ULCERGARD® (omeprazole) Oral Paste for Prevention of Gastric Ulcers in Horses is the only product that's been approved by the FDA to prevent equine stomach ulcers. ULCERGARD® is a non-prescription preventive for Equine Gastric Ulcer Syndrome, a painful condition that can reduce your horse's performance and can even lead to death. ULCERGARD® contains specially formulated omeprazole that blocks acid production at its source – the acid pump. And one dose lasts 24 hours, making it easy to administer.