I have been bitten only once....many years ago. Strapped in (not clipped) on a long climb. Got to a hairpin turn and a German Sheperd came running down the hill, and clamped unto my leg. Fell over, and managed to undo the straps. Then I kept the bike between him and me. Shortly after this, a mother and child came walking down the road. I can only think that the dog was protecting his family. Mom was none too pleased about the holes in my new jeans. In the years since, I have out sprinted a few dogs (intervals are good), and have used the water bottle on one occasion. The latter worked wonderfully.