My cat has stopped using her litter box. I had two cats, one got out and we have not found it yet. The other one has stopped using her litter box -- she pees and dirties any place she decides to -- her favorite peeing spot is a sling chair which is washable, her dirty spot is in the bathroom, the rug or the tub or the laundry room if the door is left open. I don't know why she is doing this. Should I move the litter box and see if she will start using it again?