We have had our cat Halo (1 year old) for 8 months now. The first six months she used the litter box 100% of the time. In the last two months she has randomly stopped using the box for defecating. She always pees in the litter box and occasionaly will defecate in it, but about 90% of the time she will go on the floor. I can think of nothing that would explain this behavior and I have tried everything to attempt to change this behavior. She's been checked out and given a clean bill of health by our vet twice. I am getting extremely frustrated and would appreciate any ideas as to how to retrain her to use her litter box all of the time. Thanks!