My German shep learned to stop chewing shoes this way. Nothing we did could get him to stop - it was intolerable. One weekend we went to visit a friend of ours

My German shep learned to stop chewing shoes this way. Nothing we did could get him to stop - it was intolerable. One weekend we went to visit a friend of ours that owned an older shep (actually a cousin of our shep's, from the same breeder.) My dog went for one of the owner's shoes. The older dog gave him a nip on the muzzle, and that was the end of it. He never again, even after we came home, went after a shoe.