IDEXX Laboratories (IDXX) 8-K Changes in registrant's certifying accountant

EXHIBIT 16.1

Office of the Chief Accountant

Securities and Exchange Commission

450 Fifth Street NW

Washington, DC 20549

March 28, 2002

Dear Sir or Madam,

We have read Item 4 included in the attached Form 8-K dated March 28, 2002 of the IDEXX Laboratories, Inc. filed with the Securities and Exchange Commission and are in agreement with the statements contained therein.

Very truly yours,

/s/ Arthur Andersen LLP

Arthur Andersen LLP