Gastric ulcers are commonly diagnosed in horses these days because we have a scope to actually look inside the horse’s stomach.  Dr. Al Merritt from the University of Florida says that 50-90% of horses suffer from gastric ulcers, and performance and racehorses are the most susceptible.  A horse has two stomach regions and therefore can have two different causes of ulcers in the non-glandular and the glandular portions.  The glandular portion is very acidic at a pH of 1-2 while the non-glandular portion has a neutral pH of 5-7.  Horses produce gastric acid whether they are eating or not and when eating, saliva is produced that increases the pH.  This increase is fine for horses grazing 24 hours a day but not for horses in stalls fed twice a day.  Common clinical signs are poor appetite, dullness, attitude changes, decreased performance, poor body condition, and colic pain. 

It has been shown that horses on a high concentrate ration and those kept in stalls are more susceptible to ulcers than those out grazing on pasture.  Those eating a diet with less hay and more grain are more likely to develop ulcers so feeding more hay and more turnout is a good idea.  Using slow feeders that require horses to eat smaller amounts frequently will decrease the chance of ulcers.  Although there are numerous supplements available over the counter to prevent and treat stomach ulcers, proof of effectiveness is not required to market them since the products are classified as a supplement rather than drugs.  The products Gastrogard and Ulcergard are the only products that are FDA approved and proven to treat and prevent gastric ulcers.  Before using a supplement to treat or prevent ulcers, Dr. Merritt recommends looking for scientific data and not testimonials from horse owners.