Mass High Tech -- Animal health products company IDEXX Laboratories Inc. says it plans to expand operation at its headquarters in Westbrook, Maine, with a new, $50 million, corporate administrative building that is estimated to encompass 200,000 square feet, and support 500 new jobs. The new building will also allow IDEXX to consolidate 400 positions currently split between One Riverfront Plaza and One Thomas Drive, both also in Westbrook.