Pet Pause: How to deal with a cat that refuses to use litter box

Litter boxes are best placed in a quiet area and with no cover, at least to start. Boxes need to be at least 1.5 times the body length, and sides may need to be cut lower for kittens and older, arthritic cats to easily get in and out of.

If a cat develops an aversion to using a litter box, an anti-anxiety medication is warranted. Try various litter box types and litter locations. A litter box additive called Cat Attract adds an earthy scent that may be helpful.

To discourage a cat from using an inappropriate surface, the surface needs to be cleaned and a deodorizer used repeatedly. Wall-to-wall carpeting may need to be replaced. Applying a strong citrus scent such as lemon-scented soap to the surface will make it less appealing, as will covering it with thick plastic sheeting, a plastic carpet runner with nubs up, double-sided sticky tape or a motion sensor with compressed air (SSSCAT). Some cats will not eliminate where they are fed, so place food dishes on the inappropriate surface.

Behavior modification

Behavior modification is going to be important regardless of the cause of the problem – behavioral or medical. It is imperative to rule out medical problems first. Medical problems can include a bladder infection or stone, increased water consumption due to an illness or, more commonly in older cats, arthritis. An incompletely understood condition called feline idiopathic cystitis can lead to inappropriate urination, straining to urinate, increased urination frequency and oftentimes blood in the urine.

If the problem is determined not to be medical and correction of a litter box aversion is unsuccessful, then an anti-anxiety medication is likely needed.

House soiling needs to be distinguished from marking behavior and may be difficult to distinguish in some cases. Urine marking can include urinating on a vertical surface; urinating on new furniture, dirty laundry or a bed; urinating near a door or window; and still urinating sometimes in the litter box and sometimes following a change in the household, especially a new pet or person.

In the case of urine marking, the earlier anti-anxiety medication is started, the more likely the problem will be controlled. While the medications are very safe and generally given just once a day, it may take two months or more to determine their effectiveness.

A cat may mark due to presence of other cats both inside and outside of the home. Marking can occur in response to stress or anxiety and is most common when there are three or more cats in the household. If the problem is due to social interactions inside the home, it may be necessary to determine which cats do not get along. Keep these cats in separate parts of the home with their own litter and sleeping areas. Allowing the cats together for positive experiences, such as feeding, treats and play sessions, helps them get used to the presence of one another.

Again, with marking behavior, anti-anxiety medications need to be started immediately and any social concerns addressed to have the best chance of success. After several months of marking behavior, anti-anxiety medications may not be helpful, as it becomes a learned behavior.

As a last resort, confine the cat to a small area such as a large plastic carrier with a litter box. After the cat consistently uses the litter box, expand the cat’s access to a larger area such as the bathroom and then a larger room, etc., until it is allowed full access.

Many people waste time and effort on the wrong approach until they want to get rid of their cat. Even if your cat occasionally eliminates inappropriately, please contact your veterinarian promptly.

Dr. Kenton Taylor is a veterinarian with Miramonte Veterinary Hospital, 1766 Miramonte Ave., Mountain View. For more information, call (650) 962-8338 or visit miramontevet.com.