POWER OF ATTORNEY SECTION 16 FILINGS

Know all by these presents, that the undersigned hereby constitutes and appoints
Joanne (Jody) P. Acford and Matthew L. Daniel as the undersigned's true and
lawful attorneys in fact to:

(1) prepare, execute in the undersigned's name and on the undersigned's behalf,
and submit to the U.S. Securities and Exchange Commission (the SEC) a Form ID,
including amendments thereto, and any other documents necessary or appropriate
to obtain codes and passwords enabling the undersigned to make electronic
filings with the SEC of reports required by Section 16(a) of the Securities
Exchange Act of 1934 or any rule or regulation of the SEC;

(2) execute for and on behalf of the undersigned, in the undersigned's capacity
as an officer and/or director of Charles River Laboratories International, Inc.
(the Company), Forms 3, 4, and 5 in accordance with Section 16(a) of the
Securities Exchange Act of 1934 and the rules thereunder, and any other forms or
reports the undersigned may be required to file in connection with the
undersigned's ownership, acquisition, or disposition of securities of the
Company;

(3) do and perform any and all acts for and on behalf of the undersigned which
may be necessary or desirable to complete and execute any such Form 3, 4, or 5,
complete and execute any amendment or amendments thereto, and timely file such
form with the United States Securities and Exchange Commission and any stock
exchange or similar authority; and

(4) take any other action of any type whatsoever in connection with the
foregoing which, in the opinion of such attorney in fact, may be of benefit to,
in the best interest of, or legally required by, the undersigned, it being
understood that the documents executed by such attorney in fact on behalf of the
undersigned pursuant to this Power of Attorney shall be in such form and shall
contain such terms and conditions as such attorney in fact may approve in such
attorney in fact's discretion.

The undersigned hereby grants the attorney in fact full power and authority to
do and perform any and every act and thing whatsoever requisite, necessary, or
proper to be done in the exercise of any of the rights and powers herein
granted, as fully to all intents and purposes as the undersigned might or could
do if personally present, with full power of substitution or revocation, hereby
ratifying and confirming all that such attorney in fact, or such attorney in
fact's substitute or substitutes, shall lawfully do or cause to be done by
virtue of this power of attorney and the rights and powers herein granted.  The
undersigned acknowledges that the foregoing attorney in fact, in serving in such
capacity at the request of the undersigned, is not assuming, nor is the Company
assuming, any of the undersigned's responsibilities to comply with Section 16 of
the Securities Exchange Act of 1934.

This Power of Attorney shall remain in full force and effect until the
undersigned is no longer required to file Forms 3, 4, and 5 with respect to the
undersigned's holdings of and transactions in securities issued by the Company,
unless earlier revoked by the undersigned in a signed writing delivered to the
foregoing attorneys in fact.

IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be
executed as of this 16th day of January, 2007.


               /s/George Massaro

               Signature