A loud voice and an upraised hand has perfect effect, without hurting your hand, or your dog.
Hurting your dog is counterproductive.
Always reward good behavior.
It is much more productive, and be judicious in correction.
I have a theory that most people are pack animals.
“Since this is such a new problem I suspect it may be caused by a medical condition possibly neurological.”
Yeah, okay, it’s a freakin doberman.
doofus! Ever owned one? Or been worshiped by a dobby?