Ureteral stenosis

From Dog

Ureteral stenosis is a congenital ureteral disease of dogs characterized by narrowing of the ureter.

Secondary ureteral stenosis is commonly observed with ureteroliths and following ureterectomy[1], accidental trauma to the ureter during routine ovariohysterectomy or following renal transplantation[2].

This condition may occur either unilaterally or, more commonly, bilaterally. In congenital cases, they are frequently located at the uretopelvic junction of each ureter.

Severely stenotic ureters are often found in young pups that fail to thrive following birth and die from acute renal injury within the first few weeks of birth[3].

Less severely affected dogs with partially stenotic ureters may only present with signs of chronic renal disease such as chronic hematuria and cystitis.

Blood tests are usually unremarkable in dogs with chronic stenosis unless significant hydronephrosis has occurred, in which cases, uremia may be evident in blood tests, with azotemia and hyperkalemia commonly observed.

Diagnosis may be attempted by excretory urography but in severely stenotic ureters, a retrograde ureteropyelography might be required.

A differential diagnosis would include pyelonephritis, urothelial carcinoma, ureteroliths, circumcaval ureter associated with portosystemic shunt[4], ureteral atresia, ureteral duplication[5] and ectopic ureter[6].

Unilateral cases may be treated with unilateral nephrectomy and ureterectomy. Bilateral cases are more challenging and may require ureteral stents, which is often successful, providing the cases is diagnosed early and renal hydronephrosis has not resulted in extensive nephron loss.

In severely affected dogs, euthanasia may be a viable option.

References

  1. Zhang J et al (2012) Ureteral reconstruction using autologous tubular grafts for the management of ureteral strictures and defects: an experimental study. Urol Int 88(1):60-65
  2. He B et al (2013) Classification of Ureteral Stenosis and Associated Strategy for Treatment After Kidney Transplant. Exp Clin Transplant Feb 21
  3. Pullium JK et al (2000) Congenital bilateral ureteral stenosis and hydronephrosis in a neonatal puppy. Contemp Top Lab Anim Sci 39(5):34-36
  4. Doust RT et al (2006) Circumcaval ureter associated with an intrahepatic portosystemic shunt in a dog. J Am Vet Med Assoc 228(3):389-391
  5. Esterline ML et al (2005) Ureteral duplication in a dog. Vet Radiol Ultrasound 46(6):485-489
  6. 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