The holder of any kennel license may place any dog belonging to such kennel in the possession and keeping of any prospective purchaser for not more than thirty days without such keeper or temporary custodian complying with the provisions of § 22-338, but such dog, during such temporary custody, shall wear around its neck or body a collar or harness of leather or other suitable material, to which shall be attached a tag or plate as specified in § 22-341 or 22-342.