The disorder can occur in male and female dogs of any age or breed. The most striking feature of urethral sphincter incompetence, however, is that the overwhelming majority of cases are spayed bitches. The onset of incontinence can take place immediately after surgery or many years later. In most cases, incontinence is observed about three years after spaying. Obviously, the underlying mechanism of incontinence in these dogs must be related to ovariohysterectomy.
Some veterinary urologists believe the culprit is low post-surgical estrogen concentrations.
This is supported by the finding that many affected bitches respond to estrogen therapy. However, the theory doesn't explain why some bitches become incontinent after spaying and others don't. Other possible causes could be related to damage of the urethra associated with uterine stump inflammation after surgery. Anatomical factors such as urethral length and bladder position could also be impl icated. Regardless of the cause of spay incontinence, it should not be viewed as a reason not to spay.