Delayed urethral obstruction after uterine torsion in a pregnant dog.

A 4 yr old pregnant female shih tzu was presented with abdominal discomfort and bloody vulvar discharge. The nongravid uterine horn was reflected caudally over the trigone, obstructing urine outflow. A cesarian section and ovariohysterectomy were performed. Postoperatively, the hematuria and pollakiuria resolved. Seventeen days later, the pelvic urethra was completely obstructed by a soft tissue mass that was identified by rectal palpation, blocked catheterization attempts, contrast radiography, ultrasonography, and surgery. Management included temporary cystostomy tube and definitive prepubic urethrostomy. Histologic diagnosis was severe, multifocal, necrosuppurative urethritis with fibroplasia, fibrosis, and cellulitis, apparently secondary to ischemia. Delayed urethral obstruction is a potential complication of canine uterine torsion.