Mich. Comp. Laws § 750.55
Any society incorporated in this state for the purpose of preventing cruelty to animals may designate 1 or more persons in each county of the state to discover and prosecute all cases of the violation of the provisions of this chapter; and the sheriff of such county may appoint each person so designated a deputy sheriff, provided such person shall be of good moral character, and each person so appointed by the sheriff shall possess all the powers of a sheriff of the county in the enforcement of the provisions of this chapter. The sheriff shall not be responsible for any of the acts of such person or persons, but the society, if incorporated, and if not, then the officers and members of the society, on the request of which such person was appointed, shall be liable in the degree of a principal for the acts of an agent.
MCL 750.55