When it comes to outside-the-litterbox toilet activity, some cats have a spread-the-wealth mentality; every place is fair game. But others develop an attachment to a particular place and will return to it over and over. Here are some ways to convince Kitty not to use a particular place in your house as a substitute litter box.
The first step is to get the spot as clean as possible. Cats rely extensively on their sense of smell, and the more that particular corner of the dining room smells like a litter box, the greater the chance it will be used that way. This can take some time, but it's absolutely essential. In fact in some cases getting the spot thoroughly clean can solve the problem.
Make sure your litter box is meets all the essential "cat criteria": is it clean, easily accessible, and located in a place that's quiet and private? Have you recently changed brands of litter? Try changing back to your old brand. Have you added a new cat to the household? Try setting up a second litter box. The more reasons a cat has to object to the box, the great the chance that she'll keep doing her business in an unauthorized area.
If your box is up to standard and the favorite spot is clean and odor free but the cat keeps returning to it anyway, try one of these solutions:
1. Put a litter box in that spot where the cat keeps urinating. This may seem like a real "if you can't beat 'em, join 'em" capitulation, but it's not. If you can get Kitty to use an approved box in that spot, you can gradually move the box away from the spot and hopefully Kitty will follow. Granted, a litter box under your desk may be inconvenient, but if the cat gets the idea and stops soiling the carpet, it's worth it.
2. Cover the spot. If you can cover the spot with something like a china closet, great. If they can't get to the spot they can't pee on it. If you can't make the spot inaccessible, try covering it with something that cats dislike, such as aluminum foil or sticky tape.
3. Make the spot uninviting. If you're thinking there's nothing on earth that could make a spot more uninviting than the lingering aroma of cat pee, you're thinking like a human. From a cat perspective, the smell of citronella, lemon, orange peel, vinegar, or mothballs is much worse.
4. If you can catch the cat approaching the spot, a quick shot with a water pistol or a spray bottle can be a deterrent. It's important to realize that this is NOT a matter of punishing the cat - it's trying to get the cat to associate the cat with something they don't like (being wet).