If you've been bit by a dog belonging to a neighbor or other person, then you may need to seek medical attention. If the dog wasn't tagged or you don't know which vaccines it's received, then you're in a position where you may have to have ongoing medical care for months to make sure you don't fall ill. Who is going to cover that cost? The owner of that animal should in most cases.
In New Hampshire, there have been several statutes released about animal attacks. For instance, the New Hampshire statutes consider a dog a menace if it's vicious, if it barks for sustained periods of time, if it chases cars or if it snaps, growls or bites people. When a dog bites a person and breaks the skin, an animal control officer has only 24 hours to tell the victim if the dog was vaccinated against rabies. If not, the victim is likely to need several injections to prevent the rabies infection, which can be deadly.
The owner of a dog that is not restrained or is left to be a nuisance may have the dog taken away and placed in custody. At that point, the court will determine what will happen to the animal. If a dog has become a threat to public safety twice within any 12-month period, then the owner must go to court over the attacks. Immediate proceedings at a district or municipal court are common, and the results may determine if the dog is taken away, put down or punished in some other form.
If you've been attacked, you have rights. If the owner of the dog is known, it's likely that you can take them to court over the costs you've accrued for your care. Speak with someone familiar with personal injury law if you need assistance.
Source: Animal Center, "Revised Statutes Annotated of the State of New Hampshire. Title XLV. Animals. Chapter 466. Dogs and Cats. Muzzing and Restraining Dogs" accessed Feb. 11, 2015