I have a 2-yr-old Borador (Border Collie/Lab mix) Newton who is an eager learner as long as our sessions are fairly short and fast moving; anyway, with the "Take It" exercise he's never been inclined to hold anything in his mouth for any length of time unless it's a ball or toy being used in a game of fetch or tug. When I try to get him to pick up a toy that I'm not waving around inciting a game he picks it up in his mouth for a split second, gives his head a nod and flips it out of his mouth in my general direction. Can't get him to maintain that hold in order to progress to carrying something for me or going to retrieve something. (The "retriever" part of his Laborador genes seems to have gotten lost somehow! LOL) What can I do to encourage him to take up and hold an object in his mouth for a period of time? Thanks!