Mass. Gen. Laws ch. 129 § 39A
Every person engaged in the business of operating a pet shop, shall obtain a license therefor from the director, the fee for which shall be determined annually by the commissioner of administration under the provision of section three B of chapter seven for the filing thereof, and such license shall expire on December thirty-first following the date of issuance, unless sooner revoked. The director, subject to the approval of the governor, may make rules and regulations governing the issuance and revocation of such licenses and the conduct of the businesses so licensed and relative to the maintenance of premises, buildings and conveyances, the health of the birds, mammals or reptiles and the method and time of inspection and checking of said animals.
This section shall not apply to a publicly or privately owned zoological park, a publicly owned animal pound, an institution, as defined in section one of chapter forty-nine A, to persons selling, exchanging or otherwise transferring the offspring of their personally owned animals, or to horse or cattle auctions, or to a professional service dog organization accredited by Assistance Dogs International and headquartered in the Commonwealth of Massachusetts.
Mass. Gen. Laws ch. 129, § 129:39A