I was very afraid of dogs when I was little, thanks to a neighbour having a badly trained German shepherd, another neighbour having some 4-5 small/medium-sized dogs that'd just bark and growl at (and occasionally bite) people, and another neighbour having a stereotypical Doberman with cropped ears and a docked tail that also liked to bark and growl at people when they got "too close"
(The doberman and at least one of the dogs I don't know the breed of had to be put down because they bit too many people. A shame since most of those things could probably have been avoided if the dogs had been properly trained. From what I remember the owners of those dogs were often away and the dogs were usually left outside.)
This fear once led to me "running for my life" from yet another neighbours Schipperke that occasionally liked to crawl under the fence of its enclosure >-> (That same neighbour also had two huskies that also sometimes "ran away" that I also "had to" run from on at least two occasions that I can remember.)
The funny thing is that that particular dog was smaller than a normal housecat and would probably have left me alone if I had told it to go home >-> Silly me...
I've gotten over that fear now, but I still feel a bit unsure around dogs I don't know..