When I say dogs need dominance and structure I don't mean abuse your dog, do not torture your fucking dog. Just don't let your dog push you around, ever, you are in charge, always, and the dog must respect that. Reward respect, obedience, deference, and while I don't condone hitting dogs, pain is how dogs punish each other, wolves bite. The closest and safest thing to a bite is a mild shock, it feels like a nip. If people would just train their damn dogs using reward and discipline the dogs would be fucking perfect. A shock isn't supposed to last more than a second, it must be as quick as a nip or the dog will freak the fuck out and it will counterproductive.