I am not afraid of dogs per se, but I am cautious around strange dogs (my SIL has a maltese who is adorable and friendly. I’m not wary of her). Here are two stories of why I am wary:
1) This happened a long time ago in Monsey. There were four women walking on West Maple Ave down a stretch that has a farm and thats it. The owner had a vicious dog that was chained up. It was really a scary dog that growled and barked as everyone passed. The owner is an anti-semite who I think enjoyed seeing Jews walk by on Shabbos, terrified of the dog. So anyway, these four women were walking and the dog somehow got loose. They froze, petrified, as the dog was running towards them to attack. One of the women had the sense to say the pasuk against dogs and as the dog was running across the street, a car hit the dog and killed it. Keep in mind, this is a fairly quiet street on Shabbos and not many cars come. It was a pure chesed of Hashem that they survived.
2) My coworkers daughter has a big pit bull from the pound. Her brother came over to visit with his dog (I think a lab). As he enters the house, the pit bull sees a tall, threating looking man and lunged at him. He tore the guy’s lip/mouth and he had to have over 100 stitches. Turned out the pit bull was abused by its former owners, who were tall imposing men. He saw this poor, Tall guy and attacked within seconds.
I walk near dogs. I dont cross the street. My mother is afraid, but taught us just to walk on by. I have a sister who is terrified and will move to another continent to avoid a dog. I feel bad for her because she cannot function normally near a dog.