Urinary incontinence is a common disorder in older female dogs, as many as 20% of neutered bitches develop it at some point in their lives. The reason is usually urethral sphincter mechanism incompetence (USMI). It can happen to any breed, though Boxers, Dobermanns and Collie breeds are particularly susceptible. In this article we review the current state of knowledge on this condition, focusing on the management and treatment options.
What is Urethral Sphincter Mechanism Incompetence (USMI)?
Affected bitches that are affected by this have poor tone to the smooth muscle surrounding their urethra (the tube that connects the bladder with the vagina), and often a shorter urethra than normal, and a bladder neck that is positioned Self-adhesive tape too far back in the abdomen.
There are a number of contributing factors to this condition developing, but the main ones are breed susceptibility, obesity, body size, bladder position and spaying (neutering). Spaying is thought to have an effect by decreasing the estrogen levels, which affects the local muscle tone. However, most spayed bitches do not develop the condition and it should certainly not be used as an excuse not to neuter, as the increased likelihood of cancer in non neutered bitches is far more worrying.
What are the clinical signs?
The disorder is characterized by the passive leakage of urine without the dog noticing, often during sleep or rest while the dog is lying down.Polyester taffeta The owner usually remarks how there is always a stench of urine coming from the dogs bedding, and how the dog seems permanently wet and smelly around the back end. Continual leakage can also cause scalding of the skin around the vulva and groin.
How is it diagnosed?
Diagnosis is usually made based on the history. The pattern of urination is important to rule out other causes of incontinence. Urinalysis, radiography and ultrasonography can be performed for confirmation if necessary (e.g. to assess the location of the bladder neck within the abdomen).