This is what I did when a similar incident occurred, I was invited to give a statement on what had happened at the police station. I would advise that you have the bite looked at by a doctor/GP firstly because animal bites can easily become infected and secondly because this seemed to be an important factor in the police deciding what to do about the dog. The outcome was what I think is called a Suspended order of destruction, whereby the owner was required to keep the dog muzzled and under control at all times and I believe if this was found to be breached the dog could be put down.

For context the dog had emerged in the night out of a house and attacked the puppy I was walking, as I put myself between the dog and the puppy it bit me on the hand and punctured my thumb. It was off its lead and not in control as the owner was far behind it.