My family had an awesome dog once. A labrador. It was the most disciplined and loyal dog I've ever seen. Even though it never had any training. In the summer there would always be a door open, and it just went out, whenever it had to go out. At that time we lived in the very last line of houses in the town, so it could just run around on the surrounding fields. It would sometimes be away for hours, but as soon as you called him or whistled he would be there in a second.