Mass. Gen. Laws ch. 140 § 152
Each police officer, constable or animal control officer to whom such warrant is issued shall make returns, on or before October first, on or before January first, and on or before April first, in each year, and at the expiration of his term of office, to the mayor or chairman of the board of selectmen issuing the same, and shall state in said returns the number of dogs and cats which he has caught, confined or killed, or made available for adoption, the names of the owners or keepers thereof and whether all unlicensed dogs in his town have been caught, confined or killed, or adopted, and the names of persons against whom complaints have been made under the provisions of this chapter relating to animals, and whether complaints have been entered against all of the persons who have failed to comply therewith since the previous report.
Mass. Gen. Laws ch. 140, § 152