Background: Phenylbutazone is commonly prescribed for treatment of various painful or inflammatory disorders in horses, but is associated with gastrointestinal (GI) adverse effects. Anecdotally, many practitioners prescribe omeprazole concurrently with phenylbutazone to reduce development of equine gastric ulcer syndrome (EGUS), but the efficacy and safety of this practice remains unknown.
Objectives: To evaluate the effect of omeprazole on phenylbutazone-induced equine glandular gastric disease (EGGD) and equine squamous gastric disease (ESGD).