When I first got Duncan, we figured he was an outdoor dog too. He had a scar around his neck that the vet thinks may have been caused by a rope or wire tied around it. He was probably put in someone's back yard as a pup and left there. Thank God he escaped and they didn't bother looking for him! Anyway, he seemed to have a hard time adjusting to being indoors most of the time at first. He hung out by the front door a lot and looked out the windows constantly. He didn't seem to understand doorways or doors at all. The first few nights he would "flip out" when I shut off the lights. I think he was scared of the complete darkness inside so we slept with the lights on for a few days.If I stood up or moved, he would run to the door. I thought housebreaking him would be next to impossible but it wasn't and after about 2 weeks, he seemed to have adjusted to being an indoor house pet! So much so now that he doesn't like to be outside w/o me! I let him out to "use the facilities" and if I don't come out with him and stand on the porch, he leaps on the door until I do! It was fine in the summer but now it's like 10 degrees out...Not so much fun anymore!