One of the most annoying, and certainly one of the most disconcerting problems of road cycling, is getting chased by a dog—you just never know how aggressive they will get. The best way to handle dogs is to first try and ignore the animal and hope that as you pedal away, they will stop. You can also try a firm, “NO”, if the dog doesn't stop.
* Try keeping an old sock with a knot in it handy. If you come across an unusually persistent dog, you can throw the sock and chances are the dog will chase after it, allowing you to ride away. If you do have to stop, place your bicycle between you and the dog.