The clinical findings and outcomes in five bulls with a perforation or rupture of the urachal diverticulum are described. All the bulls had a dilated round or pear-shaped abdomen, bruxism, ruminal atony, and dehidration. In all the bulls, abdominocentesis yielded a stream fluid and the serum concentrations of urea and creatinine were 220 to 280mg/dL and 65 to 82mg/dL, respectively. Peritoneal fluid concentration of urea was higher than 200mg/dL. In fours bulls, urachal diverticulums were closed next to the cranial pole of the bladders. After the surgery, the recovery was effective
cattle; urachus; cystic dilatation; uroperitoneum