Incontinence is defined as abnormal voiding behavior showing a loss of voluntary control over the act of voiding with inappropriate urination. It should be distinguished from housetraining lapses and psychological causes.
One cause of incontinence may be an ectopic ureter-an abnormality in development in which instead of attaching to the bladder in the normal location, the ureters may attach very close to the neck of the bladder or even directly to the urethra, therefore bypassing the control sphincters. Since this is a congenital defect, signs are usually noted in cats under 1 year of age. Surgery may be attempted to move the ureter to a more normal location, or the kidney and ureter on that side may be removed. Cats do quite well with just one normal kidney.
Problems that affect a cat’s lower urinary system often prevent the bladder from emptying correctly or may even cause fatal blockage of the urethra, the tube connecting the bladder to the outside of the body. Very often the culprit is Feline Lower Urinary Tract Disease (FLUTD). Once called Feline Urologic Syndrome (FUS), FLUTD is not merely one problem, but a collection of clinical symptoms that may have more than one possible cause. Symptoms of FLUTD include frequent or painful urination, bloody...
When urinary incontinence is associated with FLUTD, the cat may at first experience sudden urges to void, urinate in locations other than the litter box, and void frequently in small amounts. These symptoms are caused by urgency and pain upon urination, but the cat retains some control over the act of voiding. However, if obstructions recur, the repeatedly overdistended bladder loses the ability to contract and empty. A more or less constant dribbling of urine occurs from the inert, overloaded bladder.
Spinal cord injury, especially that associated with pulling apart the sacral-lumbar or coccygeal vertebrae when a car runs over a cat’s tail, is a common cause of bladder paralysis, overdistension, and subsequent urinary incontinence. Spinal cord diseases and brain diseases can also lead to loss of bladder and bowel control. The spinal cord defect sometimes seen in Manx cats and associated with their tailless gene may also cause incontinence. Dysautonomia is an unusual neurological problem that often presents with incontinence as one of the signs. Incontinence related to these problems may improve if the primary condition responds to therapy.
Geriatric cats may lose some or all of their control over urination and leak, especially when sleeping. Cats suffering from feline leukemia sometimes show incontinence, as well.
Treatment: Treating incontinence is directed at finding the underlying cause and correcting it if possible. Drugs that act on the bladder muscle may be useful in selected cases.
WebMD Veterinary Reference from "Cat Owner's Home Veterinary Handbook"