I have a 7 year old Maine Coone cat, she is not in best of health and now has limited use of rear legs. I got a litter tray so she could wee and poo in that to save her going out through the cat flap, the other cats use it (I have three) but she just pisses on the hallway floor. So bloody infuriating. I have no clue what to do! I clean up, spray anti pissing stuff on the floor but she goes back and does it there every day! I am losing patience with it as I do not know how to conquer it or get her to either use the cat flap (which she always used to) or pee in the litter tray!