Page 6 - Diagnosing and managing urinary incontinence in dogs

experienced transient urethral obstruction that required an indwelling urethral catheter (Bartges JW;
JVIM 2011). Longer-term outcome scores for urinary incontinence will be reported at the conclusion
of this 2-year study. It has yet to be determined whether PDMS will be marketed to veterinarians.

We recommend urethral bulking treatment over standard surgeries in most dogs. The recent

development of a urethral hydraulic occluder (artificial urethral sphincter - AUS) is a much less
invasive surgical technique that is being used at our institution and is currently offered as the first
option in most dogs with PSMI. This technique was originally described in cadaveric dogs that
showed highly increased MUCP following placement of the AUS (Adin AVJR 2004). The long-term
(26-30 months) efficacy of this occluder was demonstrated in 4 clinical female dogs with PSMI by
the same major investigator (Rose Vet Surg 2009).

Data from over 20 dogs (Adin; ACVS Forum 2011) studied by the same group suggests about a
90% success rate for major improvement in urinary continence scores lasting long time periods
following placement of the AUS; 2 dogs developed urethral obstruction months after the procedure
that required removal of the AUS. In our institution placement of the AUS is now the preferred
treatment over urethral bulking agents in most cases.

Ectopic Ureter
Ectopic ureter is the most common anatomic abnormality causing urinary incontinence in dogs; it is
very rare in cats. Patients are usually young at presentation (< 1 year of age and females are
diagnosed more often than males). Ectopic ureters are more common in certain breeds including
Siberian huskies, Labrador retrievers, Golden retrievers, Soft-Coated Wheaten terriers,
Newfoundlands, and Poodles. Related Entlebucher Mountain Dogs affected with ectopic ureter(s)
have recently described both with and without urinary incontinence (North JVIM 2010).

Bilateral involvement with ectopic ureter is detected more often than unilateral; early reports of
primarily unilateral involvement likely were affected by limitations of imaging (i.e. lack of
urethrocystoscopy). Most ectopic ureters in female dogs terminate in the urethra after tunneling from
more proximal locations (Cannizzo K.J Am Vet Med Assoc 2003).

Ectopic ureters may have their terminal opening still within the bladder, at the vesico-urethral
junction, proximal to distal urethra, and the vestibule. Extramural ectopic ureters are reported rarely.
Ectopic ureters uncommonly terminate in the vestibule. Ectopic ureters may terminate in the vagina
or uterus, but we have not encountered this presentation in our hospital. In the Entlebucher
Mountain Dog, ectopic ureter(s) within the bladder were not associated with urinary incontinence but
were occasionally associated with hydronephrosis; termination points of the ectopic ureter in the
urethra were associated with urinary incontinence and sometimes with hydronephrosis (North JVIM