Wis. Stat. § 256.155: First aid to domestic animals.

(1) Definition. In this section, “domestic animal” has the meaning given in s. 895.484 (1) (a).

(2) Rendering first aid allowed. An emergency medical services practitioner or emergency medical responder who, in the course of responding to a call for service, encounters a domestic animal that is sick or injured may render any first aid service to the domestic animal before the domestic animal is transferred to a veterinarian for further treatment if the service is in the scope of practice of the license or certification of that emergency medical services practitioner or emergency medical responder when applied to human beings.

(3) Immunity from liability.

(a) An ambulance service provider, emergency medical services practitioner, or emergency medical responder is immune from civil or criminal liability for any outcomes resulting from an emergency medical services practitioner or an emergency medical responder rendering first aid to a domestic animal in accordance with sub. (2).

(b) An ambulance service provider, emergency medical services practitioner, or emergency medical responder is immune from civil or criminal liability from declining to render first aid to a domestic animal.