Mass. Gen. Laws ch. 129 § 1
The following words as used in this chapter, unless the context otherwise requires, shall have the following meanings:
"Agents", employees of the division of animal health in the department of food and agriculture especially designated as agents by the director.
"Contagious disease", such disease as is recognized by the United States department of agriculture, animal health division, to be contagious or infectious.
"Director", director of animal health.
"Division", the division of animal health of the department of food and agriculture.
"Domestic animals", all animals including poultry that are kept or harbored as domesticated animals. Poultry as used in this section shall include chickens, roosters, capons, hens, turkeys, pigeons, guinea fowl, and ducks and geese other than wild species.
"Guard Dog Business", the business of furnishing, whether by lease or sale, dogs trained as guard dogs to protect life or property, or of training such guard dogs.
"Hearing dog", a dog that has completed a program of professional training to aid deaf and hearing impaired individuals whenever such dog is professionally trained by a person engaged in the hearing dog business to aid the deaf and actually being used for such purpose, or a dog owned by a person engaged in the hearing dog business within the commonwealth during the period such dog is being trained or bred for such purpose.
"Hearing dog business", the business of furnishing, whether by lease, sale or otherwise, dogs trained as hearing dogs, or of training such hearing dogs.
"Inspector", inspector of animals appointed under section fifteen or sixteen.
"Pet Shop", every place or premise where birds, mammals or reptiles are kept for the purpose of sale at either wholesale or retail, import, export, barter, exchange or gift.
Mass. Gen. Laws ch. 129, § 1