Save a starving pit bull with mange!

Our neighbor has been mistreating and abusing dogs for FOUR years and NOTHING has been done. I have calling the humane society, etc., but NOTHING has been done. Promises have been broken by them. The owner continuously breeds his dogs, starves them and they get NO medical care.
They are all pit bulls. It started with three. Ended with one.
ONE dog was FINALLY taken away after THREE years. Two of the dogs ran away and have never been seen since.
The remaining one has severe mange and is starving. He eats our fish out the pond and we feed him sometimes, but we don't want to risk the mange getting to my two poodles.
This all started with two dogs- a male and a female. The male was aggressive while the female pit bull was as sweet as could be. They had puppies. The mother dog could not get enough nutrition and her milk started to dry up. We took in the poor puppies and fed them. One died and the others were given away at 5 weeks old. One remained.
The one who was kept by the 'breeder' was treated the same way but chained up. Soon the other dogs were chained too, and the mother dog had another litter of puppies. We are not sure of how many litters she had before we noticed them or paid attention.
She had around one or two more litters after that. She ran away as soon as she got loose with another dog.
We called animal control way before she had the second litter of puppies.
No one ever showed up.
Three years later, they took the remaining dog away. Long before that tho, he had his own litter of puppies with another female. The other female was given away.
The last puppy, which was ignored by animal control, now has severe mange has noted above and is starving.