What is that hand going to do to me?
Hitting a dog is a bad idea. Even one of those “Oh it didn’t hurt them,” swats is a bad idea. And here’s why. Dogs notice what things predict. If a hand has ever predicted getting grabbed, scruffed, swatted or worse, the dog learns that sometimes hands do unpleasant things to them. Puppies will learn this quickly, and even older dogs who were never routinely hit will learn quickly that some hands are not to be trusted should they ever be hit. The question for dogs will be to know which hands they need to be worried about. That’s where the danger lies, they may decide that being safe is better than being sorry, and will avoid or even bite any hand reaching for them.
Think about what many people do the first time they meet a dog. Think about what little kids do. They reach out their hand for the dog to get a sniff or give a pet, except that dogs are not mind readers and they don’t know their intentions. A dog who has been reprimanded or corrected by hands, or by something in a hand, may be more inclined to bite hands. Any trainer who suggests that someone uses their hands to do something scary or painful to a dog, whether it’s suppose to imitate another dog’s mouth (which is frankly a load of malarky) or to forcibly restrain or punish the dog, is behaving in a way that as a professional constitutes gross negligence. They should know better. They should know that the very last thing in the world we want is for a dog to have to worry about what a hand is going to do to them.