Omeprazole Drugs for Stomach Ulcers in Horses: Some Don't Have Enough Omeprazole

February 1, 2005 (published) | June 1, 2015 (revised)

Stomach ulcers in horses are correctly called gastric ulcers. They are common in race horses and other performance horses. Only two products that treat and prevent these ulcers are approved the FDA; they are Ulcergard and Gastrogard. However, there are many other products marketed for treatment and prevention of gastric ulcers and the FDA is concerned about the safety and efficacy of these unapproved products. Because of this, the FDA recently issued nine warning letters to companies manufacturing drugs containing the active ingredient omeprazole.

Testing by the FDA revealed that some of these unapproved products contained as little as 36% of the omeprazole claimed on the label to as much as 135% of the amount claimed. Because of these variances, the FDA wants horse owners to know they are concerned about the use of these unapproved products, including those containing omeprazole. Safety is one concern with these unapproved products as you really do not know how much of an ingredient is really in the product. Also, the efficacy of the unapproved product is questionable, especially with products containing omeprazole. Many studies have shown that most of the unapproved omeprazole products that are being used in horses are ineffective as they are destroyed by stomach acid before being absorbed. It is important to check with your veterinarian concerning the use of any product used in your horse; although FDA approved products may be more expensive, in this case you do really get what you pay for.

VIN News Service commentaries are opinion pieces presenting insights, personal experiences and/or perspectives on topical issues by members of the veterinary community. To submit a commentary for consideration, email

Information and opinions expressed in letters to the editor are those of the author and are independent of the VIN News Service. Letters may be edited for style. We do not verify their content for accuracy.