If a person does not appear to claim an animal impounded under section 2 within 7 days after the date of impounding, the director shall sell the animal by auction in the county where it is impounded. The director shall first advertise the sale by posting a notice thereof in 3 conspicuous places in the county not less than 5 days before the sale and by serving a copy of the notice on the owner of the animal if the owner is known and resides in the county.