Section 78. No person holding an auctioneer's license shall receive or offer for sale or sell at public auction, nor shall any person sell at private sale, or lead, ride or drive on any public way, for any purpose except that of conveying the horse to a proper place for its humane keeping or killing, or for medical or surgical treatment, any horse which, by reason of debility, disease or lameness, or for other cause, could not be worked in the commonwealth without violating the laws against cruelty to animals. This section shall not prohibit the purchase of horses by humane societies incorporated under the laws of the commonwealth for the purpose of humanely killing the same. Violation of this section shall be punished by a fine of not less than five nor more than one hundred dollars or by imprisonment for not more than six months. If a licensed auctioneer violates this section, he shall also forfeit his license.