Originally composed of twelve laboratories when implemented in 2002, the National Animal Health Laboratory Network (NAHLN) has grown to include 60 State and university laboratories. These laboratories are distributed throughout the United States, and are capable of testing large numbers of samples for specific disease agents. The NAHLN supports U.S. animal agriculture by developing and increasing the capabilities and capacities of a national veterinary diagnostic laboratory network to support early detection, rapid response, and appropriate recovery from high-consequence animal diseases. It is a nationally coordinated network and partnership of Federal, State, and university-associated animal health laboratories. NAHLN veterinary diagnostic laboratories provide animal health diagnostic testing to detect biological threats to the nation’s food animals, thus protecting animal health, public health, and the nation's food supply. They provide the capability to diagnose both endemic and foreign high-consequence livestock pathogens in animals and environmental samples and are likely to be the first-line laboratories for recognition of an intentionally or accidentally introduced agent in animals. The National Veterinary Services Laboratories (NVSL) continue to serve as the nation’s reference laboratories for both the NAHLN and USDA.