My mother is afraid of dogs too. She has been terrified of them since she was little and a large poodle bit her across the face.
There was one amusing little incident that happened in FL several years ago. She and I were browsing through pawn shops looking for a VCR. We go walking into one shop and she approached the glass counter and starts glancing through it. She sees the reflection of someone approach from the other side of the counter. She looks up and is face-to-face with a HUGE great dane (belonging to the owner, no doubt) that was standing on its back legs with its front legs propped on the counter. My mother moon-walks out of the store and never went back.