I was on a group ride a few years ago thru some really nice back country roads. One guy in our group, larger guy, about 6'3" and pusing 300lbs. and a former pastor, decided to help out when a dog started running towards us. He gets close to the right side of the road so there's noone else between him and the dog and in a loud, booming voice shouts, "NO!". At that very instant the dog stopped and sat down as if it reached the end of an invisible leash.

I've used the water bottle method (squirt, not thrown) on a pair of dogs that attacked my riding partner. They came out at her one day and caused her to wreck. Unfortunately, even after talking to the owners they will not tie the dogs up. They've come out at us atleast 3 times now.