When I get chews for our boys(bones and such), our oldest, Henry, will hide his or guard his until Oscar walks away from his own bone...then, Henry will try to take Oscar's away. Should I intervine? Oscar will try to get it back, but Henry will bare teeth. This never happens over food or snacks...just over chews. Any advice? I have tried to let them work it out and I have tried giving the chews back to each dog they belong too. I am confused on this one.