous lining the hindgut, allowing for ulcers to form. Studies show that prolonged use of non-steroidal anti-inflammatory drugs (NSAIDs) can also impede blood flow and mucous production in the hindgut. [3]

To avoid confusion, and keep this article as brief as possible, we will focus on gastric (stomach) ulcers as they are the most prevalent type of ulcer. But just know that poor foregut health can severely impact the health of your horse’s hindgut as well. To learn more about foregut/hindgut health, check out our blog from October 2023, The Role of the Foregut and Hindgut in the Horse’s Digestive System. 

5 Common Causes of Gastric Ulcers in Horses

It’s easy to accuse heavy exercise as the sole cause of ulcers in performance horses, but if that was the case then retired horses in the pasture wouldn’t suffer from them as well. While it’s true that heavily worked horses, most notably racehorses, have an extremely high number of diagnosed ulcers, nutrition &  feeding schedules, stress, and breeding can also play a role in the development of gastric ulcers. 

1. Nutrition & Feeding Schedules

Horses primarily kept in stalls without grazing access, have an increased rate of ulcer development. [4] This is due to the lack of forage in their stomachs absorbing the acid. Equine stomachs produce acid constantly, so when the horse is not grazing and putting fibrous plant material into their stomach, the acid has nothing to break down except for the lining of the stomach. 

In addition, when a horse salivates, it produces bicarbonate which neutralizes stomach acids. So without constant chewing, saliva is not being produced to break down the ever-present stomach acid. This means that horses in stalls or small paddocks that are fed larger meals twice a day are also at an increased risk for ulcers. Small, frequent feedings keep the stomach full and busy, even without 24/7 grazing access. A recent study has shown that even adding 1 extra feeding during the day dramatically reduces the risk of gastric ulcers. 

Grain feeds that are high in sugars and carbohydrates can also contribute to ulcer development. They lower the pH balance in the gut and become volatile fatty acids (VFAs) that can cause local acidification in the squamous portion of the stomach, creating ulcers. [5]

2. Stress Levels 

Much like in humans, chronic stress in horses can cause stomach ulcers (along with other health issues). Cortisol levels increase during periods of stress, which increases hydrochloric acid and throws off the gut’s pH balance, making the perfect environment for ulcers to occur. On top of high cortisol and acid levels, stressed horses will sometimes eat less and move more (like pacing), which contributes to higher stomach acid levels. [6]

A stressful situation can be many different things for horses. Remember, they are prey animals and their survival depends on being alert and ready to run at the drop of a hat. Being separated from their herd or companion, moving pastures/barns, change of schedule, traveling, injuries, and an increase in training can all trigger a stress response in a horse. 

3. Breeding & Temperament

Thoroughbreds and Standardbreds are, without a doubt, the two breeds with the highest rate of ulcer diagnosis with Warmbloods right behind them. According to an article from the online journal Animals, “Prevalences of 37–52%, 38–56% and 48% in Thoroughbred, Standardbred, and endurance race horses, respectively, while out of training have been reported. These increase up to 100%, 72–88% and 57–93% respectively when these same populations are in training.” [7]

It is still uncertain if this is because of the events they compete in (racing and endurance) or from a genetic predisposition, but it is safe to assume that if you have one of those breeds, that horse has a high risk of developing ulcers. 

Likewise, if you have a naturally anxious or high-strung horse, the chances of ulcer formation increases. This is because of the acid and cortisol production as mentioned in the above section.

4. Chronic Medication Use

Studies have shown that chronic use of NSAIDs (non-steroidal anti-inflammatory drugs) increases the chances of the horse developing ulcers. Drugs like Bute and Banamine (phenylbutazone and flunixin meglumine) are often over-used in the performance horse world and have been shown to restrict mucous production, leading to more acidic stomachs and damaged lining. This is especially true if the horse already has a history of Equine Gastric Ulcer Syndrome (EGUS). 

5. Heavy Exercise

It’s common practice in the horse racing industry to exercise/train horses hard, 5+ days a week, with very little food in their bellies(prior to exercise). A high workload (for any equine event) has a direct correlation with ulcer development. It is believed to be linked to creating stress on the horses which increases cortisol levels.

As horses run, abdominal and gastric pressure increases, pushing stomach acid up from the lower (glandular) portion of the stomach to the upper (squamous) portion. [8] This upper section of the stomach is much more sensitive to stomach acids and has less protective mucous, allowing for ulcer sores to begin to form (remember it can take as little as 24 hours for an ulcer to form). This is reflected in the increase of ulcer diagnoses in Thoroughbreds from 37% to 80-100% after 3 months of training. [9]

So What Does This All Mean?

