Article 1 - How To Keep Your Dog Safe While Walking Him
How to keep your dog safe while walking him:
You can only control YOUR dog and where you walk. You keep your dog safe by teaching him to have consistent reliable recall, that's the come command, and by keeping your dog under your control, preferably on a leash.
If you walk your dog on a route that you KNOW has a dog, off leash that is aggressive? Change your walking route. Do not take chances with your dog. If the local dog park has aggressive dogs or inattentive dog owners? Figure out when they are not there and go then.
Carry a cane or a walking stick, not to hit other dogs with, but to push them aside or to use as a barrier for an aggressive dog to bite at rather than your arm or let. As a last resort you can indeed use it to defend not your dog, but yourself. Do NOT try to put any part of your flesh between battling dogs. Use your cane or walking stick to do that. It seems like instinct to do so. You will only get badly hurt, possibly even by your own dog.