The kidneys produce urine continuously and the tiny pipelines through which the urine is transported from the kidneys
to the bladder are the ureters (one for the left kidney and one for the right kidney). The bladder stores the urine until it
can be voluntarily unloaded.
Ectopic ureters are a congenital error in the development of the ureters. Instead of connecting to the bladder, the
ureters connect directly to the urethra. The ureters are then bringing urine to an area that is unable to store urine and
leaking ensues. One or both ureters can be affected.
Ectopic ureters are commonly diagnosed in puppies and mostly female dogs (female to male ratio: 20:1). Often
clinical signs include urine leaking/dribbling almost constantly or intermittently, discolored fur around the vulva.
Licking of the genital area (irritation from urine) and recurrent urinary tract infections.
Several diagnostic tools can be used to diagnosed ectopic ureter in dogs.
1. Abdominal ultrasound: The normal ureter is too small to be seen with ultrasound. If the ureter is distended,
it provides some clues that one may be dealing with an ectopic ureter. In female dogs, about 50% of the
dogs will have dilated ureter(s); in male dogs up to 80%. However, a lack of ureteral dilation does not
exclude the possibility of an ectopic ureter.
2. Cystoscopy: Cystoscopy is the diagnostic method of choice for the diagnosis of ectopic ureter in females
dogs (less so in male). Cystoscopy employs a tiny camera on the end of a probe which can be used inside
the urethra, vagina, or bladder to locate the ureteral openings. An advantage of cystoscopy is that laser
ablation (see below) can often be performed during the same anesthesia thus confirming and correcting the
problem all in one procedure.
3. CT scan: CT scanning is an excellent diagnostic method for the diagnosis of ectopic ureters especially in
male dogs. It is highly accurate and reveals the exact location of the ureter attachment. This form of imaging
also requires general anesthesia.
Several treatments are available for the correction of ectopic ureter(s).
1. Cystoscopy-assisted laser ablation: Cystoscopy-assisted laser ablation is a less invasive approach with less
incidence of post-operative incontinence when compared to surgery. Laser ablation is best used for
“intramural” ectopic ureters (most common type). These are ureters that start to enter the bladder where
they are supposed to but do not actually penetrate all the way in. Instead, they continue inside the bladder
wall and open up in the urethra. The laser will be used to cut/ablate the ectopic ureter (s) back into the
bladder. Most patients are able to leave the hospital within 12-24 hours after the procedure. Males typically
become urinary continent (80%) but some 40% of females ultimately require additional treatment to remain
2. Surgery: Surgery is recommended in cases where the ectopic ureter is considered “extramural” i.e. directly
attach to the urethra (i.e. no tunneling). Extramural ectopic ureters are rare (1%) and their path is often
determined at the time of the cystoscopy or CT scan.