The last time we had a routine vet appointment, someone called with a similar question. Here's what the receptionist said:
If a dog bites a family member or friend, it does not legally have to be reported if no charges will be pressed. The dog must be up-to-date on all shots, including rabies vaccine.
If you are bitten by (or your dog bites) someone who will press charges, it must be reported and the vet must provide proof of immunizations and current rabies protection.
If you (or a family member) are bitten, tell the MD or ER staff what happened and which dog did it, if you know. If you don't know the dog, give a description of it to police.
Our two dogs are always current on ALL shots and always have their licenses, rabies tags, and ID tags attached to their collars. They are also microchipped.
As friendly and loving and goofy as our two dogs are, we prefer that people that aren't regular visitors don't pet them. We think of them as our big, silly, loving, furry kids, but they are DOGS, after all.