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Urinary incontinence is when your cat is unable to control (and may be unaware of) when he or she urinates. Thankfully, this is a far less common issue in cats than in dogs.
Normally, urine is produced in your cat’s kidneys and travels through two tubes called ureters into the bladder. As the bladder fills with urine, it distends and stretches. When your cat urinates, he or she relaxes the sphincter between the bladder and the urethra, the tube that allows urine to exit the body. A malfunction or problem anywhere along the urinary tract can potentially lead to incontinence, or leaking of urine.
Symptoms
Symptoms of urinary incontinence include:
- Inflamed, irritated skin around the penis/vulva
- Leaking urine
- Puddles of urine where your cat sleeps
- Recurring urinary tract infections
- Urine outside the litterbox
- Wet hair between the hind legs or around the penis/vulva
Causes
A variety of conditions can cause urinary incontinence in cats. In most cases, the problem is related to the cat being unable to or having difficulty storing urine, but it can sometimes be due to problems urinating. Luckily for us, incontinence due to any cause is rare in cats.
Ectopic ureter(s) is a condition in which a kitten is born with one or both ureters that bypass the bladder. This results in urine running directly from the kidneys out of the body, without anything in the way to stop or store it. This can be fixed by surgically connecting the ureters to where they are supposed to attach to the bladder.
Urethral sphincter mechanism incompetence (USMI) is when the urethral sphincter that controls when urine exits the bladder isn’t doing its job properly. The sphincter may be too loose all the time, resulting in chronic leaking of urine, or it may be weaker than it should be, allowing urine to push through when the bladder starts to fill up. USMI is more likely to show up at a young age in cats than in dogs, and affected cats often have other physical abnormalities present in the urinary tract.
Nerve damage usually occurs during a traumatic event such as being hit by a car or attacked by a dog. If the nerves that control bladder function are damaged or severed, your cat will not be able to urinate normally.
Obstruction due to bladder stones, urinary tract infections, or cancer can lead to incontinence by preventing normal function of the urinary tract. Blocked cats may experience nerve damage or damage to the urethral sphincter due to the high pressure in the bladder, resulting in incontinence after being unblocked.
Feline leukemia virus can sometimes cause incontinence.
Urinary tract infections may cause your cat to feel the urge to urinate more frequently, resulting in leakage and/or house soiling.
What You Can Do
Note changes in urinary habits. Note how often and how much your cat urinates. If urine is showing up outside the litterbox, pay attention to where the accidents occur. A puddle in your cat’s bed or a trail of dribbles where she walked down the hall are some of the more common signs of urinary incontinence. You may also simply notice that your cat is frequently damp around the penis or vulva or that your cat is grooming those areas more often.
Take your cat to the veterinarian. This is the single most important thing you can do if you notice that your cat is urinating when and where she shouldn’t or that she is dribbling urine. Even though this may very well be due to a urinary tract infection, identifying the problem swiftly will allow you to help your cat by pursuing the optimal treatment.
Ask about treatment side effects. Knowing potential side effects ahead of time allows you to be prepared and to keep an eye out for any signs of a problem.
Diagnosis
Getting an accurate diagnosis for urinary incontinence can be challenging, and often we are unable to determine the underlying cause. Your veterinarian will need a thorough history of your cat’s urinary habits and any changes, and will start out by palpating the bladder as part of the physical exam and running a urinalysis to check for signs of infection or abnormal cells. A urine culture can be helpful as well, especially if your cat has been experiencing recurring UTIs.
The size of your cat’s bladder over time can help provide clues to what is going on. A “big bladder” indicates trouble with urinating, while a “small bladder” indicates trouble with storing urine. Normally your cat’s bladder will fluctuate in size depending on how recently he urinated, but if it is chronically large or small, that may be significant.
Diagnostic imaging that allows your veterinarian or a specialist to see the urinary tract includes radiographs (x-rays), ultrasound, and CT or MRI.
Your veterinarian may also recommend doing tests to measure your cat’s urine output and the pressure within different parts of the urinary tract. It is even possible to test the electrical output of the muscles involved in urination and urine storage to help determine where the problem is occurring.
Advanced testing isn’t always available or practical for many cat owners. In these cases, your veterinarian may opt for a less elegant but often effective approach: Choose a treatment plan based on clinical signs, try it out, and see if it works.
Treatment
Physical abnormalities, such as ectopic ureters or abnormal anatomy in the bladder, urethra, penis, or vagina, can often be repaired surgically.
USMI is often treated medically. There isn’t much research on treating incontinence in cats, so many medications are used off-label based on their effectiveness in dogs and other species. Perhaps the most common option is phenylpropanolamine (Proin). The most common side effects of this medication in cats include tachycardia (abnormally fast heartbeat), hypertension, and restlessness. Estrogens are another option, but should be used with caution in cats due to the risk of side effects such as bone marrow suppression and mammary cancer.
Manual expression of the bladder can be helpful in some cases if the cat is not able to fully empty his or her bladder on their own. By completely emptying the bladder, there will be less urine present to leak, and it will take longer for the bladder to fill back up again. The medication bethanechol is sometimes used off-label in cats to promote stronger contractions of the bladder and complete emptying during urination.
In an emergency situation or while pursuing a diagnosis, your veterinarian may place a urinary catheter to drain the bladder and/or track urine volume.
A new option for treatment of urinary incontinence is surgically implanting an inflatable silicone hydraulic occluder that acts like an artificial sphincter. A study published in the Journal of the American Veterinary Medical Association in 2016 described using this implant in three cats with urinary incontinence. All three cats had urinary control after the procedure, and while one had to have the device removed later due to complications, the other cats continued to do well for three and six years, respectively.
