Section 58A. Any veterinarian duly registered under the provisions of section fifty-five, or who is a resident of another state or in the District of Columbia and duly registered therein who, in good faith, as a volunteer and without fee, renders emergency care or treatment to an animal other than in the ordinary course of his practice shall not be liable in a suit for damages as a result of his acts or omissions which may occur during such emergency care or treatment, nor shall he be liable to any animal hospital for its expenses if under such emergency conditions he orders an animal hospitalized or causes his admission to such hospital.