Equine Gastric Ulcer Treatment

***DISCLAIMER*** At no time should you take any advice on this page without first discussing this with your veterinarian treating your horse. The advice on here regarding Equine Gastric Ulcer Treatment is not meant to replace the advice from your veterinarian.

The advice given on this page is mainly aimed at the UK market, but will be similar in many other countries as well, depending on your licensing laws and your own personal veterinarian’s advice.

How do I know my horse has gastric ulcers?

The only way to say for certain if your horse has ulcers is to do a gastroscopy. Only once your veterinarian has scoped your horse will they be able to tell you if your horse has stomach ulcers. In case you missed it, here are our Top 13 signs your horse has gastric ulcers.

So how do you treat equine ulcers?

The only licensed product to be used in the UK and the USA are oral omeprazoles. At the time of writing this page, in the UK you have your two oral pastes, GastroGard and Peptizole. In price checking numerous vets, we have found that on average, Peptizole is the cheaper omeprazole option, and also treats a larger horse, with one tube treating up to 700kg. Following your veterinarian’s advice, you should dose according to the weight of the horse. Best practice is to treat your horse with the required dose in the morning on an empty stomach.

What drugs can also be used to treat equine gastric ulcers?

Depending on the type of ulcers present, your veterinarian has various options to treat with.

  1. Veterinarians have to follow a strict prescribing route, called the “Cascade” in the UK. If they don’t, they are breaking the law. This could have severe implications as well, as pet insurance companies have often not paid out on claims if discovered the proper medication was not used. This means they have to use the oral paste first for a minimum of 28 days, and then re-scope. If ulcers are still present, then they can think of other options.
  2. The optimum medication to use is an oral omeprazole, at 4mg/kg dosage, for 28 days. Sometimes some horses need an additional 2-4 weeks treatment to clear up all the ulcers. Some horses don’t respond as well as they should.

Oral Omeprazole

This is very effective for the treatment of ESGD and it has been described for the treatment of EGGD. It is the only licensed veterinary medicine for the treatment of gastric ulceration.

However, oral omeprazole sometimes has a limited effect on pH in the pyloric antrum and rates of healing of EGGD lesions with oral omeprazole monotherapy (4 mg/kg once a day) are poor, ranging from 9–32% (Sykes et al, 2014b,c; Sykes, 2015b). Higher doses (8 mg/kg once a day) or increased frequency (4 mg/kg twice a day) of dosing to increase acid suppression do not appear to improve rates of healing (Hepburn, unpublished data; Sykes unpublished data). Given consistent reports of poor acid suppression in the pyloric antrum and low rates of EGGD healing, the use of oral omeprazole as a monotherapy is not appropriate for the management of EGGD. Efficacy may be increased if it is used in combination with sucralfate.

Omeprazole (oral) and sucralfate combination

Hepburn reported 80% improvement and 63% healing (grade ≤1)b of EGGD lesions (grades ≥2) in 204 sport and leisure horses treated with both omeprazole (4 mg/kg once a day) and sucralfate (12 mg/kg twice a day) (Hepburn, 2014). Improvement in pyloric lesions, which are seen most commonly in practice, was slightly lower at 67.5%. In another report, with much smaller numbers, these rates of healing (grade 0) were not replicated and only 22% of cases healed with sucralfate and omeprazole (Varley et al, 2016). The discordance may be explained by differences in the definition of healing with Hepburn considering grade 1 as healed to account for the chronic mucosal changes which can be apparent, and Varley et al (2016) aiming for complete resolution of the lesions. Sucralfate does not hold a veterinary licence and is therefore used following the prescribing cascade.

Proton pump inhibitors (PPIs) are prodrugs and require proton pumps to be activated in order for the active drug to bind and inhibit acid production. Feeding stimulates the activation of proton pumps and, in the presence of a proton pump inhibitor, paradoxically results in reduction of acid production. However, the presence of food within the stomach inhibits the absorption of PPIs so it is essential that feeding patterns are modified to maximise bioavailability. Horses should have feed removed at least 8 hours prior to the administration of oral omeprazole and food should not be provided for at least 30 minutes, and ideally 60–90 minutes after treatment. Feed deprivation prior to the administration of omeprazole may seem counter intuitive; however, most horses rest overnight and would eat very little even if they had access to forage. While daytime fasting decreases pH within the stomach, overnight fasting has little effect (Husted et al, 2009). This was a main consideration when people ask for horse stomach ulcer treatment.

