Cats are consistent animals, they can get upset at you if you change something they do everyday, like food, or even where the water bowl is. but it\’s not that likely. How often do you change the litter box? Is it in an ideal spot for your cat? It is covered? Is it in a cluttered area? Has it moved spots recently? Cats are also extremely clean animals and will start to act out if the litter box isn\’t being cleaned enough or the entire litter isn\’t being replaced frequently and just being added to.
The box also requires cleaning every once in a while. You may not smell it, but your cats do, and if you CAN smell it, what makes you think your cats want to? Their sense of smell is way stronger than yours. Have you recently gotten any new furniture? Moved furniture around? Cats don\’t like when this happens, and some will even poop on the carpet to let you know (consistency). It could also be a marking thing. If you\’ve gotten any new furniture or have moved it, the cat may want to be pooping on it as a territorial and scent thing.
If it\’s already been several weeks since the food has been changed then you should probably take it to the vet, it could be a very serious problem. Cats are also very good at hiding pain.
There\’s your first problem. Cats are very clean by nature — in addition to regularly cleaning out the entire thing, you should be scooping at least every day. I admit I am really bad about this myself.
The general rule is that most litterbox problems are psychological–they either don\’t like the condition of the litterbox or they don\’t like the location (too loud, too dark, too busy, smells odd, etc). Try scooping every day for starters. If there is still a problem, find a new location for the litterbox (make sure he knows where it is) and see if that helps. The tip about not using strong-scented cleaners when you\’re cleaning it is a good idea, too, as well as the possibility that he might not like the enclosed feeling with the lid.
I\’d be willing to bet that it\’s a psychological issue that he has with the litterbox, and a few modifications in its cleanliness and possibly location will solve it. I went through this about 2 years ago with one of mine–she decided I wasn\’t scooping it often enough for her and started pooping right in front of it. I started scooping every day and it eliminated (hah) the problem.