Most of the dogs that I've encountered have been easily stopped by yelling at them or blowing my whistle. There are two that looked pretty vicious until I blew the whistle at them and now one just sulks when I ride by the other will look at me and shake it's ears and go back home.

That said, I have one problem dog (a great dane) that only gets more aggressive no matter what I do. The whistle has him lunge closer and he ignores yelling. I'm thinking it is just a matter of time before it bites. I have not figured out what to do about this one yet, but I suspect it will not end well for one or both of us.

I did have trouble with another dog last Saturday. A very friendly lab that followed me 2 1/2 miles home (much to the displeasure of my dogs). Since I live in a hilly area and labs can do better than 30mpg, I could not outrun it. I ended up driving it back home and finding out the owners were not around to let them know of the trouble it was getting into.