Abstract: Although, abomasal ulceration is well studied in cattle, there is no data about the clinical and biochemical pictures of abomasal ulceration in buffaloes and native breed cattle. Objective was to describe the clinical, biochemical and pathological findings and response to medical treatment of abomasal ulceration in buffaloes and native breed cattle. Sixteen animals (buffaloes = 10, cattle = 6) were examined. They included 7 males (beef calves) and 9 females (dairy cows). Age range was 10 months to 8 years. All animals underwent a thorough clinical examination. Blood samples were taken for hematological and biochemical examinations. Animals were fed on high quality hay with no concentrates and treated with normal saline solution (5 L daily IV/5 days), oxytetracyclin (10 mg kg^-1 deep IM/7 days), Ranitidine (3 mg kg^-1 daily IM/7 days) and oral 50 g of sodium bicarbonate for 1 week. Results revealed that signs of abomasal ulceration disappeared in 9 animals (buffaloes = 5, cattle = 4, male = 7, female = 2). Response appeared after 1-2 weeks of treatment. No response to treatment was recorded in 7 animals (buffaloes = 5, cattle = 2, male = 0, female = 7) that were slaughtered and thoroughly examined at necropsy. At necropsy, abomasal ulceration was found along the greater curvature and on the most ventral part of the fundic region in 5 cases (buffaloes = 4, cattle = 1). Ulcers were non-bleeding, bleeding, perforating with localized peritonitis, perforating with diffuse peritonitis. Biochemical analysis revealed an increase in free fatty acids, segmented neutrophils, β-globulin and blood glucose.