7 U.S.C. § 2134

No dealer or exhibitor shall sell or offer to sell or transport or offer for transportation, in commerce, to any research facility or for exhibition or for use as a pet any animal, or buy, sell, offer to buy or sell, transport or offer for transportation, in commerce, to or from another dealer or exhibitor under this chapter any animals, unless and until such dealer or exhibitor shall have obtained a license from the Secretary and such license shall not have been suspended or revoked.