IDEXX Laboratories Submits Application to U.S. Department of Agriculture for Mad Cow Disease Test

WESTBROOK, Maine, February 24, 2004—IDEXX Laboratories, Inc. (NASDAQ: IDXX), today announced that it has submitted a veterinary biological product license application to the U.S. Department of Agriculture for its test for bovine spongiform encephalopathy (BSE), or mad cow disease. The rapid postmortem test detects the presence of the abnormal proteins believed to cause BSE.

IDEXX HerdChek® BSE EIA is an accurate and easy-to-use second-generation diagnostic test that utilizes a novel technology licensed from MicroSens Biotechnologies. "The new test is unique because it simplifies the sample preparation process by eliminating the complex protein digestion steps found in other tests, saving technicians time and effort and reducing the potential for error," said Thomas Mikulka, Senior Marketing Manager, Production Animal Services. The simplified sample preparation eliminates the need for extra laboratory equipment and allows customers to perform high-volume screening with ease and precision.

IDEXX submitted its HerdChek BSE EIA test kit to the European Union (EU) for validation in 2003 and anticipates successfully navigating the EU process, potentially receiving approval to market the product in Europe in late 2004/early 2005.

The IDEXX HerdChek BSE EIA is based on the same technology used in the IDEXX HerdChek Chronic Wasting Disease (CWD) test licensed by the USDA to test for CWD in deer.

Microsens Biotechnologies is a scientific research and licensing company founded in 1998 to develop technologies for the rapid and sensitive detection of transmissible spongiform encephalopathies (TSEs) and other related protein aggregation diseases, such as Alzheimer's disease and Parkinson's disease—collectively known as the "protein conformation disorders." Based at the London Bioscience Innovation Centre, the company operates a dedicated category 3 level containment facility capable of handling bovine spongiform encephalopathy (BSE), Scrapie, Chronic Wasting Disease (CWD) and Creutzfeld-Jacob Disease (CJD) infected materials.

IDEXX Laboratories, Inc., is a worldwide leader in the development and commercialization of innovative, technology-based products and services for animal health. The Company's largest business is focused on companion animal health, combining biotechnology, medical device technology and information technology to aid veterinarians in providing better medicine while building successful practices. IDEXX Laboratories is also focused on employing innovative technologies to monitor production animal health and the safety and quality of drinking water and milk. Headquartered in Westbrook, Maine, IDEXX Laboratories employs over 2,400 people and offers products to customers in more than 100 countries.

This press release contains forward-looking statements as defined in the Private Securities Litigation Reform Act of 1995. These statements are based on management's current expectations of future events, which are subject to risks and uncertainties. If underlying assumptions prove inaccurate, actual results could vary materially from management's expectations. Risks and uncertainties include timing and success of new product introductions, competition and technological change, government regulation and obtaining government approvals, product demand and market acceptance, availability of products and raw materials, and litigation. A further description of these risks and uncertainties and other factors can be found in the Company's Annual Report on Form 10-K for the year ended December 31, 2002 (350 KB) and the Quarterly Report on Form 10-Q for the quarter ended September 30, 2003 (2,277 KB), in the section captioned "Management's Discussion and Analysis of Financial Condition and Results of Operations." The Company assumes no obligation to update any forward-looking statements as a result of new information or future events or developments.