I have an ACD who's 1 year and 2 months old. He's an all around great dog. Like any dog, he has his minor behavioral annoyances, but we're working on those and he's doing better day by day. one bigger concern of mine is that for some reason he acts pretty aggressive when he's on a leash. Off leash, he's fine with everything and he loves other dogs an kids. When he has the leash on he nips at kids and acts like he wants to maul other dogs. As soon as the leash comes off, he's their buddy.
He still listens off leash and about 9 out of 10 times he comes when he's called. I can walk with him off leash at parks and the beach and he's good about staying by my side. however, i obviously need him to be on a leash in public places and around cars. When he acts up with the leash on, i will try to correct him by giving the leash a jerk and telling him "leave it". Then sometimes he will submit by laying down with his ears back and look up at me almost like hes sorry. other times he'll just keep going at it.
any suggestions??

