18 Pa.C.S. § 5540: Hours of labor of animals.

(a) Offense defined.--A person commits a summary offense if the person leads, drives, rides or works or causes or permits another person to lead, drive, ride or work a horse, mule, ox or other animal, whether belonging to the person or in the person's possession or control, for more than 15 hours in a 24-hour period or more than 90 hours in one week.

(b) Construction.--Nothing in this section shall be construed to warrant a person leading, driving, riding or walking an animal for a period less than 15 hours, when doing so shall in any way violate the laws against cruelty to animals.