My dog is becoming aggressive
I will start using this (pictured below) collar from now on which has prongs pointing inwards so it hurts him when he pulls. He does not act like this at the dog park towards strangers. Any suggestions? Put a muzzle on him as an indicator that he is no friendly dog? Zap him every time he acts hostilely against random people? Or have him trained by a pro? What can I do as a responsible dog owner?
He used to do this once in a blue moon which is fine. But now it's like 50-50. Or at least I feel that way. He used to behave most of the time and not do anything. But now I do not feel that way anymore.