I've heard this breed (Saanen) tend to live 13 to 15 years, but I don't know if there are any clues I can look for. (In the teeth? Horns?) I don't think he was very well taken care of before; someone just tied him up in our yard and left him. So that might make him look older than he is. His hair is thinning and he has a definite build up of musk, but he doesn't act beleaguered as far as I can tell. He's really a very sweet goat and I'd like to know how many years he has under his belt.