AGREEMENT DATED AUGUST 26, 1999

EXHIBIT 10.1

AGREEMENT

This Agreement is entered into by IDEXX Laboratories, Inc. ("IDEXX") and David
E. Shaw ("Shaw") regarding Shaw's reappointment as Chief Executive Officer of
IDEXX, and the planned recruitment and appointment of a person to succeed Shaw
as such Chief Executive Officer. In consideration of Shaw's willingness to serve
as Chief Executive Officer pending the identification and appointment of a
successor (the "Succession"), and to serve as Executive Chairman for a period of
time after the Succession, and for other good and valuable consideration, the
parties agree as follows:

1. From the date hereof until the date of the Succession (the "CEO Term"),
Shaw agrees to serve, and IDEXX agrees to retain Shaw, as Chief Executive
Officer, unless Shaw voluntarily resigns prior to expiration of the CEO
Term. During the CEO Term, Shaw will perform responsibilities consistent
with his position as Chief Executive Officer, and will assist in the
recruitment of a successor.

2. If requested by the Board of Directors in connection with and prior to the
Succession, until December 31, 2001, or such later date as may be mutually
agreed upon (such period, the "Executive Chairman Term" and together with
the CEO Term, the "Term"), Shaw agrees to serve as a part time employee of
IDEXX with the title of "Executive Chairman" unless Shaw voluntarily
resigns prior to expiration of the Term. During the Executive Chairman
Term, Shaw will perform responsibilities consistent with his position as
Executive Chairman, as mutually agreed with the Board of Directors.

3. Shaw's annual base salary during the Term shall initially be $400,000, and
will be subject to change during the Term by mutual agreement. Eligibility
for cash bonuses or stock option grants will be at the discretion of
IDEXX's Board of Directors but consistent with senior officer guidelines.
During the Term, Shaw will participate at current levels in IDEXX benefit
programs including on-site or off-site administrative support and office
facilities.

4. If Shaw's employment is terminated during the Term, by IDEXX, or by Shaw as
a result of breach by IDEXX of this Agreement, then Shaw shall have all the
rights and IDEXX shall have all the obligations provided for in the
Employment Agreement referred to in paragraph 5 below upon a termination of
the Executive's employment thereunder for Good Reason during the Employment
Period. For this purpose a Change of Control will be deemed to have
occurred on the date of termination, and the provisions of the "parachute",
including immediate vesting of all stock options, will become effective.
Additionally, for this purpose, if Shaw shall not be Chief Executive
Officer at the time of such termination, "Annual Base Salary" shall mean
Shaw's annual base salary as Chief Executive Officer.

5. This Agreement supersedes in its entirety the Agreement dated February 17,
1999 between IDEXX and Shaw. The Employment Agreement dated April 25, 1997
between Shaw and IDEXX will remain in effect and, in the event of any
conflict or inconsistency between this Agreement and such Employment
Agreement at or after the Effective Date of the Employment Agreement, the
Employment Agreement shall control.

Agreed to as of August 26, 1999

For IDEXX Laboratories, Inc.:


By: /s/ James L. Moody /s/ David E. Shaw
-------------------------------- ---------------------------------
James L. Moody, Jr., Chairman David E. Shaw
Compensation Committee