You can retrain him to go outside, but I don't know how quickly. That's really up to him. I wouldn't leave the door open, but would let him out every hour, and praise him like crazy when he goes. Some people use a little bell on the door to train them to ring it when they have to go out. Maybe someone will come on and tell you how to train for that.
__________________  Susan, Piper ,Harley & Suiki |