GASTROGARD has been shown to heal or significantly improve ulcers in 99% of treated horses.1 The active ingredient, omeprazole, works to suppress the secretion of gastric acid and gives the ulcer time to heal. The safety of GASTROGARD paste has not been determined in pregnant or lactating mares. GASTROGARD is for use in horses and foals 4 weeks of age and older. Caution: Federal (USA) law restricts this drug to use by or on the order of a licensed veterinarian.