With any dog, it's a good idea to keep their training up to date even as they get older. My youngest dogs are turning 6 this year and are happy and healthy. My Eldest dog is turning 12 - she is completely blind, has arthritis and has a few old age problems. The basic control training that we've kept up with my dogs means that we can all live in harmony a bit easier. If the blind dog is about to walk into something - we simply tell her to 'wait' and we direct her physically. If one of the younger dogs is in her way we can call them out of the way. It really does help especially in a multi-dog household.