3 Pa. C.S. § 459-501. Killing dogs; dogs as nuisances
(a) Legal to kill certain dogs.--Any person may kill any dog which he sees in the act of pursuing or wounding or killing any domestic animal, wounding or killing other dogs, cats or
household pets, or pursuing, wounding or attacking human beings, whether or not such a dog bears the license tag required by the provisions of this act. There shall be no liability on such persons in damages or otherwise for such killing.