Best treatment for ulcers in horses

In this article we will explore gastric ulcers in horses, also called Equine Gastric Ulcer Syndrome (EGUS). We will look at not just the best treatment for ulcers in horses, but we will explain symptoms, causes and future management if your horse has been diagnosed with gastric ulcers, because treatment is really just one phase of the total management of a horse with ulcers.

Do you suspect your horse has ulcers? Have you heard people talking about gastric ulcers in horses but not really understood what they were saying? Read on and let’s explore this topic.

Does my horse have ulcers?

I expect if you have found this page then you suspect your horse does in fact have ulcers. Unfortunately gastric ulcers are far Gastric ulcers in horsesmore common than many horse owners realise.

Statistics indicate that between 80% – 90% of racehorses, that includes thoroughbreds and standardbreds have ulcers.

Further research indicates that many competition horses, endurance (70%) and show horses (60%) also have ulcers to some degree.

There are many reasons horses are susceptible to ulcers.

Why and how do horses get ulcers?

It is necessary to understand some basic anatomy about a horses stomach to understand why and how ulcers occur.

The horse has a small single stomach, and are classed as non-ruminants. In comparison to ruminants, mammals that acquire nutrients from plant-based food by fermenting it in a specialized stomach prior to digestion eg. cows, sheep.

The horse’s stomach is a simple single chamber where the bulk of the digestion takes place. Due to the size horses need to graze and eat small, frequent meals throughout the day. This is why grazing is preferable to large meals fed at either end of the day.

Grazing and gastric ulcers in horsesAs your horse is designed to graze stomach acid is produced 24/7 to enable a steady flow of acid to aid in this digestion. Regardless of whether there is food present in the stomach or not, up to 35 litres of acid are produced every day.

During grazing this acid is buffered by additional saliva caused by chewing and the actual presence of fibre/roughage in the stomach.

So you can see that by feeding two large meals either end of the day as most of us do, with stabled or yarded horses, we are interfering with the natural digestive process.

Research has shown that exercise further increases gastric acid production, combined with exercise on an empty stomach and the acid will splash onto the exposed portion of the stomach to the increased pH levels of acid. Blood flow to the gastrointestinal tract is also lessened during exercise further increasing the risk of ulcers.

Other physical environments and stressors can also increase the risk of your horse developing gastric ulcers. These include stable confinement, transport and the use of NSAIDs (non-steroidal anti-inflammatory drugs eg. Bute, Flunixin).

Many of the NSAIDs will reduce the amount of mucus produced within the stomach, this mucus further protects the stomach wall and without it the risk of ulcers is increased.


Horses are very stoic creatures and many horses with ulcers will not show any outward signs of discomfort, thus often making a correct diagnosis from symptoms difficult. Some more subtle indications can include:Ulcers in Horses

  • Poor Appetite
  • Picky, slow or fussy eating
  • Dull or poor coat condition
  • Loss of weight resulting in poor body condition
  • Girthy or reluctant to move forward under saddle
  • Attitude changes including increased biting
  • Loose manure
  • Low grade colic symptoms

Ulcers are graded on a Level of 0 – 3 dependent on the severity and depth of the ulcers and how they have affected the stomach lining.

  • Grade 0 – inflamed but epithelium is still intact
  • Grade 1 – superficial grazing of the mucosal surface
  • Grade 2 – erosion of the mucosal surface in one area only (single)
  • Grade 3 – multiple and severe damage to the mucosal surface, often with active haemorrhaging ulcers.

Horses with High Grade ulcers (Grade 3) may show more acute signs including abdominal pain including advanced colic symptoms (if you are not sure about colic in horses check out our article here), horses may walk away from food once they start eating as eating inflames the ulcers and cause discomfort, horses may also grind their teeth when higher grade ulcers are present.


Veterinarian Gastric Ulcers in HorseThe only conclusive way to diagnose gastric ulcers is to have your horse tubed. Called an Esophagogastroscopy, it is simply a scope which is passed down the horses esophagus (similar to tubing a horse to drench).

The scope is passed into the stomach to be able to view (scope) the stomach lining. Usually a light sedation is all that is required, although this is a specialist procedure with specialist equipment so not all vets can perform this procedure.

If you live remote like I do, your vet may recommend a blood test which can provide indicators to the likelihood of your horse having ulcers.

We did this with my gelding Jonny and started him on a course of oral treatment. His response and the change in him both physically and mentally confirmed to me that he did indeed have ulcers as the medication made the world of difference.

What treatment did we use?


Many all natural people and companies will promote their products to cure gastric ulcers. Personally if your horse has been diagnosed with ulcers by a veterinarian then I would be going with a veterinarian prescribed treatment.

Omeprazole, is the drug of choice these days to effectively treat ulcers. This is what is known as a proton-pump inhibitor which effectively inhibits the production of gastric acid for up to 24 hours after administration. Most courses of the drug will run for 14 – 16 days and can be further repeated if you or your vet feel the ulcers have not healed adequately.

