What to Do When Your Cat Stops Using the Litter Pan

1. Keep the litter pan clean.  A cat or kitten will not use a litter pan that is not cleaned frequently. 
2. Scoop the solids out at least once a day, if not twice a day.
3. Replace the litter entirely once a week.
4. When you replace the litter, wash the litter pan with dishwashing liquid and little bleach added.
5. Try changing the brand or the type of litter in the pan. 
6. Once your kitten has used another area outside of the pan, it is essential to eliminate his odor from these locations.  Use a high-quality odor neutralize meant for this purpose, not detergent, perfurme, soap and water, and definitely not household ammonia.  Ammonia will actually attract the cat to the spot.
7. Give your cat added affection, play, exercise, and food treats.
8. If you catch your kitten in the act of eliminating outside the litter pan, say very loudly the word "NO," and carry him off to the litter pan.  give him a food reward if he uses the pan correctly.
9. To avoid use of the bathtub as a toilet, fill it with about two inches of water until the problem stops.
10. Confine the cat to one room until the problem comes to an end.
11. In a multicat household, be sure to have more than one litter pan.
12. Have your cat surgically altered.
13. To prevent your kitten from returning to the same spot he has been soiling, cover it with a large piece of furniture so he cannot re-mark it, which is what cats and dogs are compelled to do.
14. If you see him going near the same location, scoop him up in your arms and take him to his litter pan.
15. Give him a food reward if he does it correctly.
16. If your cat backs up against a wall, take him to the litter pan.
17. Sometimes a litter pan problem can be solved by simply reminding him how to use it.  Repeat the procedure many times and use a food reward and verbal praise each time you do.