I point straight at the dogs and yell a loud "GO HOME". And hit the gas on my riding a bit.
So far no problems, although I did have a person say their dog was a "Good Dog" right before it grabbed for a piece of my handlebars. Then, one dog near Portland that just kept coming. Never saw it again though.
I have to think homeowners hear my ROAR... and those that are conscientious keep a tighter reign on their dogs.
I did have a dog at a mandatory turn-around. When I said "GO HOME", the dog just went and sat down at the corner of it's property.... "This is HOME". As long as it wasn't chasing me, that was all I needed.