Hello; I have a 10 year old Abby that is driving me nuts. This is a one cat household. We have three litter boxes for this cat and they are kept clean and scooped every day with fresh litter added. We have used the same litter since we got Callie as a kitten and she is not declawed. After all that, here is the problem. Callie has started to poop on the cement floor in the cellar. She always used the cellar litter box for defecation until recently. The bizarre aspect of this whole thing is that she still uses the same litter box to urinate in. At first, I thought she might have arthritis that might hamper her getting into it (it is uncovered). She apparently has no problem getting into the thing which is plenty big to accommodate her. I have heard of cats suddenly stop using a litterbox but never to stop using it for one function only???? Help!