I dont walk Happy on leash, even crossing streets.. and she is dog fear aggressive, but I also dont allow her to go after another dog, one comes into view and I am kneeling off the side holding happys scruff and muzzle. also on a busy street Happy is to stay in a perfect heel at all times, on quite streets I loosen up but Happy knows the way it works. thing about Happy though is that she is worse on leash when it comes to her fear agression, because she feels trapped so attacks far more readily and agressivly. then again Happy is also VERY well behaved, and she wont go after something no matter how intresting it looks without my permission. but I dont know how this guys dog is, could be like Happys mom, always allowed offleash, but NEVER under control while she is off(meanwhile, while her dog is running off and noone can find her she is mad at me for Happy being off leash under complete control now THAT drives me up the wall!)