March 9, 2004 Arthur J. Antin C/o VCA Antech, Inc. 12401 West Olympic Boulevard Los Angeles, California 90064-1022 Dear Art: Reference is made to the employment agreement between you and VCA Antech, Inc. ("VCA") dated September 20, 2000 (the...

                                                                   EXHIBIT 10.21

                                VCA ANTECH, INC.
                          00000 XXXX XXXXXXX XXXXXXXXX
                       XXX XXXXXXX, XXXXXXXXXX 00000-0000

                                                                  March 9, 2004


Xxxxxx X. Xxxxx
X/x XXX Xxxxxx, Xxx.
00000 Xxxx Xxxxxxx Xxxxxxxxx
Xxx Xxxxxxx, Xxxxxxxxxx 00000-0000

Dear Art:

         Reference is made to the employment agreement between you and VCA
Antech, Inc. ("VCA") dated September 20, 2000 (the "EMPLOYMENT AGREEMENT"). In
accordance with the loan prohibitions of Section 402 of the Xxxxxxxx-Xxxxx Act
of 2002, you and VCA hereby agree that the terms of Section 4.3 of the
Employment Agreement which permit you to exercise options by the delivery of a
promissory note in the amount of the exercise price are hereby deleted.

                                          VCA Antech, Inc.

                                          By:  /s/ Xxxxxx X. Xxxxx
                                               ---------------------------------
                                               Xxxxxx X. Xxxxx
                                               Chief Executive Officer

Acknowledged and Agreed
to this 9th day of March, 2004
/s/ Xxxxxx X. Xxxxx
---------------------------
Xxxxxx X. Xxxxx