"If a dog threatens you, call him to you. He has no reason to obey you." (Henry Thoreau)   I have used that method successfully many times.

As for what Gypsy went through, I'm not sure what I'd do. Maybe handing both little dogs to my companion would free me to take action against the marauding dogs. The dog owners were reprehensible but arguing with them could be dangerous, if only because their dogs could pick up on my anger against them.