Mass. Gen. Laws ch. 129 § 9
The agents of the Massachusetts Society for the Prevention of Cruelty to Animals and the agents of the Animal Rescue League of Boston may visit all places at which neat cattle, horses, mules, sheep, swine or other animals are delivered for transportation or are slaughtered, any pet shop where animals, birds, fish or reptiles are sold, or exhibited, or for sale, any guard dog business, any hearing dog business and any stable where horses are kept for hire or boarded for a fee, or any licensed kennel where animals are boarded for a fee or any animal dealer licensed with the United States Department of Agriculture, for the purpose of preventing violations of any law and of detecting and punishing the same and such agents shall have the power to prosecute any such violation coming to their notice. Records of inspection made under authority of this section shall be filed with the office of the division of animal health, within the department of agriculture no later than three months after such inspection. Any person who prevents, obstructs or interferes with any such agent in the performance of such duties shall be punished by a fine of not more than one hundred dollars or by imprisonment for not more than two months, or both.
Mass. Gen. Laws ch. 129, § 9