Omeprazole is swabbable, so trainers must follow veterinary instructions on withholding periods if treating race horses.

This drug has been shown to be the most effective treatment, with most horses showing a marked improvement within 3 days of treatment commencing.

Ongoing Management/Treatment

Following an initial course of Omeprazole ongoing management and treatment is required for the life of the horse. Whilst the initial ulcers can be cured, horses that have had ulcers are predisposed to have them reoccur, but with careful management this can be avoided.

Now is the time to consider any herbal supplements. The following herbs have been shown to increase the mucosal properties of the stomach, and therefore help prevent re-occurance of ulcers:Gastric ulcers

  • Comfrey leaf
  • Liquorice
  • Slippery Elm
  • Marshmallow Root
  • Meadowsweet

Stable management and correct feeding is also key to preventing re-ocurrance.

  1. Always feed your horse at least 30 minutes, preferably 45 minutes, before all exercise.
  2. Lucerne hay or chaff should be fed as the small pre-exercise meal. Lucerne has been shown to mat on top of the stomach, thus helping to prevent stomach acid splash as well as the additional calcium in lucerne binding with the acid.
  3. Feeding should include ad-lib access to grazing (preferred) or ad-lib hay available 24/7.
  4. Remove all grain based feeds, replace with pelleted feeds.
  5. Feed at ground level. This is a more natural feeding position for a horse and more directly simulates grazing
  6. Avoid extended treatment with NSAIDs. Obviously if your horse requires this treatment you need to balance this up with the damage being caused to the stomach lining. Advise your vet if your horse has had ulcers before commencing any treatment with NSAIDs.
  7. Addition of 100ml of Apple Cidar Vinegar (per 500kg horse) in one meal a day may promote additional salivation and thus help to coat the stomach lining.

In Conclusion

Having a horse with gastric ulcers is not the end of the world. Following treatment and with careful management moving forward you can have a healthy happy horse. I feel far too many horses are going diagnosed and without treatment when it is such an easy fix and makes such a difference to your horse’s general well-being.

If your horse has any of the above symptoms, or if you have an inkling that ulcers may be present, talk to your vet about possible diagnosis and the best treatment for ulcers in horses.

As always if this has raised any questions please feel free to comment below. We love to hear your stories and will help out when we can.

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Horses are my passion. And while not everything in horses is black and white, and there are many choices you will need to make for your horse, I hope to explain things in a way that helps you make informed decisions, so you can provide the very best life to your horse.

  • Madeleine says:

    Great article! My three horses used to have ulcers too, I self diagnosed them based on the symptoms they were having… cinchy, very loose manure to the point of diahrea, poor coat. At that time,I was feeding them twice per day so there were periods inbetween where their stomachs would have been empty. The horse with the worst conditions I purchased from a summer camp, another was a rescue and always anxious, and the third was absolutely terrified (and angry) after being sold by his long time owners, to me. I gave them all slippery elm bark, marshmallow root, aloe vera mixed into a pelleted horse ration. I also began giving them three meals of hay per day. All of the ulcer conditions disappeared with no Vet intervention. The horse that was angry about being sold, I had to supplement with magnesium too, to calm his nerves. It’s become known that ulcers will go away on their own too, when horses are on 24/7 pasture with minimal stress. Since 2010, we use hay netting so the horses have hay in front of them all the time, this is crucial to preventing most ulcers. You also made a good point about grain. I have taken my horses off of ALL grain recently. It is my opinion and that of many Vets, that Grain is most likely the cause of many horse problems, especially laminitis and does not help ulcers one bit. One of my horses has been struggling with laminitis for 2 years, and recently extreme COPD. He made a 90% improvement when I took all grain (pelleted horse ration) away from him, even though I was not giving him much at all. He is one high maintenance horse! I suspect he has an allergy to corn and soy, which are both in the horse rations.

    • Heidi says:

      Hi Madelaine, yes so many horses have ulcers and unfortunately many do go undiagnosed. Sounds like you were onto it and the changes you are making are having positive effects for your horses.

      It is wonderful to see the changes once the pain subsides for these horses. My boy Jonny was a completely different horse once we had his under control.

      Good on you for listening to your horses and trying something different to help them.

  • Ben Farrell says:

    Hey there,

    I’m really glad I came across this website for this very informative read, my horse is currently suffering from an ulcer I think, I have an appointment with my vet to check but having read this I think it has already confirmed it for me, she isn’t eating as much as usual and her coat is less shiny which isn’t nice for a horse named Shiny, also her manure is very sloppy, I’ll still be attending the appointment for sure but I feel confident already what I’m dealing with now and I thank you for this article.


    • Heidi says:

      Thanks for the comment Ben and I’m glad you found the article helpful. It is amazing to me the high numbers of horses that have ulcers for one reason or another. Good on you for getting a vet out to your mare, if she does have ulcers the treatment will make such a difference.

      Be sure to speak to your vet about ongoing management once the treatment has finished, this way you can keep her happy and healthy into the future.

      Well done for being a fantastic horse owner. 

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