When in the opinion of the commissioner it shall be necessary to prevent the spread of any contagious or infectious diseases among the domestic animals of this state, to destroy animals affected with or which have been exposed to any such disease, or which are unconfined in violation of any quarantine order, he shall determine what animals shall be killed and cause the same to be killed and the carcasses disposed of as in his judgment will best protect the health of the domestic animals of the locality.