Today, I’d like to discuss urinary incontinence in female dogs. It’s rarely an issue for male dogs nor for felines of either sex, but urinary incontinence is not uncommon in female dogs. Since you are receiving this email, you likely have a diabetic pet. Urinary accidents in the home are one of the greatest complaints from diabetic pet owners. A pet with urinary incontinence that produces greater volumes of urine may have a greater likelihood of exhibiting urinary incontinence.
The typical presentation of urinary incontinence is a pet who leaks urine in her bed where she is laying down or sleeping. Urinary incontinence now has the fancy name of primary sphincter mechanism incompetence (PMSI), but it used to be known as hormone responsive or spay-related incontinence. Sometimes I make the initial diagnosis when a pet presents for a urinary tract infection and the owner mentions that she has been wetting the bed for some time. In fact, pets with urinary incontinence are predisposed to urinary tract infections because the area around their private bits stays wet and bacteria can ascend into the urethra. Bigger dogs are more likely to become incontinent than little dogs and age can also play a role in declining urethral tone.
People may hear the phrase hormone responsive or spay-related incontinence and worry about spaying their dogs. Let’s not think we should avoid spaying our female dogs! Although the lack of estrogen may very slightly increase the risk of urinary incontinence a few years after the ovariohysterectomy, the lack of estrogen when spayed dramatically decreases the risk of mammary cancer in dogs. Additionally, we avoid unwanted pregnancies and heat cycles and uterine infections when we spay a dog.
Some pets of predisposed breeds may present with urinary incontinence even if they are not spayed. If we adopt a dog when she is young, the risk of incontinence if the puppy is spayed between 3 and 6 months of age is the same as if the pet was never spayed. Pups spayed before 3 months of age have an increased risk of urinary incontinence compared to dogs spayed between 3 and 6 months of age. Dogs spayed between the first and second heat cycle (nearly always after 6 months of age) also have a slightly increased risk compared to dogs spayed between 3 and 6 months of age. Traditionally most veterinarians will spay a puppy around 5 or 6 months of age. The take home message is this: spay your puppy between the 3 and 6 months of age to decrease the chance of urinary incontinence, particularly if you have a predisposed breed such as a dobie or giant schnauzer.
So, how do we treat urinary incontinence? It is usually managed quite well medically with the administration of medications that increase the urethral tone.
Phenylpropanolamine (PPA) – PPA increases the urethral tone and is often the first choice medication for urinary incontinence. It can be given once a day in the evening for pets who only leak at night or two to 3 times daily for more severely affected dogs. Unfortunately, pets with heart or kidney disease or high blood pressure should avoid this medication.
Estrogens – Estriol is a rapidly absorbed oral estrogen that received FDA approval for PSMI in North America in 2011. It has a success rate similar to PPA with about 90% of dogs responding to it. Estriol has fewer side effects and a greater efficacy than DES which is the estrogen that vets used for incontinent dogs for many years. Side effects to oral estrogens are not common if tapered to a minimally effective dose regime. The worst potential side effects of estrogen use is bone marrow suppression. This side effect is uncommon but vets typically check complete blood counts twice yearly when a pet is on estrogen because of this potential issue. It is important to decrease the frequency of dosing until the pet owner finds the minimal effective dose that controls the incontinence.
What if medications don’t work?
New techniques have been successful, but these are done at large referral hospitals rather than your local veterinary clinic. Collagen injections around the urethra under general anesthesia and even an artificial urethral sphincter implantation have shown success at the Ohio State University. There is probably a joke in here somewhere about dogs getting collagen injections where the sun doesn’t shine, but I will abstain.
If you do happen to have a diabetic dog that also experiences urinary incontinence, getting the diabetes regulated will result in an improved situation! The closer the blood glucose values are to normal, the less urine is produced. Less urine production results in fewer episodes of leaking urine for incontinent pets.
NOTE: Consult your veterinarian to confirm that my recommendations are applicable for the health needs of your pet.