Incontinent Dog
Is your female dog suddenly dribbling urine in her sleep or even while she's climbing stairs? If so, she may be suffering from urinary incontinence, which commonly affects middle-aged and older spayed female dogs.

And although many owners simply assume that incontinence signifies an untreatable, age-related change, it turns out that it is often an easy problem to solve. 

Here's a look at how the condition is diagnosed — and what veterinarians will do to treat it.

What Causes Incontinence in Dogs?

There are several potential culprits behind canine urinary incontinence:

  • Bladder infections, stones, polyps or tumors
  • Overflow incontinence, which occurs when a dog is affected by a medical condition that causes her to drink excessively, such as diabetes and Cushing’s disease
  • Spinal cord disease
  • Developmental urinary tract abnormalities, including ectopic ureters and vaginal strictures
  • Weakened bladder (urethral) sphincters in spayed female dogs, also known as estrogen-responsive or spay incontinence, which is the most common cause

How Is Canine Incontinence Diagnosed?

As a first step, veterinarians will usually recommend a urinalysis and a urine culture. If the urinalysis reveals evidence of a medical disorder that may be causing your pet to over-consume water, your veterinarian will likely recommend complete bloodwork in order to make a definitive diagnosis. The urine culture is used to identify the type of bacteria growing in the urine.    

Depending on the gender and age of your dog, your veterinarian may recommend additional testing, such as abdominal X-rays or an ultrasound. The following are some common reasons why your veterinarian might order such tests:

  • Male dogs aren't typically affected by urinary incontinence, so they need to be evaluated carefully for urethral, bladder and prostate disease.
  • Older dogs need to be screened thoroughly for bladder infections, stones and cancer.
  • Male or female dogs who develop incontinence at less than 1 year of age should always be evaluated for developmental abnormalities.

What Exactly Is Spay Incontinence?

A certain amount of muscle strength in the urethral sphincter is needed in order to prevent urine leakage.

After a female dog is spayed, the strength of the urethral sphincter decreases in the year following surgery — and it often continues to weaken with age. Approximately 20 percent of spayed female dogs will develop incontinence within three years of being spayed

Larger dogs are more likely to develop spay incontinence than smaller dogs. And canines who are spayed before their first heat have a lower incidence of spay incontinence, but spaying before 3 months of age appears to increase the incidence of its development.

How Do You Treat Spay Incontinence?

Urethral sphincter strength can be improved with medication — some 50 to 60 percent of incontinent spayed female dogs will respond to estrogen therapy, which works to increase the sensitivity of the closure receptors in the urethra.

Estriol (Incurin) is a new, natural estrogen therapy option that will be available to veterinarians this fall. Although other estrogen formulations have been used for spay incontinence, estriol is the only FDA-approved estrogen for the condition. (FDA approval ensures drug safety and effectiveness, as well as quality and consistent manufacturing and monitoring processes.)

Another course of treatment is phenylpropanolamine (PPA), which is a nonhormonal medication that directly stimulates closure receptors in the urethra. About 85 to 90 percent of spayed female dogs will show an excellent response to PPA. The FDA has also recently approved a PPA product called Proin for the treatment of spay incontinence.

If incontinence fails to respond to either estrogen or PPA alone, it is recommended that both therapies be used simultaneously, since they often work better together. 

Are There Other Treatments for the Condition?

Medication works for most dogs with spay incontinence, but when it fails or a dog experiences adverse side effects from the medications, there are other procedures that can be considered. These include collagen or bulking injections around the urethral sphincter, surgical implantation of a urethral occluder and certain bladder and urethral tacking surgeries.

While some of these therapies have proven successful, these techniques will not necessarily provide lifelong continence, and a combination of surgical and medical options are often used jointly for the best outcome.

Dr. Donna Spector is a board-certified internal medicine specialist who practices in the northern Chicago area. She also owns a consulting business that focuses on bringing specialty veterinary care to underserviced regions, providing consultations directly to pet owners and their veterinarians.