My dog i just got does well for the most part but sometimes if he sees another dog or cat or deer he will bark and pull toward them. I have tried staying there, treats methods, etc etc But nothing works so every time I will yank and pull him even to the point of picking up and dragging him by the harness. Even for up to 30 minutes to an hour or more. He wont stop pulling and screaming trying to get to the deer or cat even miles way from them It gets really brutal. He was previously an outside dog with the previous owner and food health wise was not taken good care of. He has scars and worn down teeth. I take good care of him and spoil him but the walks are seriously brutal. How do i know if this has damaged him and what to do? Im thinking a prong or shock collar.