I tried using greenies, but he doesn't like them all that much. He just gives it a few chews and just leaves it alone.
Since he doesn't like those, try going with what Pat said and get him some raw bones (get one for your other dog too [Vivi?? Did I remember that name right?), they tend to get possesive if there is only one bone around and two dogs). Yeah, just go to the meat dept. of the grocery store and get some marrow bones. Dogs love them, the chewing cleans their teeth and makes their breath better, and the marrow is really good for them. Good luck!