Michigan Compiled Laws, Chapter 433. Animals Running at Large § 433.15

(a) If the owner of the animal is known, return the animal to its owner, unless the owner refuses to make reparation as provided in section 3.  1

(b) If the owner of the animal is not known, give notice in a newspaper of general circulation in the area that the animal is in the custody or possession of the law enforcement agency. The notice shall include a description of the animal and the location where the animal was seized. If the animal is not claimed within 15 days after publication of the notice, the animal may be sold at public auction pursuant to section 6.  2