Recommendations — omeprazole and sucralfate:
In combination is a valid first-line treatment option for EGGD

Combination therapy should include sucralfate at 12 mg/kg PO BID and omeprazole at 4 mg/kg PO SID. Lower doses of omeprazole are unlikely to be effective for treatment or prevention

Should only be used if omeprazole can be administered after 8 hours of feed deprivation and a minimum of 30 (preferably 60–90) minutes prior to feeding

Should be administered such that sucralfate is administered at least 30 minutes after omeprazole

Is used following the prescribing cascade as sucralfate does not have a veterinary licence.

Omeprazole long-acting intramuscular injection

  1. Does not hold a veterinary licence and is used following the prescribing cascade.
  2. Reports of painful reactions.
  3. Requires further study as limited efficacy and safety data are available
  4. The only people reporting best results are being paid by the company producing this product.
  5. One IM injection weekly basis.


Misoprostol is a prostaglandin analogue and an increasingly popular treatment for EGGD. Misoprostol suppresses acid production. However, there is limited evidence of its efficacy. In a study of 40 sports horses with clinically significant EGGD, misoprostol at 5 μg/kg twice a day resulted in healing (return to normal appearance) in 73% of horses compared with only 22% healing in horses that were receiving both omeprazole and sucralfate combined treatment.

Diarrhoea has been reported in association with high doses of misoprostol but is rare at standard clinical doses and, in the authors’ experience, is mild and self limiting. Misoprostol may compromise the acid suppressive effect of proton pump inhibitors and the two treatments should not be used simultaneously. The concurrent use of misoprostol and sucralfate has not been investigated and, although there are no known contraindications to this combination, there is no evidence to recommend it currently.

Misoprostol has the potential to induce abortion in humans and potentially in the horse, although some safety data exist for its use in mares between 100–130 days of pregnancy (Jacobson et al, 2012). While it is licensed for use in humans for the treatment of gastric disease, there is no veterinary licence and mistoprostol is therefore used following the prescribing cascade. Potential benefits have to be balanced against the risks to human handlers of the medicine.

Other products

There is no evidence to support the use of the following unlicensed products for the treatment of EGGD:


Aloe vera

Pectin/lecithin complexes



Bismuth subsalicylate

Sea buckthorn



While some of these products/approaches might have merit for the prevention of disease, they are unlikely to be of benefit in treatment and as interactions with other treatments are unknown their use ought to be avoided unless further evidence becomes available. There are so many products people recommend for horse stomach ulcer treatment.

Clinical progression, monitoring and treatment of horses not responding

Rates of healing are difficult to predict. Raised, nodular, haemorrhagic and fibrinosuppurative lesions appear to take longer to heal than flat erythematous lesions. Mucosal lesions may heal within 2–4 weeks, but frequently take far longer to resolve. When there is thickening, nodule formation or metaplasia resolution is likely to take months.

The aim of treatment should be complete resolution and a mucosa that has a normal appearance. If treatment is discontinued when there are still signs that are indicative of the presence of mucosal inflammation, there is a risk that lesions will worsen and clinical signs will recur.

Regardless of the primary treatment, repeat gastroscopic examination at monthly intervals is recommended with continual assessment of the clinical response also being important. It is important that sufficient time is allowed for each treatment to take effect and frequent changes to the treatment regimen should be avoided. If there is improvement then the same treatment regimen should be continued for a further month. If there is no improvement then an alternative treatment regimen should be initiated (Figure 12).

If there is no improvement at 3 months, biopsy should be considered. Biopsies enable assessment of bacterial involvement and the elimination of uncommon causes of gastric lesions such as Habronema spp. and Drachsia spp. Both of these conditions are extremely rare. Investigation of more generalised gastrointestinal disease should also be considered, or the response to glucocorticoids could be assessed.

Once lesions have resolved treatment should be discontinued.

Further reading

What should I feed my horse with ulcers?