Dr. Jeff Grognet DVM & Dr. Louise Janes DVM — April 2011
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Light Therapy for Incontinence
by Jeff Grognet, DVM, BSc (Agr) and Louise Janes, BSc(Agr), DVM
As we do more and more light therapy at the hospital and seeing some wonderful results, we are using it on a diverse mix of ailments. The main thrust of this therapy has been for pain due to musculoskeletal problems. However, we are seeing it work with inflammatory bowel disease, skin diseases, and even gum disease. In this issue, we feature a dog that had urinary incontinence problems that was not being controlled with conventional therapy.
This case involves an 11-year-old Belgian Malinois, spayed female.
This patient came to see us because of her urinary incontinence. This 60 pound dog was on 1 mg stilbestrol every 2nd day, however, she still leaked every night. Her vulva was swollen as a side effect of the estrogen hormone.
When she was examined, she showed pain when her lumbar spine was palpated. She had back pain.
I stopped her medication and started light therapy. We set the frequencies to address the two ailments – the pain in her spine and her continued incontinence. In all, 7 treatments were done, two the first day, 2 two days later, and three more separate ones over the next week.
The incontinence ceased after the first day of treatment. After two days of treatment, she was jumping at the door to go out (she hadn’t done this for years).
After the seven sessions, we determined that it was time to stop the treatment. We’ll just wait to see how things go. We have many dogs that we treated last fall that have not needed to come back for treatment.
You may wonder how this works. The frequency we use in the light therapy heads signals the nerves to start functioning again. In this case, it is the nerves that supply the valve on the urethra.
The resource below provides more information on incontinence and it also reviews the standard (conventional) treatment.
Incontinence
Forty years ago, most dogs lived outdoors and the closest they got to the house was the porch. If these dogs couldn’t control their bladders, it wasn’t an issue. In fact, if dogs were incontinent, many owners never knew. It’s different now. Our dogs share our living rooms, bedrooms, and even our beds. Urine dribbling is a serious crime when a dog sleeps on a down duvet. Fortunately, most cases of incontinence can be diagnosed and easily treated.
Incontinence is defined as an involuntary escape of urine from the bladder. An incontinent dog can urinate normally, but in-between voiding, she dribbles urine intermittently or continuously. To understand why this occurs, an anatomy lesson is in order.
The kidney is the prime excretory organ. It removes toxins from the bloodstream and, in doing so, forms urine. Urine exits each kidney and flows into the bladder via its own ureter. The bladder is a low pressure storage vessel lined with strong muscles that contract to push urine out during voiding. Urine exits the bladder through a single tube called the urethra which empties inside the bitch’s vagina. The final exit for urine is therefore from the vulva.
Urine is held in the bladder by a muscular valve called the urethral sphincter – a ring kept closed by muscle contractions. Constant tone in the muscle is maintained by nerve impulses from the spinal cord. If the muscles are unable to keep taut, urine leaks out of the bladder into the urethra, and ultimately out the vulva.
The intricate neurologic input to the urethra changes from moment to moment. In some instances, the muscles need to contract harder to increase the tension in the sphincter. Imagine what would happen if the urethral sphincter did not tighten during a sneeze. If it didn’t clamp down at that moment, the intense abdominal pressure would transfer to the bladder and send urine squirting through the urethra.
In contrast, when urine is being voided, the sphincter tension decreases. The nerve messages are altered so that the muscles in the sphincter relax while muscles in the bladder wall contract to propel urine down the urethra.
Incontinence results if the sphincter fails to stop urine flow when there is normal pressure in the bladder.
When a veterinarian tries to determine the cause of urine leaking in a bitch, she starts by asking questions. Is it continuous? If it is and if it started right after birth, it could be a congenital anomaly. If it began later in life, it could be related to being spayed. Does the bitch leak all the time or only when she is asleep? Is it aggravated by deep sleep or excessive exercise?
A young dog that has continuous urine dripping may have an anomaly called an ectopic ureter. In this case, a ureter empties directly into the urethra (or vagina) instead of into the bladder. It bypasses the urethral sphincter so even if the muscles of the sphincter are working well, urine flows without control into the urethra. Most cases (about 75 percent) are unilateral (only one side involved) while others have both ureters are involved (bilateral ectopic ureters).
Puppies with ectopic ureters often develop bladder infections which prompt a veterinary visit. Unfortunately, the incontinence is sometimes blamed on the infection. Only when the incontinence fails to clear up as the infection is resolved is an ectopic ureter suspected.
Ectopic ureters are diagnosed by giving an intravenous injection of a dye that spills into the urine. As the dye exits each kidney, a radiograph is taken to reveal the paths of the ureters. Another technique called a cystoscopy (putting a scope up the urethra into the bladder) can also be utilized to determine the location of the ureter exit.
Ectopic ureters can be corrected with surgery. The surgeon moves the ureter so it empties into the bladder. This procedure is not 100 percent effective and the incontinence persists in about one-half of dogs. As well, many dogs with ectopic ureters have concurrent kidney disease. For this reason, surgery should not be done until renal function has been evaluated.
The most common reason for incontinence is, thankfully, much easier to manage. Urethral sphincter incontinence, or what some veterinarians call a “leaky valve” affects between five and nine percent of spayed female dogs. These bitches usually start being incontinent two to three years after an uneventful spay, though in rare cases, it can arise just a few weeks after surgery. Urine dribbling is most noticeable when the dog is sleeping and aggravated by hard physical exercise.
It is not known how removal of the ovaries leads to incontinence. One hypothesis is that elimination of estrogen results in a poorly responsive urethral sphincter muscle. In other words, nerve stimulation alone does not have the ability to control the muscle – hormonal influences are also needed. This theory is supported by the fact that many dogs become continent when they are supplemented with estrogen.
Diagnosing urethral incontinence is very difficult. The veterinarian must measure the pressure in the urethra to tell how well the muscle is contracting. This takes specialized equipment. Rather than doing tests, many veterinarians put their patients on medication and see if they respond. If the bitches become continent, the disease is confirmed.
The preferred drug for treating sphincter incontinence is phenylpropanolamine (PPA). At least 85 percent of incontinent dogs stop urine leaking when given this medication. In other dogs, a significant decrease is reported.
Side effects of PPA include hypertension, restlessness, irritability, tachycardia, changes in glucose metabolism, and increased intraocular pressure. PPA should not be used in dogs with hypertension, diabetes, or glaucoma.
If a dog does not respond to PPA, the female hormone estrogen may help. Diethylstilbestrol (DES) is the form of estrogen used by most veterinarians. PPA and DES can be given together. Once the incontinence resolves, the dose of the PPA is reduced to the lowest amount that controls the condition.
Unfortunately, stilbestrol has side effects, some of them potentially serious. These include bone marrow suppression (it shuts down production of the red blood cells), alopecia, behaviour changes, and signs consistent with estrus (swollen vulva).
If medication is not effective or not desired, surgery can be tried to improve the function of the failing urethral sphincter (see sidebar). Alternatively, acupuncture has been used to manage incontinence in dogs. The mechanism of how this therapy works is unknown, but it does appear to be beneficial with no reported side effects. Many dogs can be kept continent with a treatment every four to six weeks.
For more information contact Dr. Jeff Grognet or Dr. Louise Janes at
Mid-Isle Veterinary Hospital
5-161 Fern Road West
Qualicum Beach, B.C.
Tel (250) 752-8969