Dog to dog aggression while camping

Some people with dogs just do not have a clue. We have the most problems with little dogs. When we walk our Boxers I stopped counting the times a little dog comes from their site barking & growling at our Boxers. The Boxers look at them like they are crazy. The owner runs out scolding the little dog saying you would be lunch or one bite to them but it continues to happen. Our dogs are always on a leash but my fear is one of them would get bit by a little dog & they would decide to defend themselves or us. Never have even growled at anything but who know if they were attacked. :) me too for that matter.........

We always here they have never done that before, or we don't need to leash them because they are trained.