If I am carrying and a dog is charging me, I am not sure I would even call 911. The neighbors behind me have a couple bully breed dogs that bark and bite at the wooden fence when mowing. If they were to get out and look to be attacking me, I wouldn't think twice. I know, all dogs are not that way and it honestly could be the mower noise that is getting them like that. The dogs scare the crap out of me and they scared the crap out of my grandma when she lived there and I like dogs.
Don't blame the dogs. Blame the owners. I hate seeing "bully breed" tossed around. It's not the dogs fault.