Abstract: This present invention provides regenerable antimicrobial animal fiber materials and methods for preparing the same. Such animal fiber materials are prepared using an aqueous finishing process to covalently attach a heterocyclic N-halamine to an animal fiber material. Once prepared, the finished animal fiber materials of the present invention have antibacterial activity against pathogenic microorganisms. Moreover, the antibacterial activity of such animal fiber materials can be regenerated by washing with a chlorine containing solution.