I* with GB on this one. I had a simular problem while living in Louisiana several years ago. Two bad dogs got out about the same time my son was getting off the school bus. He and another kid got bit. After taking him to the doctor I went up and knocked on the front door, I ask, "Has the dog had it's rabies shot?". The old gal that owned them told me it was none of my business. That was all it took, I called LEO and animal control and had the dogs locked up for 14 days under a vets care. They came back clean so the owner came to my house and insisted I pay the bills. I told her if she had answered my question, and told me the dogs had their shots it would have never happened, and there would be no bills, I didn't pay. That set her off, every day for the next three weeks she tried to sic the dogs on my kids. I had to take off work, go home, get my gun and meet the kids at the school bus. After a while, and some legal action things didn't get much better. Finally, I went to the folks and talked to the man and wife, I promised them that if my kid got bit again I was coming after them, no questions asked, and would kill the dogs in the process. Thing cooled off in a hurry.
Bottom line, an idiot can own a dog, if the dog is mean, you have a double threat. Do what ever you have to do to protect your family. If you can't shoot or find another way, a little anti-freeze on some dog food will make a good dog out of the worst one.