My cat suddenly has begun defecating on my bedroom carpet instead of in the litter box. What can I do to stop this behavior?

A problem with many causes.

Unfortunately, this is one of the most common behavioral complaints of cat owners. There are several factors that may contribute to cats defecating inappropriately. Environmental or social stress, personal preferences or changes in personal preferences, or medical problems may cause this behavior. Although most feline elimination disorders are behavioral, to rule out a medical problem, your veterinarian will need to do a complete physical examination, urinalysis, and a fecal exam. If your cat is middle-aged or older, then the doctor may also opt to perform bloodwork including a complete blood count and a chemistry panel. Cats with feline lower urinary tract disease or cystitis may begin to defecate and/or urinate outside the litter box. It can be difficult to determine whether cats begin defecating outside of the box because they have developed a disliking to a certain litter, or to a location, as opposed to simply preferring to defecate in the new location. The development of a disliking or aversion to a particular substrate or litter is much more likely than avoidance of a particular location. Cats can develop an aversion to anything from clumpable litter, to an odor, to certain noises, to extraneous smells, and many other things. If possible, offer the affected cat a wide variety of different types of cat litter in a combination of different depths. You could try changing the litter and leaving the box in the same location. In addition, providing a second litter box in the area that has been chosen as the unwanted place to defecate may be helpful. Some cats require separate litter boxes for urination and defecation. Generally, if there are elimination problems in the house, each cat should have at least one box. And there should be at least one box per floor in multi-floored homes. Cats typically do not develop aversions to locations, but they may if the litter box is associated with the presence of any undesirable individual such as another cat, a dog, or a child. Perhaps your cat had a bad experience while at the previous litter box. Another pet could have disturbed your cat while it was defecating, causing it to have a negative association with the box. Also, if the litter box is close to a television, alarm clock, or other noisy object, your cat may have developed an aversion to defecating there. It is a good idea to place another litter box in a new location where your cat has begun defecating. You can use the same litter and the same box, or buy another box. If your pet begins to use the new box, then gradually move the box an inch each day until it is in a more desirable spot. If you move the litter box too quickly, however, the cat may relapse. In addition, if another pet begins tormenting the affected cat while it defecates in this new place, then the problem may begin again. Something else to consider is the personality of your cat. Shy cats may need a covered litter box. Another idea is to place your cat's food and water in the bedroom to see if this deters him; most pets will not defecate in the same area that they eat. You could also try a scat mat. These are sold at many pet stores, and they send a mild shock when an animal stands on them. Yet, although a scat mat may deter defecation in the bedroom, your cat may very well pick another inappropriate place. If your cat is medically normal, and other behavioral techniques have been exhausted, your veterinarian may recommend medical treatment with anti-anxiety medications. Consult your veterinarian about this problem for more information and suggestions. Veterinary behavioral specialists may offer additional insights.