Follow a master plan First, determine which areas are soiled. Then clean those areas completely. As long as your pet can smell his personal scent, he'll continue to return to the "accident zone." And even if you can't smell traces of urine, your pet can, so you must be sure to remove (neutralize) that odor—this means following all the recommended cleaning steps. If you fail to completely clean the area, your re-training efforts will be useless. Once it's clean, make the accident zone unattractive and/or unavailable to your pet and the appropriate "bathroom" area attractive. Have your pet checked out by a veterinarian to rule out medical causes for the accident. When you are certain your pet is healthy, use positive reinforcement to re-train your cat or dog (or train your kitten or puppy) to eliminate in the proper place. There may have been a reason why your pet chose the wrong place to eliminate.
This may seem obvious, but in some cases the spot will have dried invisibly and be hard to locate. Follow these steps: