The clinical signs and changes in blood and rumen fluid, and the results of therapy are described in 35 cows suffering from bleeding abomasal ulcer. The most important pathological findings were moderate to severe anaemia with pale mucous membranes and tachycardia, dark coloured to black faeces, a disturbed general condition and anorexia. Two of the cows were slaughtered immediately. The others were treated by the transfusion of several litres of blood and the intravenous administration of a solution containing sodium chloride and glucose and other drugs such as calcium solution, vitamin K, vitamin C and metoclopramide. Two animals died in spite of the treatment and three had to be slaughtered because of the deterioration in their condition. The other 28 cows recovered within a few days and their general condition, appetite and defecation returned to normal.