Not sure how well this works, but a couple of people have told me to put a tablespoon of vineagar into a gallon of water. Use this mixture for the dogs drinking water. If she balks at the taste, you may want to start out with a teaspoon per gallon first, then build up to a Tbsp to acclimate the dog to the taste. We have two dogs, a shepard mix and a pomeranian/dachshund (sounds weird, but is gorgeous!) and don't seem to have "brown spot" problems for some strange reason, even though we don't use the vineagar. They are confined to the back yard, unless we have them on a leash, so they don't leave "problems" for others.

The lady that lives next to a Pit bull needs to call animal control - Pits are ILLEGAL in many areas, especially uncontrolled ones as this one obviously was. Good luck!!