agility is very good for aging dogs, as it gives them a chance to keep both their minds and their bodies active. You may, however, want to consider a glucosomine supplement, just in case. You have to be careful with those aging joints and glucosomine is a great supplement. Those little terriors are really active, but they can also be pretty stoeic when they hurt. Just start off slow and build him up to the height levels for his size. Also, make sure he gets a really nice warm-up before every class.

I started my aussie mix in agility when he was about 7 years old and he loved it more then anything in the world (aside from his family )

Good luck, have fun, and welcome to the site