Thank you for your reply.
I understand where you are coming from, being hesitant to give out advice, but I can assure you I have no intention of going out and picking fights with innocent dogs! I understand that avoidance is the most important aspect, which is why I wondered if people had tips for de-escalating a confrontation with a dog.
I'm a peaceful, law-abiding guy but I just want to have a reasonable level of preparation for a worst case scenario. It struck me the other day (as I was walking through a dodgy neighbourhood) that if a dangerous dog were to run at me I'd have absolutely no idea how to react.
I am sure dog attacks are rare, but they do happen and I think it is sensible to have some sort of basic preparation for it. I was once walking along a public countryside path near a farm-house with a friend and his dad and a German shepherd ran out, completely silent and leapt and bit my friends dad on the arm. I think the attack was half-hearted, because he retreated pretty quickly, but he made a sizable gash on his forearm. So they do happen, and I'd like to have a basic strategy for dealing with them.