N.C. Gen. Stat. § 106-415

The cost of all tests, serums, vaccines and other medical supplies necessary for the enforcement of this Article and the protection of livestock against contagious and infectious diseases shall be paid for by the owner of said livestock and the cost shall constitute a lien against all said animals; provided that, the Commissioner of Agriculture, by and with the consent of the Board of Agriculture, is hereby authorized to determine reasonable charges and costs for such tests, serums, vaccines, and other medical supplies; provided further, that an animal which shows a reaction to a test for brucellosis shall be automatically "no-saled" and resold for immediate slaughter and the cost of the test paid by the original seller.