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UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

FORM 10-K/A
AMENDMENT NO. 1

(Mark One)
ý	ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
	FOR THE FISCAL YEAR ENDED DECEMBER 25, 2004
OR
o	TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
	FOR THE TRANSITION PERIOD FROM                        TO

Commission File No. 333-92383

CHARLES RIVER LABORATORIES INTERNATIONAL, INC.
(Exact Name of Registrant as Specified in Its Charter)

Delaware (State or Other Jurisdiction of Incorporation or Organization)	06-1397316 (I.R.S. Employer Identification No.)
251 Ballardvale Street Wilmington, Massachusetts (Address of Principal Executive Offices)	01887 (Zip Code)

(Registrant's telephone number, including area code): (978) 658-6000

Securities registered pursuant to Section 12(b) of the Act:

Title of each class	Name of each exchange on which registered
Common Stock, $0.01 par value	New York Stock Exchange

Securities registered pursuant to Section 12(g) of the Act: None

        Indicate by check mark whether the Registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the Registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes ý    No o

        Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein, and will not be contained, to the best of the Registrant's knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K. o

        Indicate by check mark whether the Registrant is an accelerated filer (as defined in Exchange Act Rule 12b-2). Yes ý    No o

        On June 25, 2004, the aggregate market value of the Registrant's voting common stock held by non-affiliates of the Registrant was approximately $2,150,196,678.

        As of March 1, 2005, there were outstanding 66,109,790 shares of the Registrant's common stock, $0.01 par value per share.

DOCUMENTS INCORPORATED BY REFERENCE

        Portions of the Registrant's Definitive Proxy Statement for its 2005 Annual Meeting of Stockholders scheduled to be held on May 9, 2005 (the "2005 Proxy Statement"), which will be filed with the Securities and Exchange Commission not later than 120 days after December 25, 2004, are incorporated by reference into Part III of this Annual Report on Form 10-K. With the exception of the portions of the 2005 Proxy Statement expressly incorporated into this Annual Report on Form 10-K by reference, such document shall not be deemed filed as part of this Form 10-K.

EXPLANATORY NOTE

        Charles River Laboratories International, Inc. is filing this amendment to Form 10-K for the year ended December 25, 2004, filed with the Securities and Exchange Commission on March 9, 2005, to add the date, March 9, 2005, to the Report of Independent Registered Public Accounting Firm in Item 8.

Report of Independent Registered Public Accounting Firm

To the Board of Directors and Shareholders of
Charles River Laboratories International, Inc.:

        We have completed an integrated audit of Charles River Laboratories International, Inc. and its subsidiaries' 2004 consolidated financial statements and of its internal control over financial reporting as of December 25, 2004 and audits of its December 27, 2003 and December 28, 2002 consolidated financial statements in accordance with the standards of the Public Company Accounting Oversight Board (United States). Our opinions, based on our audits, are presented below.

Consolidated financial statements and financial statement schedule

        In our opinion, the consolidated financial statements listed in the accompanying index, present fairly, in all material respects, the financial position of Charles River Laboratories International, Inc. and its subsidiaries at December 25, 2004 and December 27, 2003, and the results of their operations and their cash flows for each of the three years in the period ended December 25, 2004 in conformity with accounting principles generally accepted in the United States of America. In addition, in our opinion, the financial statement schedule listed in the accompanying index presents fairly, in all material respects, the information set forth therein when read in conjunction with the related consolidated financial statements. These financial statements and financial statement schedule are the responsibility of the Company's management. Our responsibility is to express an opinion on these financial statements and financial statement schedule based on our audits. We conducted our audits of these statements in accordance with the standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement. An audit of financial statements includes examining, on a test basis, evidence supporting the amounts and disclosures in the financial statements, assessing the accounting principles used and significant estimates made by management, and evaluating the overall financial statement presentation. We believe that our audits provide a reasonable basis for our opinion.

Internal control over financial reporting

        Also, in our opinion, management's assessment, included in Management Report on Internal Control Over Financial Reporting appearing under Item 8, that the Company maintained effective internal control over financial reporting as of December 25, 2004 based on criteria established in Internal Control—Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO), is fairly stated, in all material respects, based on those criteria. Furthermore, in our opinion, the Company maintained, in all material respects, effective internal control over financial reporting as of December 25, 2004, based on criteria established in Internal Control—Integrated Framework issued by the COSO. The Company's management is responsible for maintaining effective internal control over financial reporting and for its assessment of the effectiveness of internal control over financial reporting. Our responsibility is to express opinions on management's assessment and on the effectiveness of the Company's internal control over financial reporting based on our audit. We conducted our audit of internal control over financial reporting in accordance with the standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audit to obtain reasonable assurance about whether effective internal control over financial reporting was maintained in all material respects. An audit of internal control over financial reporting includes obtaining an understanding of internal control over financial reporting, evaluating management's assessment, testing and evaluating the design and operating effectiveness of internal control, and performing such other procedures as we consider necessary in the circumstances. We believe that our audit provides a reasonable basis for our opinions.

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        A company's internal control over financial reporting is a process designed to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles. A company's internal control over financial reporting includes those policies and procedures that (i) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the transactions and dispositions of the assets of the company; (ii) provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principles, and that receipts and expenditures of the company are being made only in accordance with authorizations of management and directors of the company; and (iii) provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use, or disposition of the company's assets that could have a material effect on the financial statements.

        Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Also, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate. As described in Management's Report on Internal Control Over Financial Reporting, management has excluded the Inveresk Research Group, Inc. from its assessment of internal control over financial reporting as of December 25, 2004 because it was acquired by the Company in a purchase business combination during 2004. We have also excluded the Inveresk Research Group, LLC from our audit of internal control over financial reporting. The Inveresk Research Group, Inc. is a wholly owned subsidiary whose total assets and total revenues represent 67% and 7.9%, respectively, of the related consolidated financial statement amounts as of and for the year ended December 25, 2004.

PricewaterhouseCoopers LLP
Boston, Massachusetts
March 9, 2005

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SIGNATURES

        Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

CHARLES RIVER LABORATORIES INTERNATIONAL, INC.
By:	/s/  THOMAS F. ACKERMAN Thomas F. Ackerman Senior Vice President and Chief Financial Officer	Date: March 14, 2005

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EXPLANATORY NOTE
Report of Independent Registered Public Accounting Firm
SIGNATURES