Pet Care

Medical Causes of House Soiling in Cats

cat being examined by veterinarians

House soiling, or inappropriate urination or defecation, is a common problem in cats. While in many cases the cause is a behavioral problem, sometimes medical issues are to blame. If your cat eliminates outside the litter box, she should be checked by a veterinarian for an underlying medical condition before it’s determined that the inappropriate elimination is due to a behavior problem. In addition to a complete physical examination, your cat should have a complete blood count, blood chemistry panel and urinalysis. Other tests, such as radiographs that use special dyes to outline the urinary tract, may be necessary as well. If an underlying condition is determined to be the cause of your cat’s house soiling, the medical problem should be treated, and her response to treatment should be closely monitored. Once any medical problems are treated, you may still need to retrain your cat to reestablish normal litter box elimination patterns. Please see our article, Litter Box Problems, for additional help.

Inappropriate Urination

There are several disorders that can be responsible for a cat not using her litter box. Some of the most common medical causes follow.

Bacterial Bladder Infection

Bacterial bladder infection, or bacterial cystitis, is common in cats. (In rare instances, the infection may be due to a fungus rather than bacteria.) Because the infection causes inflammation of the bladder, a cat with this medical problem feels a constant need to urinate. The urge to urinate may become so strong that she urinates small amounts frequently, often before she can reach the litter box. Certain conditions, like bladder stones, bladder tumors, defects in the shape of the bladder and diabetes, may make bladder infections more likely to occur. Female cats are more likely to be affected than males.

Cats suffering from bacterial cystitis may squat frequently to urinate but produce only a small amount of urine. They often continue to strain, even after they’re done urinating, and they may cry out while straining. Their urine may appear red in color due to blood. Cats suffering from bladder infections may also show signs such as not eating, lethargy or hiding.

The diagnosis is made by testing your cat’s urine for the presence of red blood cells, white blood cells and bacteria. In some cases, your cat’s veterinarian may have her urine tested in a lab to determine the specific bacteria involved, which will better guide therapy. Once a diagnosis is made, your cat will be started on a course of antibiotics that may last several weeks. If the condition recurs, your cat’s veterinarian may recommend special tests, such as radiographs and dye studies, to look for another cause for your cat’s cystitis.

Feline Lower Urinary Tract Disease (FLUTD)

FLUTD is a common condition in cats. Although it has many of the same signs as bacterial cystitis (frequent urination, straining to urinate and bloody urine), there’s no bacterial infection. In most cases, no cause for the condition can be determined. Stress, multiple cats in the household and eating dry foods, which reduces urine production, may increase a cat’s risk of developing FLUTD. It’s more common in male cats, who may develop an obstruction of their urinary tract that makes it impossible for them to urinate. This is a medical emergency that needs immediate veterinary care.

Diagnosis of FLUTD is made by ruling out the other causes of cystitis. The signs may resolve on their own within a week without treatment, but they’re likely to recur. Treatment may involve many different strategies. One treatment, environmental enrichment, may decrease the rate of recurrence by 80%. Enrichment involves making various changes in your cat’s life to provide her with ample mental stimulation. This can make her more likely to use her litter box. Giving your cat more toys, increasing her access to windows and glass doors so she can see outside, and spending more time petting and playing with her may be helpful. Please see our articles, Enriching Your Cat’s Life and Cat Toys, for additional fun ideas for livening up your cat’s life. In addition, you may need to increase the number of litter boxes in your home. There should be one litter box per cat, plus an additional box. Unscented litter should be used. The box should be scooped at least once daily and thoroughly cleaned at least once a month with an odorless cleaner. (Avoid using harsh cleaners, such as products containing bleach or ammonia.)

Medical treatment and dietary changes may also be needed to resolve the symptoms of FLUTD. Feed your cat canned food to increase her water intake, and make fresh water available at all times. Some medications may be useful during flare-ups of FLUTD or to reduce long-term symptoms. Drugs to relieve stress and anxiety or to reduce pain and bladder inflammation may be useful for cats who don’t respond to environmental enrichment.

Urinary Incontinence

A cat suffering from urinary incontinence loses the ability to control urination and dribbles urine. She may also leave a urine spot where she’s been sleeping. Urinary incontinence may be due to many causes that affect the bladder or the urethra, such as injury or a tumor of the spinal cord. Your cat’s veterinarian will do a complete work-up, similar to that for cystitis. Additional tests may be needed. Treatment depends on determining the underlying cause and then correcting it or giving medications to prevent the incontinence.

Increased Urine Production

Many diseases can increase the amount of urine a cat produces and lead to urinary accidents and an increased need to urinate. Conditions that may cause increased urine production include:

  • Kidney failure
  • Kidney infection
  • Diabetes
  • Liver disease
  • Increased thyroid hormone levels

Unlike cats with cystitis, cats with increased urine production generally void large amounts of urine without straining. Other signs may include increased water intake, poor appetite, weight loss and poor hair coat. Cats showing these signs need to be seen by a veterinarian to have a thorough work-up. Treatment depends on the cause of the increased urine production.

Inappropriate Defecation

Inappropriate defecation due to medical reasons is less common than inappropriate urination in cats. Even so, if your cat has defecates outside the litter box, she should be thoroughly examined by a veterinarian, who will run appropriate tests.

Conditions that cause diarrhea may increase urgency, causing a cat to defecate before she can make it to her litter box. So it’s important to determine if your cat is passing normal stool or some form of diarrhea. There are many causes of diarrhea, some of which may be temporary or intermittent. Severe constipation can also cause incontinence. Cats with severe constipation may frequently strain to pass stool and do so in an inappropriate place.

Fecal Incontinence

In fecal incontinence, a cat loses the ability to control defecation and may leave stool in random places around the house. This problem is usually caused by nerve damage—due to injury or a tumor of the spinal cord, for example—that prevents the normal control of defecation. Any cat who suffers from fecal incontinence should have a diagnostic evaluation by a veterinarian to determine the cause of the problem.