My girl, Precious is a Main Coon, 12 years old and weighs 19 pds, and she has been having a problem with defacating outside the box..... She would defacate on my Persian rug in the living room, so I took her to the vet. It seems that she has arthritis in her lower spine, and has what is called mega colon. So I moved another litter box into the living room and put heavy painters plastic over my Persian rug. She was using the livingroom box for a good long time, so I took the plastic off the rug, and woke up 2 weeks later to find feces on the Persian rug. So I covered it back up....Now when I wake up in the morning I find she has defacated on the painters plastic and just ouside her box. What should I do now ????? ( This is only defacation, she always urinates in the box)