I ride about 3 miles out of my way at times to avoid a farm where the farmer seems to train his dogs to be aggressive. When I noticed this problem on early bike rides, I mentioned it to a sheriffs policeman (equivalent of a gendarme) and he told me that such behavior was not unlawful in the county, as dogs do not need to be tied up outside of city limits. Avoidance adds miles, and is the best alternative. I also have two or three dogs that live at the house of a lady I know from work. They are also in the country. But that situation involves getting tiny graham crackers. They chase me, get the little crackers, go home.