Michigan Compiled Laws, Chapter 287. Animal Industry § 287.351

Sec. 1. (1) If a dog bites a person, without provocation while the person is on public property, or lawfully on private property, including the property of the owner of the dog, the owner of the dog shall be liable for any damages suffered by the person bitten, regardless of the former viciousness of the dog or the owner's knowledge of such viciousness.

(2) A person is lawfully on the private property of the owner of the dog within the meaning of this act if the person is on the owner's property in the performance of any duty imposed upon him or her by the laws of this state or by the laws or postal regulations of the United States, or if the person is on the owner's property as an invitee or licensee of the person lawfully in possession of the property unless said person has gained lawful entry upon the premises for the purpose of an unlawful or criminal act.