As defined by the Legal Information Institute at Cornell University, the one bite rule
Says that the owner of a domesticated animal (e.g., a dog) will be held strictly liable for injuries caused by the animal only if the owner knew or should have known about the animal’s dangerous or vicious propensities, which have been manifested in the past. The burden of proof is on the injured party to show that the animal owner possessed this knowledge. The “one-bite” rule originated in common law and has been rejected or modified by most states, either by statute or by case law, with regard to dogs.
North Carolina is one of the minority of states that continues recognizing this principle. However, section 67.4-1 of the state code pretty much invalidates the one bite rule by making a dog owner completely financially responsible for any attack that results in a severe injury. That statute also defines a severe injury from a dog bite as one “that results in broken bones or disfiguring lacerations or required cosmetic surgery or hospitalization.”
In practical terms, any dog bite that requires stitches or more should provide grounds for an insurance claim in North Carolina.