I see nothing wrong w/ it. Like metioned before it is ussuallly because of some health problem that is overseen. Many dog sled racers take better care of their athletes than a person takes of himself. They have to take care of them well, after all if it weren't for the dogs the people would die out there.

Also if you have ever seen how carzy & excited a sled dog gets when you pick up his harness you truely know they LOVE doing it, therefore if they love it they must have no ill effects from it. I really wouldn't mind dieing doing somthing I love.