Bilateral ureterocystostomy to correct left ureteral atresia and right ureteral ectopia in an 8-month-old standardbred filly.

Objectives: To report the diagnosis and outcome after surgical correction of bilateral distal ureteral anomalies in a Standardbred filly.

Study Design: Clinical case report.

Animal: An 8-month-old, 310 kg Standardbred filly with left ureteral atresia and right ureteral ectopia.

Methods: The filly was admitted for evaluation of incontinence since birth and severe urine scalding of the hindquarters. Diagnosis was made by both direct (cystoscopy and vaginoscopy) and indirect (intravenous pyelography, ultrasonography, and scintigraphy) evaluation of the ureters and bladder. The filly had left ureteral atresia, hydronephrosis, and decreased left-sided renal function and right ureteral ectopia before surgery. Surgical correction was performed on the left by an end-to-side stapled anastomosis technique and on the right by a side-to-side hand-sewn anastomosis technique.

Results: Surgical correction was successful. The filly had no postoperative complications and remained continent 18 months after surgery. Left renal function improved.

Conclusion: Ureteral anomalies can be successfully repaired in larger (>300 kg) foals and some renal function may be restored after surgical correction.

Clinical Relevance: Scintigraphy should be considered in diagnosis of ureteral anomalies, assessing renal function, and determining prognosis for horses with hydronephrosis caused by ureteral ectopia and atresia.