I've always learned that some attacks can be avoided by how you react. If the dog is up ahead and seems menacing stay calm and in a firm and loud voice tell the dog to stop! go home and point out the opposite direction. It helps to make yourself look intimidating as best you can while doing it (if they are walking towards you... not charging you, I dont think you would have time to react). I put my small dogs in a football hold with the ass end facing the front (so the small dog can't see the other dog) That has saved my butt numerous times. I haven't been involved with any other scenario other than that, but that is what helped me.