Two enforcement officers of the Natural Resources Enforcement Division of the Department of Natural Resources from each of the state’s twenty-eight law enforcement units shall be trained by the Department in the identification, capture and humane disposal of feral dogs and these officers shall have the responsibility of answering all complaints concerning feral dogs within the geographical boundaries of their respective law enforcement units. Such enforcement officers shall be held harmless of any personal liability that may occur during the lawful execution of their duties under this act except in case of gross negligence.