My 5 year old male cat has been acting very strange for the past week or so. He has been spayed and has always had problems peeing and marking his territory, but now he's spraying everywhere - on the dining room furniture, stairs, couch, everything.. He has gotten extremely timid to the point of backing into the corner, growling and peeing when my husband or I walk into the room. I have 3 other cats, one of which picks on him some but not any more than he picks on the others. I am at my wits end.. he is ruining my house but I don't know what to do. I've tried shutting him in the bathroom with his own litter box, food and water, and he pees/sprays all over the counter and rugs. Any ideas why he has gone nuts all the sudden? I haven't moved furniture, gotten new animals, been on vacation, etc any time recently.