Ureteral duplication

From Dog

Congenital ureteral duplication is a rare ureteral disease characterized by in situ replication of one or both ureters, resulting in partial or complete urine obstruction to the affected kidney.

This condition may also be associated with renal duplication in the dog[1].

The duplicated ureter, usually occurring unilaterally, may travel from the renal hilus to the bladder but is often non-functional, ending blindly as with ureteral atresia.

Clinically affected dogs usually present with chronic cystitis, hematuria and abdominal pain[2], although some dogs may be asymptomatic and the condition may only be an incidental finding at postmortem.

Diagnosis is based on presenting clinical signs, radiographic or ultrasonographic evidence of a cystic mass associated with the bladder or kidney and excretory urography, which usually shows ureteromegaly and renal hydronephrosis.

A differential diagnosis would include other causes of hydronephrosis such as ureteroliths, nephroliths, pyelonephritis, urothelial carcinoma, ureteral stenosis, circumcaval ureter, ureteral atresia and ectopic ureter[3].

In unilateral cases, a nephrectomy and ureterectomy are usually curative, although in human patients, an end-to-side ureteroureterostomy anastomosis is usually the recomended procedure[4].


  1. O'Handley P et al (1979) Renal and ureteral duplication in a dog. J Am Vet Med Assoc '174(5):484-487
  2. Esterline ML et al (2005) Ureteral duplication in a dog. Vet Radiol Ultrasound 46(6):485-489
  3. North C et al (2010) Congenital ureteral ectopia in continent and incontinent-related Entlebucher mountain dogs: 13 cases (2006-2009). J Vet Intern Med 24(5):1055-1062
  4. Liem NT et al (2012) Single trocar retroperitoneoscopic assisted ipsilateral ureteroureterostomy for ureteral duplication. Pediatr Surg Int 28(10):1031-1034