This how-to is aimed at owners of cats with sudden elimination problems. According to the ASPCA, "at least 10 percent of all cats develop an elimination problem." If your adult cat has a sudden elimination problem the most common possible causes, according to the ASPCA, include conflicts between cats (if you have more than 1), relocation of the litter box, or a cat's sudden aversion to the litter box. Or maybe the cat just doesn't like the type of litter itself.
Instructions
Buy a new litter box. Make sure that it's uncovered. Sometimes new is good for pets, too.
Change the litter more often.
Change the brand and/or type of litter. The reverse may also be true. If you've recently switched cat litter brands and/or types, consider that your cat may be reacting negatively to the switch.
Take your cat to a vet that you trust if you've taken all the proper precautions and feel that you've exhausted your options.