I have a 1 year old pitbull over 65lbs and although he's great in the house once he's outside he wants to see every person on the street when out for walks. Any animals from tiny birds to ground hogs he will pull a great deal to pursue what's caught his interest. It's almost impossible to get his attention to be on me because he's ALWAYS alert when he's outside and focused on what he could see next. I've purchased a prong collar for him and it's sort of eased his pulling except when he see's someone he knows or another dog he will pull with all his might completely ignoring the fact that the collar is choking him. He's ruined almost every collar we've got which includes snapping the link that attaches the leash to his leather collar. The links on his prong collar are all slowly bending and becoming easy to come off. I've also tried a harnness which he's chewed through.