So what we can gather from all this data is that standard management practices for performance horses (most notably racehorses) are the root cause of frequent ulcer formation. Limited grazing time, infrequent meals, high stress levels, long-term use of NSAIDs, and intense exercise all contribute to the prevalence of ulcers in performance horses across the board. Add in the genetics of a naturally high-strung breed, and you’ve got the perfect storm of ulceration. 

3 Ways to Prevent Ulcers in Horses

Now that we know what environmental factors can contribute to the development of ulcers in the equine stomach, what can we do as horse owners to help our 4-legged partners avoid this painful scenario? Basically, change every common practice in the performance horse world….no biggie right? It can seem daunting, but let’s break it down into steps. (Also, we’re not trying to change entire industries right now! Just focus on your practices and your horses.)

1. Focus on Gut Health

The first step to avoiding ulcers altogether is to focus on your horse’s gut health. We always say “A happy gut = a happy horse” and this goes beyond avoiding ulcers. Gut health is the foundation of all components of a horse’s health: mental, hoof, coat, and joint. If the gut is sick and inflamed all of these things will also suffer. Your horse’s disposition and performance will also decline because they can’t perform their best if they don’t feel their best. Are YOU happy and patient and ready to work out when you’ve got the stomach flu? Most likely not. Gut health starts with nutrition: make sure your horse has high-fiber, nutritious forage and not too much carbohydrate-rich grain. That’s Square One.

Square Two is to consider starting your horse on Foundation Daily Detox and NuTrack Digestive Support. Together, these two Animal Element supplements will clear your horse’s system daily of any toxic buildup that is making their GI tract sluggish, and allow for maximum nutrient absorption. This will not only be a huge step in the prevention of ulcers, but will also improve their joint health, topline, and condition.  

For examples of how FDD & NuTrack can save a horse, read these blogs Little Horse, Big Heart- Goldie’s Story, and 2 Powerful AE Supplements that Turned a Skinny, Cranky Mare Around.

If your horse is naturally nervous, or facing a potentially stressful situation, we suggest using In The Zone calming paste in addition to consistent use of FDD and NuTrack. This all-natural paste (that is safe for horses of all ages) coats the stomach, reducing the nervous “butterfly” feeling, and protecting it from excess acid that may be present during stressful events. ITZ does not affect your horse’s energy or adrenaline, it merely helps calm them from the inside out. (Read more about it here.)

2. Reassess Feeding

In a perfect world, all horses would have pasture access 24/7, 365. We don’t live in a perfect world, however, and plenty of horses spend most of their time in stalls or small, over-grazed paddocks. If your horse’s living situation is less than ideal don’t stress! There are still things you can do to make sure your horse is getting what they need.

  • Offer forage sources all day long by either a slow-feeder hay net or grazing. A 1,000-pound horse should get 15 pounds of forage a day. Eating dry forage requires more chewing, which produces more saliva. This saliva, as we mentioned before, acts as a buffer to the acids in the stomach.[10] 
  • Monitor your horse’s sugar AND starch intake. A 1,000-pound horse should consume no more than 900 total grams of sugars and starches combined. This includes what’s in their feed and in their hay. [11] 
  • Check your feed and supplements for fillers. These ingredients add very little nutritional value to your horse’s diet but are included to either add bulk to the feed/supplement or enhance flavor/texture/appearance. Much like they fill the container, these filler ingredients also fill your horse’s stomach because they are hard to digest. This prevents the horse from eating more of the nutritious foods they actually need. Mark Kaylor, head of sales at Animal Element says, “Horse people bought into these [expensive, multiple ingredient] feed programs, then wonder why their horses have health issues and need omeprazole constantly. The solution is to get your horses back on a simple, easy-to-digest diet with fewer ingredients, higher fiber, and just enough fat to keep them in good flesh. Read the ingredients in your feed and figure out a prevention, instead of trying to find the cures.”

Obviously, this is just a guideline and all horses have different nutritional needs. This is not meant to be veterinarian advice, please consult with an equine vet if you have questions or concerns about your feed program.

3. Avoid Chronic Medication Use 

Non-steroidal anti-inflammation drugs have a time and a place, and we are not suggesting that you stop the use of them altogether! The problem occurs when NSAIDs are used long-term, or over prescribed. If your horse has chronic inflammation, consider addressing the ROOT CAUSE of the inflammation, not just the symptoms. (This is where FDD & NuTrack can help tremendously.) This might require that you do your own in-depth research to learn about alternative therapies or herbal remedies that can bring your horse relief without damaging the lining of their stomach. 

