I don't know which is doing it, the dog or the cat, but one of them has started urinating in the same spot by the back door. The dog spends lots of time outside and the cat has a litterbox. This just started. Both are adults and both hang out in that particular spot. What can I do or use to eliminate the pheromonal smell that gets left behind even after the area has been cleaned and disinfected? I can't think of another reason the same spot keeps getting used. Only one other possibility comes to mind. I used to keep a folded up cheap polar fleece blanket by the door to keep the winter drafts out and the cat snoozed there quite a bit. The blanket got washed and put up a week or so ago. Could this be a protest about the blanket being moved?