Study of the urethral pressure profile and perineal floor electromyogram in 12 dogs subjected to colonic resection, abdominal vascular stripping and pudendal nerve transection suggests that specific defects in urethral continence function may follow pelvic and retroperitoneal surgical dissection. These alterations, attributable to damage of the pudendal nerves and the sympathetic fibers in the posterior peritoneum, must be accurately evaluated before treatment of postoperative urodynamic problems. [Results were related to human treatment after pelvic and retroperitoneal surgery.].