The domestication of modern performance horses has resulted in stressors and nutritional changes that are not compatible with a horse's digestive system.

In addition, the anatomy of a horse's stomach was not designed for extended, high intensity exercise. It's for this reason you might see an increase in ulcer symptoms as your horse is brought back into work.

Understanding a horse's stomach

Horses have evolved to ‘trickle feed’ which means their stomach should only have a small amount of food passing through at any one time.

A mucousy, protective layer called the Glandular Mucosa provides protection from stomach acid on the lower section of the horse's stomach. 

When a horse participates in high intensity exercise, their stomach contracts and the acid splashes up onto the non-protected area of the stomach. This is what's known as gastric splashing.

Interestingly, gastric ulcers occur more frequently in performance horses than pleasure horses. A study of racehorses in Australia found that the incidence of ulcers increased 1.7 times for every week the horse had been in training.

Ulcers In Horses & Treating the Performance Horse

A simplistic solution would be to feed a back-to-basics diet of 100% fibrous forage and avoid high intensity exercise. While this is viable for some pleasure horses, this approach simply wont work for performance horses.

A more realistic solution is to modify your training & feeding regime and treat with medication when necessary.

Management of performance horses with ulcers

  • Always offer free choice hay or roughage. This is the key to 'trickle feeding' and will stop excess acid building up in your horse's stomach.
  • Re-evaluate your horse's intake of grain and concentrates. High grain diets produce volatile fatty acids which can contribute to the formation of ulcers. Use a nutrition tool like Feed XL  to create an accurate, balanced feeding program.
  • Spread hard feeds out over the course of the day. Instead of feeding one hard feed - try and spread this into 2 or 4 feeds per day.
  • Use 'slow-feeders' to increase the amount of time spent chewing and salivating when fed hay. Use muzzles for horses that need restricted pasture access instead of locking them up for long periods of time.

Medications for horses with ulcers

Modern performance horses often have requirements that cannot be met with management alone. With high intensity exercise training & high energy feed requirements there's usually a genuine need for medication.

The most common ulcer medications are proton pump inhibitors, protective treatments and antacids.

  • Proton pump inhibitors (PPIs) like Omeprazole are very popular with horse owners. These are effective because they completely stop the secretion of gastric acid.
  • Protective medications like Sucralfate. These work by forming a protective layer over the site of the ulcers. While sucralfate wont stop the formation of new ulcers, it's an effective way to heal existing ones.
  • Antacids. Commonly used by humans to buffer and neutralise acids, antacids are not a practical solution for horses. This is because horses need and extremely large dose of antacid for it to be effective.

Arguably, the most effective treatments for horses with ulcers is a combined treatment of omeprazole with sucralfate.

Training tips to minimise gastric splashing during exercise

Horses are very active animals - so how have they evolved to suffer from stomach ulcers?

Horses in the wild will exercise in short bursts. Usually this is to escape danger or for brief play time. After they've had a quick run, the horse will start grazing again quite soon after.

Conversely, a modern performance horse is often worked for an hour or more at a time.

These intense, extended exercise bouts can create 'the perfect storm' for the formation of ulcers in horses.

  • Exercise increases the production of gastric acid.
  • Saliva is a natural buffer against stomach acid and during exercise the production of saliva is halted.
  • Gastric splashing: The horse's stomach will contract and move during exercise. This causes stomach acid to splash onto the unprotected area of the horse's stomach.

Here's what you can do to lessen gastric splashing during training:

  • Never exercise your horse on an empty stomach. Always offer hay or chaff while tacking up.  This will create a buffer for the gastric splashing. It will also stimulate saliva production which helps to neutralise stomach acid.
  • Include regular walking or rest breaks during training. This gives the stomach acid a chance to settle.
  • Feed forage before and straight after training. Lucerne (or alfalfa) is the best for this because it's high calcium content helps buffer stomach acid.
  • Mix up training to include lower intensity workouts. This can include slow stretching & suppleness exercises and long, low & relaxed fitness training.
  • Treat your horse with omeprazole prior to exercise to stop the production of stomach acid.
  • Include turnout or paddock exercise into your horse's routine. Free grazing and the associated movement has a positive effect as they self regulate the time spent eating and exercising. Paddock turnout is also enormously beneficial for an anxious or young horses' mental wellbeing.

For most competitive riders, high intensity exercise is an essential factor in a horse's training program. Even though this is at odds with the horse's stomach design, there are ways you can manage this to minimise gastric splashing discomfort of ulcers in horses.

More Information

To order omeprazole from us, without a prescription and at a fraction of the price of 'big brands' visit our Shop Page. You can order generic omeprazole with our product called AbPrazole or try AbPrazole Plus which has the benefits of omeprazole combined with probiotics.


Gastric splashing is a common problem. Gastric splashing is a common problem.