Mass. Gen. Laws ch. 272, § 80I – Leasing or renting dogs; penalties

(a) As used in this section, the following words shall have the following meanings unless the context clearly requires otherwise:—
''Assistance and service dog'', a canine specifically trained to help persons with disabilities or a canine trained to help a person with a disability in life; provided, however, that ''assistance and service dog'' shall also include a canine trained for search and rescue and a medical response dog.
''Canine foster care'', an organization that places canines in a temporary home while awaiting pet adoption.
''Earth dog'', a canine breed used as a hunting dog to track game above and below ground.
''Farm dog'', a canine that works on a farm to assist humans or other animals.
''Pet adoption'', the permanent ownership of and responsibility for a pet that a previous owner has abandoned or otherwise abdicated its responsibility.
''Renting and leasing'', the practice of renting a dog for a fee or a cost which will knowingly result in a temporary possession of the animal by another party.
''Therapy dog'', a canine that is used under the ownership and care of its handler that visits people for educational, medical or mental purposes.
(b) No person shall engage in the business of leasing or renting a dog. A dog held for such leasing or renting may be seized or impounded by an organization or agent thereof that is authorized to seize or impound animals under the General Laws. A violation of this section shall be punished by a fine of not less than $100 for the first violation, not less than $500 for the second violation and $1,000 for subsequent violations. Fines may be levied on both the business that is leasing a dog and the person that has entered into a rental agreement. Nothing in this section shall prohibit service animal businesses or organizations, pet adoption and foster care services, and working animals for the following purposes including, but not limited to: service animal businesses or organizations, pet adoption and foster care services, farming and agriculture, working dog activities, dogs working in entertainment and shows which are authorized to do so under the General Laws, dogs participating in performance sports or activities including, but not limited to, sporting, hunting, earth dog and racing dog activities and people engaged in breeding, training and showing dog, and dogs used for medical or scientific purposes so long as such use is lawful. This section shall not prohibit a pet store, kennel, pet adoption service or other entity authorized to sell pets under the General Laws for a fee or a cost from taking back a pet that it may have sold if the owner is unable to keep or handle that pet.