My Buck is very well mannered and not dog or people aggressive at all and I dont need a leash, but use one just to be safe. In fact when a dog comes running up to us, he will try and get away from it, side stepping carefully as not to trip me.
I also raise sheep and when I have to go into the pen with a very agressive ram, I carry a bottle of apple cider vinagar and spray them lightly around the face area. This stops the rams from charging me instantly, and it only takes once or twice to work. Apple cider vinagar is completely safe and will not hurt the animal at all. I started using this when a ram that got out surprised attacked my daughter. And this has never happened again.
So, I thought of taking my spray bottle with me when I walk Buck, and now the dogs that used to chase us just stand there and make a small timid bark, but never come running or close to us. I had one of the owner's come yelling at me when he saw me spraying his dog. I asked him to weigh the odds there, a little spray is better than losing his dog to animal control or a car, because if his dogs was to bite my dog or myself, I would press charges, and he shut right up. If you think about it that way or another dog killing your dog, you'll have no problems with spraying a little "safeguard!"