When cats urinate in odd places like on a rug or in a sink, if they strain to urinate or urinate frequently, or if they excessively groom themselves in the perineal region or any combination of these behaviors, there is some reason for this behavior.
Is There a Medical Reason for This Behavior?
It is very important to rule out a medical urinary problem first. This is especially true with cats, neutered or not, since crystal formation and urethral inflammation can result in a life-threatening condition within hours.
Possible medical problems that relate to changes in urinary behaviors include a urinary tract infection or inflammation, blockage or partial blockage, kidney problems, or in the case of excessive thirst and urination, metabolic diseases such as diabetes. It is important to be familiar with the possible signs of a urinary tract infection.
Cats may urinate in unlikely places when stressed, such as a move, introduction of a new family member (human or animal), construction or remodeling in the house, and so on.
Your veterinarian will examine your cat, discuss the cat's behavior in the house, and do the appropriate tests, including an analysis of the urine. The urinalysis will check the concentration of the urine to make sure the kidneys are functioning properly and look for red blood cells, inflammatory white blood cells, and crystals. Your veterinarian may also recommend additional blood work or radiographs.
If your veterinarian feels that an infection or blockage is present, prompt medical treatment is necessary. In the event of a blockage or partial urinary blockage, minutes and hours count because urinary blockage can be fatal.
One Important Thing: the Litter Box
Cats that have had a urinary medical problem may continue to avoid their litter box even after the medical problem is resolved because they may associate pain or discomfort with the litter box. Or they may deem the box "too dirty" to use if they used it frequently. By doing a deep cleaning or getting a new litter box and then reacquainting your cat with using the litter box, these aberrant behaviors can be corrected.
Reacquainting your cat and modifying the litter box avoidance behavior requires patience, but a good start is a clean litter box and isolating the cat in a small space, such as a bathroom, with the litter box available. It is important to remove rugs and other materials that may be more tempting than the litter box.
Be careful with your litter choice as well—sticking with a non-perfumed litter that your cat is used to is a good start.
Consult with your veterinarian anytime you see your cat urinating outside of the litter box, urinating more or less frequently, or straining to urinate. Time is of the essence—calling sooner is much better than later. By paying attention to litter box habits and acting quickly if there is a problem, you just may save your cat's life.