iv seen people kicking the shit out of dogs when they did in my eyes nothing wrong and I felt like kicking the compete shit out of them if I were there dogs id bite there face of.
I keep a firm but fair hand on my lurches the occasional slap if required but a stamp of the foot and loud deep voice is usually enough to keep them right the more praise they get the better they trust u and a better they work for u.
the only time I ever went really hard on a pup was when a 7 mouth old pup went for a flock of sheep he never did it again.