Physical examination and blood and urine tests are usually normal in these pets. Hormone-responsive incontinence can occur months to years after a pet is neutered. As pets age they may become incontinent. This may be due to a weakening of the muscles that hold urine in the bladder. If a pet has one of these diseases and often has a full bladder, the full bladder can push against the weakened sphincter and cause incontinence.
Older pets can also develop senility and simply be unaware that they are dribbling urine.
Brain or spinal cord disease can cause a pet to lose control over bladder function. Dogs and cats with brain or spinal cord disease may either dribble urine or be unable to pass urine. Most often they will have other signs of nervous system disease such as muscle weakness or paralysis. Intermittent incontinence, primarily at rest, has been reported in cats of both sexes that are positive for the feline leukemia virus. How the virus causes incontinence is unknown.