In my 20 year past career, I have no idea how many dog attacks I investigated. Most of these attacks however, were from pit bulls, and chows, or mixes of the two, but I will say not always. People that own the dogs, ALWAYS SAY, the dog has always been gentle and wouldn't hurt a flea.
What 99.9% of the dog owners just don't get, is that these dogs don't "usually" bite THEM, because they (the owners) are considered by the dog to be the alpha male, and or, female of the pack. Dogs and people do not think alike. We see the dog as a "family member", and the dog sees us as "pack members", and an obstacle to the top of the "pecking order" of that pack.
This past week in Arlington, Fl, a baby boy just a few weeks old was laying on the bed beside it's mother. The family pet "pit bull" jumped up on the bed, grabbed the baby by the head, and jumped off the bed, mauling and killing the baby. The owners "once again" claimed the gentleness of the dog. I suppose they can have that engraved on their infant son's tombstone. Killed by the "gentle family pet pit bull".
Powderman, I admire your restraint and calmness in the situation, as I have been confronted "many times" in my 20 year career with aggressive dogs, sometimes with their owners assuring me, "he won't bite". I did then, and do now, give the dog one chance MAYBE to retreat, and behave himself, then I turn the lights out with no apologies. Little dogs have many natural enemies, even if "in their own minds" (instinct), and big dogs (especially certain breeds) mark their territory, and sometimes defend it "in their own minds" (instinct).
My K-9 patrol dogs were all German Shepherd, and were dangerous to anyone other than the handler. Yes, I allowed them to interact with my family, BUT! I kept a constant vigil. They were what they were, and I had made them such, as I trained patrol dogs from pups, not venders. A good sized healthy Shepherd has about a 750 psi bite. Something to think about yes? These dogs, like many large breeds are territorial. That's why we used them. To protect the territory.