Upon receipt of written notice or order from the health officer the owner of any building specified therein shall take immediate measures for ratproofing the building, and that unless said work and improvements have been completed by the owner in the time specified in the written notice, in no event to be less than fifteen (15) days or within the time to which a written extension may have been granted by the health officer, then the owner shall be deemed guilty of an offense under the provisions of this Chapter. (Ord. A-143 §3, 1949).