My previous dog, a shephard mix literally out of a pack of wild dogs in New Haven, I adopted when he was probably a year old in 1980. He was a great dog to hike with, would disappear for periods of time and reappear almost instantly with the slightest whistle or hand clap. My current dog, I always needed to keep him close or on a leash in the woods - not quite as bright as the other one was.