In New Jersey, the owner of the dog (actually his homeowner’s insurance company) is responsible if the dog bites someone. It is known as “strict liability”. That means that no proof is needed that the dog was dangerous, or that it had bitten other people in the past. If the dog bites you, the homeowners insurance company is responsible for the claim.*
Many people who have been attacked by dogs and seriously injured are reluctant to make a claim, saying, “I don’t want to sue my neighbor” or “I don’t want to sue my friend.” This is understandable. However, the claim is actually against the homeowners insurance company which insures the home where the dog resides. Most of the time, a trained and experienced attorney can get you a reasonable settlement without any lawsuit at all. It is handled as an insurance claim.
*The law would be different if you were illegally on the premises of the dog owner, or if you deliberately provoked the dog into biting you.