Urinary Incontinence in Dogs
What is Urinary Incontinence?
Urinary Incontinence (UI) is the loss of control of the urinary tract. This causes the classical signs of dogs being unaware that they are urinating inappropriately. If your dog is urinating normally but inappropriately e.g. squats and urinates normally but indoors – this is NOT urinary incontinence. UI most often causes a low grade “leak” of urine from the bladder and, in females, this can cause permanent wetness around the rear end (vulva) and bed-wetting at night. More severely affected dogs can be seen to drip urine from their vulva/penis as they walk along.
Long-term UI causes irritation of the skin around the vulva allowing bacteria to infect this area and in fact a large proportion of the dogs that we see with UI have a history of long-term skin infections caused by UI.
UI is more common in female dogs than male dogs. Although some dogs can be born with UI due to some abnormality of the development of their urinary tract, most of the cases that we see have acquired UI that is, it has developed during their life and hasn’t always been there.
How is UI investigated?
Most specialists will have a good idea of the likely diagnosis from examining your pet, and examining his/her clinical notes and history. A few laboratory tests are usually needed e.g. blood and urine tests to ensure that there is no active urine infection (which can cause UI) and no internal reason why the bladder may be filling up too fast, causing an “overflow incontinence” as these conditions would be treated medically. Some form of diagnostic imaging is usually recommended and this may be ultrasound or, especially if congenital abnormality is suspected, CT scans of the urinary system. Sometimes a small camera is passed into the urethra and bladder (cystoscopy).
How is UI treated?
Any underlying medical or anatomical abnormality that is found during the investigations is treated. We would hope that the UI would improve or even resolve if the underlying disease can be eliminated. The most common cause of acquired UI, however, is a type of bladder neck weakness called USMI (Urethral Sphincter Mechanism Incompetence) and this is usually a diagnosis of exclusion. This means that there is no single, reliable test that we can perform to make this diagnosis. We have to show that there is no other likely cause of the UI and if everything else seems “normal” then a diagnosis of USMI is usually made.
Medical treatment of USMI
Most cases of USMI can be treated with medication. This is usually effective in 60-90% of cases and the medication is generally well tolerated but has to be given long term (for life). There is a low risk of adverse effects including restlessness and irritability. The aim is to control the UI rather than cure it.
Surgical treatment of USMI
Surgery is offered to dogs who have not responded well to medical management – either medicine has not worked or the animals have developed reactions to the medication. Surgery usually involves an abdominal wound through which the bladder is either repositioned thereby “stretching” the urethra or an Artificial Urethral Sphincter (AUS, see picture) can be placed to provide extra support around the bladder neck (urethra). The AUS is a permanent implant and, although relatively new, has shown to be very promising in cases that have not responded well to medical management.
USMI in Male Dogs
Although not affected as commonly as female dogs, USMI in male dogs can be very difficult to control. Medical management fails in the majority of cases and there are not many effective surgical options. Placement of an AUS is now the procedure of choice for these dogs with many dogs either becoming completely or at least much more continent (“normal”).
All investigations and treatment options will be discussed with you during a consultation with one of our surgical specialists.