Jack update. As long as I keep him supplied with fresh tennis balls he is good. He is finally (at 1 - 1/2 years not chewing everything in site.) Jack- the sweetest most destructive pet in my life and oh how I love him :) Throughout my life I have always had dog{s} Love them each and every one. But never ever have I ever had a dog like this one. My precious pup can't stand not having something in his mouth (it's the retriever in him) and he is always ready to CHEW! He has chewed through chair...