The aim of this study was to offer an alternative therapy for gastric ulcers in horses as the interest in natural products is growing not only among practicioners but also horse owners. We compared the treatment of equine gastric squamous mucosa ulcers by omeprazol and by nutraceutical herbal mixture PREVUL (Dzsar Ltd., FitoCavallo, Hungary). A total of 36 horses, 18 geldings, 15 non-pregnant mares and 3 stallions were diagnosed with Equine Squamous Gastric Disease (ESGD) by gastroscopy. Horses were randomly divided into three groups. The first group was treated with 4 mg/kg omeprazole paste (Peptizole, Norbrook, United Kingdom) per os once daily on empty stomach for 28 days. The second group received 20 g of pulverized herbal mixture PREVUL twice daily in cracked oats for 28 days. The third experimental group received 2 mg/kg omeprazole per os once daily on empty stomach followed by 15 g of PREVUL mixed with cracked oats twice daily for 28 days. Ten healthy horses were used as control to evaluate the palatability and voluntary intake of PREVUL. Control gastroscopy was performed afted 30 days. The use of PREVUL alone P < 0.05 or in combination with omeprazole paste P < 0.01 appears to improve the healing of gastric ulcers in horses.