Ectopic Ureter in Dogs
An ectopic (displaced) ureter is a congenital abnormality in which one or both ureters open into the urethra or vagina. Bilateral ectopia affects both ureters, and unilateral ectopia affects one ureter. Dogs affected with ectopic ureter will have the tubular shaft bypass the bladder floor (trigone) and enter through the bladder wall. Less frequently, the ureter opens into the bladder floor and continues as a trough into the urethra.
The following dog breeds may be predisposed to displaced ureter: Labrador Retriever, Golden retriever, Siberian husky, Newfoundland, Bulldog, West Highland White Terrier, Fox Terrier, and Miniature and Toy Poodles.
This condition is rare, especially in male dogs. Occasionally, a dog with this abnormality may be asymptomatic and show no apparent urination problems. However, some common symptoms to look out for include occasional or continuous incontinence, and inflammation of the vagina (vaginitis) from urine scalding the vaginal tissue.
Ectopic ureter has an unknown mode of inheritance, but there does appear to be a component of breed predisposition.
Your veterinarian will use a diagnostic technique called urethrocystoscopy, which uses an insertable tube with an attached camera. In this way, the veterinarian will be able to examine the dog's bladder internally, and visualize the opening into the urethra or vagina. Your veterinarian will also be looking to identify holes (perforations) in the structure of the urethra (urethral fenestrations), depressions, striping (or streaking), and tenting in the bladder.
When this diagnostic method is performed skillfully, a more accurate diagnosis can be made than with external imaging techniques, such as X-rays. Another technique, urethral pressure profilometry, measures surface variations to detect coexistent urethral muscle (sphincter) incompetence. There remains the possibility that a displaced ureter will confound the results of this test, however.