Originally Posted by surgeonstone

The trouble with his approach is that the dog has won and its behavior has been reinforced to the chagrin of he next rider. You are thinking yeah, what a stud, I left that guy in the dust. The dog meanwhile sees it has successfully chased off another intruder to masters territory. Better to simply acknowledge in a friendly manner and keep the same pace going. If the aggression continues to escalate then deal with it from there. Remember they are pack animal and if they come at you in twos or threes be wary of what is happening behind you.