I adopted a 2.5-yr old Australian Cattle Dog, and he is very sweet natured and well-behaved, one of the best dogs I've ever had. Except for occasionally on his leash. He has a bad habit of turning around, biting his leash, and pulling and dragging backwards very aggressively. It hurts, and his favorite place to do it is when crossing a busy street where it's very dangerous. I've tried a couple of different discipline options for this, ranging from vocal scolding to (when it gets really bad) putting him on his back in the submissive position until he calms down. A friend of mine who trains agility dogs also suggested putting the leash in his mouth after he does it and quickly pushing backwards, hurting his mouth. Nothing has really worked so far, because he just keeps doing it. It's not the collar or harness I use, because I've tried almost every kind (except a pronged-choke collar, I don't know if I'm ready to go there yet). Lately, it's been bad enough that I'm drawing negative attention from bystanders. I've even gotten some really nasty comments and looks, and while I know I'm not hurting him by placing him on his back, it's still very upsetting. I'm looking for a way to discipline him for this behavior without drawing a negative crowd. It's so weird, because it's really like a switch and he's incredibly well-behaved and sweet all of the rest of the time. Can anyone help me?