The use of omeprazole for the treatment of equine ulcers is the only FDA-approved ulcer medication specifically for horses and has, for years, been considered the  “gold standard” of treating equine gastric ulcers. It works quickly to reduce the presence and symptoms of ulcers, but once treatment is stopped, ulcers rapidly reappear. This leads to the omeprazole “roller coaster” of 1 month on/1 month off the medication.  Gastric acids can become more acidic after the use of PPIs (proton pump inhibitors) like omeprazole, hence the frequent recurrence of ulcers. Besides a quick backslide of ulcer presence and the sheer cost of constant pharmaceutical treatment, there are concerning side effects of long-term use of omeprazole: like interactions with NSAIDs, problems with the hindgut, and negative effects on bone density. [12]

A Holistic Approach to Preventing Ulcers in Horses

The simplest way to avoid your horse getting ulcers is to…let them be a horse. Give free access to forage 24/7, whether it’s high-quality hay in a net or grazing in a pasture. Reduce their stress levels by giving them time to relax, recover, and play with their equine companions. Feed all-natural supplements without fillers like Animal Element to promote good gut health, and try to reduce the use of PPIs and NSAIDs. 

Obviously, in the equine performance world, stressful situations and hard work can’t be avoided. When you know these experiences are coming, prepare your horse by giving them a small meal and a dose of ITZ paste. A calm stomach coated with ITZ and filled with forage is less likely to develop an ulcer than a stressed out, empty stomach. Remember that proper nutrition and a healthy gut are the best defenses against ulcers that you can give your horse.

Sharing is Caring

We know, that as a caring horse owner, no one wants their horses to experience ulcers once, let alone have chronic ulcer reoccurrence. Our hope is that you can use this article to help you understand ulcers and prevent them in your horses. Feel free to share this with any of your horse owner friends and reach out if you have any questions about ulcers and the cool testimonials we have heard. 

Content is intended for informational purposes only and not as veterinarian advice. Please work with a veterinarian professional if you have questions or concerns about your horse’s health or diet. Proudly written for Animal Element by the team at FaithHanan.com

Resources:

  1. Smarsh, Danielle. “Using Nutrition to Manage and Prevent Stomach Ulcers in Horses.” PennState University Extension, 17 Jan 2022. https://extension.psu.edu/using-nutrition-to-manage-and-prevent-stomach-ulcers-in-horses
  2. Smarsh, Danielle. “Using Nutrition to Manage and Prevent Stomach Ulcers in Horses.” PennState University Extension, 17 Jan 2022. https://extension.psu.edu/using-nutrition-to-manage-and-prevent-stomach-ulcers-in-horses
  3. DePaolo, Mark. “Equine Ulcers EGUS.” DePaolo Equine Concepts, 2012. https://hl.depaoloequineconcepts.com/?q=node/5
  4. Boneff, Rachel. “Gastric Ulcers in Performance Horses.” Today’s Veterinary Nurse, 30 Aug 2018. https://todaysveterinarynurse.com/gastroenterology/gastric-ulcers-in-performance-horses/
  5. Boneff, Rachel. “Gastric Ulcers in Performance Horses.” Today’s Veterinary Nurse, 30 Aug 2018. https://todaysveterinarynurse.com/gastroenterology/gastric-ulcers-in-performance-horses/
  6. Boneff, Rachel. “Gastric Ulcers in Performance Horses.” Today’s Veterinary Nurse, 30 Aug 2018. https://todaysveterinarynurse.com/gastroenterology/gastric-ulcers-in-performance-horses/
  7. Vokes, Jessica. “Equine Gastric Ulcer Syndrome: An Update on Current Knowledge.” Animals Journal, 13 April 2023. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10093336/
  8. Van den Boom, Robin. “Equine Gastric Ulcer Syndrome in Adult Horses.” The Veterinary Journal, May-June 2022. https://www.sciencedirect.com/science/article/pii/S1090023322000454
  9. Boneff, Rachel. “Gastric Ulcers in Performance Horses.” Today’s Veterinary Nurse, 30 Aug 2018. https://todaysveterinarynurse.com/gastroenterology/gastric-ulcers-in-performance-horses/
  10. Smarsh, Danielle. “Using Nutrition to Manage and Prevent Stomach Ulcers in Horses.” PennState University Extension, 17 Jan 2022. https://extension.psu.edu/using-nutrition-to-manage-and-prevent-stomach-ulcers-in-horses
  11. Smarsh, Danielle. “Using Nutrition to Manage and Prevent Stomach Ulcers in Horses.” PennState University Extension, 17 Jan 2022. https://extension.psu.edu/using-nutrition-to-manage-and-prevent-stomach-ulcers-in-horses

Oke, Stacy. “Here’s What To Keep In Mind When Giving Your Horse Omeprazole For Gastric Ulcers.” The Paulick Report, 6 April 2021. https://paulickreport.com/horse-care-category/heres-what-to-keep-in-mind-when-giving-your-horse-omeprazole-for-gastric-ulcers

Published in Horse Care