Whenever an incorporated society for the prevention of cruelty to animals shall keep and maintain for 7 consecutive days an unlicensed dog whose owner is unknown, full title to the unlicensed dog shall pass to the society at the end of the 7-day period, unless the owner of the dog shall, before the expiration of the period, cause the dog to be licensed and shall pay the society a necessary and reasonable fee per day for each day the dog has been kept and maintained by the society, plus any necessary veterinary fees incurred by the society for the benefit of the dog.