Dog Owners in Massachusetts are strictly liable when their dog bites. The only defense to this is that the dog was being teased, tormented or abused by the bitee.
Dog bite claims are generally covered under homeowner policies. If your dog bites someone, you should report it to your insurance company immediately. You will also have to produce vaccination records for your dog to prove that he or she has been vaccinated for rabies. If that is not the case, the bitee will have ro endure painful rabies shots which if they decide to bring a claim against you, will add to the pain and suffering claim.