Preventing Gastric Ulcers in Horses

Once upon a time, I kept my barrel racing mare, P.K., in a dry lot for a good portion of the day to ‘help’ her lose weight.  I didn’t know it at the time, but not only are starvation diets  counterproductive for weight loss, but they can also lead to gastric ulcers.   I cringe at the thought now.  Oh, the things we do to our horses. . .

If you don’t know what gastric ulcers are, they’re essentially holes in the stomach lining (mucosa) that have been worn away by acid.   It’s been estimated that 90% of race horses, 70% of endurance horses, and 60% of show horses are affected by this condition.  This is a big problem, obviously, and one that can usually be prevented.

Foals are also susceptible to gastric ulcers because they secrete gastric acid (which is more acidic than that of adult horses) as early as two days old.   But for the purposes of this post, I’ll focus on adult horses.


Causes of Gastric Ulcers

There are two main factors associated with the formation of gastric ulcers in (adult) horses: feeding practices and stress.   The good news is that both of these can be managed more appropriately to greatly reduce the horse’s chances of developing this painful condition.


stalled horse 2


Acids are continually produced by the stomach, but food and saliva (which is formed primarily by chewing forage) act as a buffer against these acids.  When the horse has nothing to eat, saliva production decreases and there is nothing to protect the sensitive lining of the stomach from the acid.

Anatomically, the stomach is quite small compared to the rest of the digestive system.  Food enters and then exits in about a fifteen minute time span.  This works well when the horse is consuming small amounts of forage on a near-continual basis as he was designed to do, but as most of us know, many horses don’t get to do this.  (see this post for more info. on the horse’s digestive process. . .)

Grains and high-carbohydrate feeds are another contributor to ulcers as they increase volatile fatty acid production in the stomach.  Grain is not a natural part of the horse’s diet, especially in large amounts.  Incidentally, studies have been conducted and have shown that high quality forage can be substituted for grain in many circumstances.  (see  my articles on forage-only diets for horses in training and performance horses published in The Horse.)

Exercise, especially if it’s intense,  also increases stomach acid production.  The acid is then ‘sloshed’ around, continually bathing the stomach in acid.  In addition, stressors, such as hauling, competition, or stall confinement can also increase acid production.


young race horse


I should also mention that NSAIDs like bute, flunixin meglumine, or ketoprofen,  decrease the production of the stomach’s protective mucus layer, making it more susceptible to ulcers as well.  These should never be given long-term!

It should be easy to see now why so many performance horses are affected by gastric ulcers. . . But let’s move on to how we can help prevent this condition.


Preventing Gastric Ulcers in Horses

The most important key to preventing gastric ulcers is managing and feeding the horse in alignment with his natural tendencies.  We tend to see our domestic horses as almost an entirely different species than the feral horses that seem to be naturally immune to problems like ulcers.  But the truth is that they are one in the same.  It’s only our feeding and management practices that are to blame here.


horses grazing


Since an empty stomach sets the horse up for ulcer formation, ensuring that your horse has something to eat day and night is key for preventing (and also treating) ulcers.  If the horse cannot be put on pasture, hay should be fed on a frequent basis.  Implementing a slow feeding system can help tremendously.

Also, adding some alfalfa into your horse’s diet has been found to be helpful.  According to this article from The Horse, “researchers at University of Tennessee, (University of) Kentucky, and Texas A&M discovered that alfalfa hay was more efficient in buffering against stomach ulcers than grass hay, due to the higher level of calcium (and protein) in alfalfa. The extra protein and calcium can both act as potential buffers for stomach acid.”

(However, I would like to point out that feeding a diet of primarily alfalfa isn’t recommended as it can create a major mineral imbalance and increase the risk of enteroliths–see this post for more. . .)

We should eliminate stress however we can for the horse.  Allowing him to live with other horses, giving ample turnout time, and minimizing intense exercise are all crucial in preventing ulcers.

So to review, here are some tips for preventing gastric ulcers in horses:

  • Keep horses on pasture, feed hay frequently or free-choice, or use a slow-feeder;
  • Reduce or eliminate grains and/or high carbohydrate feeds from diet;
  • Limit or avoid use (especially long-term) of NSAIDs (firocoxib and/or bute alternatives can be used instead);
  • Feed hay or allow grazing before exercising your horse;
  • Limit stressful situations such as intense training and transport; and
  • Allow horses to live with a pasture mate or herd to minimize stress at home.


Stay tuned for another post coming soon on natural treatments for gastric ulcers in horses!





Keeping Horses Healthy: Update on Gastric Ulcers

Diagnosing and Treating Gastric Ulcers in Horses

Reducing the Risk of Gastric Ulcers in Horses

Preventing Equine Gastric Ulcers

Part 1: Natural Ulcer Relief for Horses

Equine Ulcers: You Really Need to Know More!



Hi! My name is Casie Bazay. I'm a mom, a freelance writer, and a certified equine acupressure practitioner.

You may also like...

3 Responses

  1. Sandi McCarthy says:

    It seems in one article concerning feet you say to only feed grass hay, in this article you say to feed alfalfa along with grass. I am on the mind set of a little of both for the reason stated in this article concerning balance of nutrients. I also turn out to pasture, and feed three-four times daily.
    I do agree with to many people feed way to much sweet feed. I only use whole oats, and only to administer vitamins. I think it is a good thing you are trying to do with the information, it just seems that with all information, it depends on who you talk to and you get many different opinions. I have a friend who will “only feed grass hay cause alfalfa is to rich” Yet they give there horses all kinds of sweet feed along with the hay.

    • then5925 says:

      Hi Sandi,

      I’m just stating what some researchers have said about alfalfa–that feeding some will help with ulcers. I don’t think adding a little alfalfa to most horses diet will hurt. It’s diets composed of mostly alfalfa that are a problem. It throws the calcium to phosphorus ratio off (unless something like bran is fed with it). It’s also a risk for enteroliths. I feed my horses about a cup of soaked alfalfa pellets a day though for added protein and to mix their minerals in (this along with timothy pellets). I don’t think sweet feed is a good idea in any circumstance though!

    • then5925 says:

      Also wanted to add I think having access to low sugar/ starch forage (whether it be pasture or hay) all the time is probably most important in preventing ulcers. If the stomach never gets completely empty, ulcers most likely won’t have a chance to develop!

  2. michelle blake says:

    When my vet first suspected that my horse had gastrix ulcers he suggested UlcerGuard but that is very expensive. My trainer mentioned that Abler sells omeprazole for horses for 1/10 the price. Later my vet suggested trying Gastrix. It is a herbal mixture with aloe vera, slippery elm, licorice, honey etc etc . My horses responded really well, love the taste and I have not had issues with ulcers since. 🙂

Leave a Reply

Your email address will not be published. Required fields are marked *