Surgical management of a ureteral defect with ureterorrhaphy and of ureteritis with ureteroneocystostomy in a foal.

A 2-day-old male foal developed uroperitoneum. Initial exploration of the abdomen via ventral midline celiotomy failed to localize the source of uroperitoneum. Bilateral nephropyelocentesis and antegrade urography were performed, and a defect in the right ureter and stenosis of the left ureter were identified. With the foal in dorsal recumbency in the Trendelenburg position, ureterorrhaphy was performed on the right ureter. After ureterorrhaphy, a ureteral catheter was maintained as a stent. The stenotic left ureter was transected, and ureteroneocystostomy was performed using a drop-in mucosal apposition technique. The ureteral catheter was removed 26 days after surgery. Histopathologic findings suggested that ureteritis of unknown origin was a possible initiating factor for stenosis of the left ureter. The drop-in technique for ureteroneocystostomy may be used successfully for ureteral transposition in horses. Ureterorrhaphy combined with the use of a ureteral stent may be used to repair ureteral defects in foals.