Sometimes your cat turns his back on the litter box. But, why?

A cute little 7-year-old cat came into the clinic last week. She has a history of periods of inappropriate urination (she pees on beds and other furniture). The owner brought the cat to the clinic to rule out a urinary tract infection.

There are many possible reasons for a cat to urinate where it should not; some are primarily medical, some are primarily behavioral, and one is in between. The most common medical causes are urinary tract infection, bladder stones, bladder cancer, and orthopedic pain (like arthritis). Behavioral causes include territorial spraying/marking and rejection of litter box due to cleanliness, location, competition, or litter choice. One diagnosis that spans both categories is feline idiopathic cystitis (FIC; sometimes called feline interstitial cystitis). Our goal in these cases is to rule out the medical causes before we begin to explore the behavioral ones and FIC.

Medical Causes. The diagnosis of medical causes starts with a good history from the owner. If there are stones, bladder cancer, or a raging urinary tract infection, the cat will likely strain while urinating, have trace amounts of blood in the urine, and urinate in several small amounts rather than one large puddle. If the cat is arthritic or has other reasons it can’t get to the box, there will be other signs the owner can see and the cat will likely not use the box at all. Treatment is based on the specific diagnosis: antibiotics for a urinary tract infection, stone removal, chemotherapy, pain control, etc.

Behavioral Causes. Once medical causes are ruled out, we turn to the behavioral ones. If the cat is spraying territorially, there will be urine on vertical surfaces, usually in a high-traffic or particularly coveted spot. If not, we look to the litter boxes themselves. Are they clean? Are there enough of them and are they located wisely? There should be one for every cat in the house – plus one! And, they should be in many different, quiet locations throughout the house. This way, there is no competition for them and the dominant cat cannot prevent access by the others. Litter choice is pretty easy to rule out: if you bring home a new litter and one or more cats suddenly refuse to use the boxes, the message will be clear. If behavioral causes are diagnosed, changes can be made in the home and medications can be prescribed.

FIC. Some indoor cats develop an inflammation of the bladder lining for reasons that have not been completely determined. The clinical signs of FIC are those of urinary tract infections, cancer, or stones, as described above. But, bacteria are rarely seen in the urine and stones and cancer are not present. Diagnosis is based on excluding medical and behavioral causes.

There are three factors currently believed to be implicated in FIC: defective bladder lining, stress, and diet. Affected cats have been noted to have a defective protective layer within the bladder; without this layer, urine is very irritating and can cause inflammation and injury. Some cats appear to be more sensitive to life changes and other stressors than the average cat. These cats can be sensitive to such things as new homes, addition or loss of family members, visitors, severe weather, and illness.

The treatment plan for FIC cats focuses on stress relief and diet change. To reduce stress, the owner should make sure the cat has access to sufficient resources: food and water dishes, clean litter boxes, a quiet place for escape, desirable viewing areas (some near windows), appropriate toys, and a quality scratching post. The owner should also plan to spend quality time petting and grooming the cat. Medications can be used in the beginning, while the environmental changes are being made. The diet recommendation is to introduce canned food and to encourage increased water consumption.

What about our Patient?

History: She is an indoor cat and there are two other cats in the house – one adult who is dominant to our patient, and a kitten that moved in about three months ago. There is a recent history of human housemates moving in and out. Her owner is frequently away, leaving the cat with the other two housemates. Periodically, the cat will pee (in large quantities) outside her litter box, mainly on a housemate’s bed where she also prefers to sleep. In the house, there are multiple food and water dishes, as well as two litter boxes (one very large one and one very small one). This is a young cat, with no history of arthritis or other inability to use its littler box.

Physical exam: There was nothing unusual noted on her physical exam.

Diagnostics: We performed a urinalysis. The specific gravity was high at >1.060, which may suggest that she was slightly dehydrated. On microscopic examination of her urine, there are no red blood cells, rare white blood cells, rare crystals, and no bacteria noted. The dip stick we used showed nothing outside the normal range. We decided that, given the lack of blood in the urine and the cat’s history of voiding her whole bladder when she pees on the bed, we would not pursue bladder stones or cancer.

Which behavioral causes can we rule out? We know that she’s not spraying, because she is peeing on horizontal rather than vertical surfaces. The litter boxes are kept clean and she has no trouble with the litter when she does use the boxes. The number and locations of the litter boxes are certainly not ideal: the rule of thumb is that there should be one litter box for each cat in the home – plus one extra. This enables every cat to find a box conveniently and not be kept away by a more dominant feline family member intent on guarding the one box. So, our patient’s urination may have something to do with having to compete for this scarce resource with a more dominant adult cat. And, we can’t rule out the role of the recent stressors: changes in humans living in the home, a new kitten, etc.

Is it FIC? Probably not at this time. We did not see clinical signs of a urinary tract infection, just inappropriate urination. But, this cat may become an FIC candidate if the stress is not controlled.

Treatment: The owner will correct the litter box situation and add more desirable perches. We prescribed a human anti-anxiety medication called amitriptylline to help reduce the cat’s stress while her environment is being changed. We started with a very low dose and are hoping to take her off it completely in the next month or so.

Because so many cats are relinquished to shelters for inappropriate urination, it is important for owners to know when to seek help and what to expect. Often, there are no clear answers early in the diagnostic process, so patience is important. And, should the cause be behavior or FIC, the treatment can be slow and involved. But, successful treatment allows feline and human family members to relax and live happily together.

A Note about this Post: I receive a comment or two every day about this post. I have decided not to allow any more for three reasons: First, the questions are all very similar in nature and I find myself giving the same answer time after time. Second, I really cannot diagnose your cat over the internet. And, third, everything you need to know, from diagnostics through treatment, is given here and in a similar post ( If you have ruled out medical problems, have really tried all the environmental changes recommended in these two posts, and still have a problem, another trip to the vet is definitely warranted.