Ectopic Ureter

An ectopic ureter is a congenital abnormality of the ureter (the tube that carries urine from the kidney to the urinary bladder) in which the ureter does not enter the bladder at the normal anatomic site. Dogs and cats are born with this condition, and it can involve one ureter or both. In some cases, the ectopic ureter travels within the bladder wall tissue for a distance and then opens in an abnormal location (intramural). In other cases, it does not tunnel within the bladder wall and instead inserts abnormally from the outset (extramural). Other congenital abnormalities affecting the kidneys and urinary tract may also be present.

Clinical signs of an ectopic ureter may appear in a young puppy or kitten, or sometimes in a young adult. Female dogs are reported to be 20 times more likely to be diagnosed with ectopic ureters, and certain breeds are affected more often, including Golden Retrievers, Labrador Retrievers, Skye Terriers, and others. Signs may include:

• continuous or intermittent urinary incontinence (leakage) or urinary “accidents”
• difficulty with housetraining
• urine leakage while lying down and/or sleeping
• dribbling urine
• recurrent urinary tract infections (UTIs)

Your veterinarian may suspect ectopic ureters based on your pet’s age, breed, and clinical history. A comprehensive evaluation is recommended to exclude other causes of the symptoms. This will typically include bloodwork—complete blood count (CBC) and a chemistry panel—along with urinalysis and urine culture. Survey radiographs (standard x-rays) may be used to screen for urinary stones or other abdominal abnormalities. Abdominal ultrasound can also be used to evaluate for stones or bladder disease, and in some cases ectopic ureters can be identified on ultrasound.

However, definitive diagnosis often requires advanced imaging. This may involve intravenous contrast dye with radiographs (Figure 1) or a computed tomography (CT) scan (Figure 2) to outline the urinary tract and determine where the ureters are inserting. Another diagnostic approach is endoscopic evaluation using vaginourethrography with cystoscopy, in which a camera is passed into the vagina, urethra, and urinary bladder to assess the distal ureteral openings. Certain types of ectopic ureters may also be treated during this same procedure (Figure 3b).

Recommended/possible tests include:

• Bloodwork: CBC, chemistry panel, urinalysis, and culture
• Contrast radiographs: x-rays after IV administration of contrast dye to highlight the kidneys and urinary tract (Figure 1)
• Ultrasound: to assess anatomic abnormalities and evaluate for abnormal urine flow
• Contrast CT: to evaluate the urinary tract (Figure 2)
• Vaginourethrography with cystoscopy: camera examination of the vagina, urethra, and urinary bladder to evaluate distal ureteral openings (Figure 3b)

Figure 1
Figure 2
Figure 3

Management depends on the ectopic ureter type. For intramural ectopic ureters, surgical options can include open bladder surgery to remove abnormal tissue. As an alternative, a minimally invasive method can be performed under video guidance using laser equipment to open the abnormal ureteral segment back into a more appropriate location.

For ectopic ureters presumed to be extramural, the typical recommended procedure involves transecting the ureter from its abnormal insertion site, creating a new opening in a more normal location, and reattaching the ureter to the urinary bladder.

Post-treatment care varies with the chosen technique. If an open abdominal approach is performed, about two weeks of activity restriction along with incision care is recommended. If a minimally invasive approach using cystoscopy is used, patients can usually return to normal activity sooner. Serial follow-up urinalyses and urine cultures are recommended.

Key postoperative risks include persistent incontinence, leakage of urine into the abdominal cavity, stricture (narrowing) at the surgical site, and urinary tract infection. If incontinence persists, additional improvement may sometimes be achieved with medications that increase urethral sphincter tone and/or placement of an adjustable artificial urethral sphincter.

Male patients with urinary incontinence due to ectopic ureters may have higher success rates after surgery—reported at 70–80%—than females. Unfortunately, even with surgery and medical management, 25–70% of female patients may continue to have persistent urinary incontinence.