<PAGE>
--------------------------------------------------------------------------------
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                                 UNITED STATES
                       SECURITES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                            ------------------------

                                   FORM 10-Q

<TABLE>
<C>        <S>
   /X/     QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15() OF THE
           SECURITIES EXCHANGE ACT OF 1934
</TABLE>

                 FOR THE QUARTERLY PERIOD ENDED MARCH 31, 2001
                                       OR

<TABLE>
<C>        <S>
   / /     TRANSITION REPORT PURSUANT TO SECTION 13 OR 15() OF THE
           SECURITIES EXCHANGE ACT OF 19344
</TABLE>

                        COMMISSION FILE NUMBER 333-91845

                            ------------------------

                        CHARLES RIVER LABORATORIES, INC.

             (Exact Name of Registrant as specified in its Charter)

<TABLE>
<S>                                            <C>
               DELAWARE                                     76-0509980
       (State of Incorporation)                (I.R.S. Employer Identification No.)
</TABLE>

            251 BALLARDVALE STREET, WILMINGTON, MASSACHUSETTS 01887
              (Address of Principal Executive Offices) (Zip Code)

                                  978-658-6000
              (Registrant's Telephone Number, Including Area Code)

                            ------------------------

    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 /X/ No / /

    As of March 31, 2001 there were 1,000 shares of the registrant's common
stock outstanding

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
<PAGE>
                        CHARLES RIVER LABORATORIES, INC.
                                   FORM 10-Q
                 FOR THE QUARTERLY PERIOD ENDED MARCH 31, 2001
                               TABLE OF CONTENTS

<TABLE>
<CAPTION>
                                                                         PAGE
                                                                       --------
<S>      <C>                                                           <C>
Part I.  Financial Information
         Item 1.  Financial Statements...............................      3
         Condensed Consolidated Statements of Income (Unaudited) for
         the three months ended March 25, 2000 and March 31, 2001....      3
         Condensed Consolidated Balance Sheets as of March 31, 2001
         (Unaudited) and December 30, 2000...........................      4
         Condensed Consolidated Statements of Cash Flows (Unaudited)
         as of March 25, 2000 and March 31, 2001.....................      5
         Notes to Unaudited Condensed Consolidated Interim Financial
         Statements..................................................      6
         Item 2.  Management's Discussion and Analysis of Financial
         Condition and Results of Operations.........................     11
Part II  Other Information
         Item 6.  Exhibits and Reports on Form 8-K...................     15
         Signature...................................................     16
</TABLE>

                                       2
<PAGE>
                        CHARLES RIVER LABORATORIES, INC.

            CONDENSED CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED)

          FOR THE THREE MONTHS ENDED MARCH 25, 2000 AND MARCH 31, 2001

                             (DOLLARS IN THOUSANDS)

<TABLE>
<CAPTION>
                                                               THREE MONTHS ENDED
                                                              ---------------------
                                                              MARCH 25,   MARCH 31,
                                                                2000        2001
                                                              ---------   ---------
<S>                                                           <C>         <C>
Net sales related to products...............................   $54,016     $62,078
Net sales related to services...............................    18,486      36,953
                                                               -------     -------
Total net sales.............................................   $72,502     $99,031
Costs and Expenses
  Cost of products sold.....................................    32,193      36,418
  Cost of services provided.................................    12,399      25,951
  Selling, general and administrative.......................    11,813      15,460
  Amortization of goodwill and intangibles..................       865       1,828
                                                               -------     -------
Operating income............................................    15,232      19,374
Other income (expense)
  Interest income...........................................       142         253
  Interest expense..........................................    (9,301)     (6,958)
  Other income (expenses)...................................       (30)        555
                                                               -------     -------
Income before income taxes, minority interests, earnings
  from equity investments and extraordinary item............     6,043      13,224
Provision for income taxes..................................     3,341       5,555
                                                               -------     -------
Income before minority interests, earnings from equity
  investments and extraordinary item........................     2,702       7,669
Minority interests..........................................      (217)       (564)
Earnings from equity investments, net of tax................       641          83
                                                               -------     -------
Income before extraordinary item............................     3,126       7,188
Extraordinary loss, net of tax benefit of $128..............        --        (237)
                                                               -------     -------
Net Income..................................................   $ 3,126     $ 6,951
</TABLE>

            See Notes to Condensed Consolidated Financial Statements

                                       3
<PAGE>
                        CHARLES RIVER LABORATORIES, INC.

                     CONDENSED CONSOLIDATED BALANCE SHEETS

                             (DOLLARS IN THOUSANDS)

<TABLE>
<CAPTION>
                                                              DECEMBER 30,    MARCH 31,
                                                                  2000          2001
                                                              ------------   -----------
                                                                             (UNAUDITED)
<S>                                                           <C>            <C>
ASSETS
Current assets
  Cash and cash equivalents.................................   $  33,129      $  72,399
  Trade receivables, less allowances of $1,036 and $1,012
    respectively............................................      45,949         78,295
  Inventories...............................................      33,890         34,287
  Deferred income taxes.....................................       2,055          2,055
  Due from affiliates.......................................          83             83
  Other current assets......................................       4,631          8,083
                                                               ---------      ---------
    Total current assets....................................     119,737        195,202
Property, plant and equipment, net..........................     117,001        139,694
Goodwill and other intangibles, less accumulated
  amortization of $10,810 and $12,624 respectively..........      41,893         91,529
Investments in affiliates...................................       2,442          2,514
Deferred tax asset..........................................      91,371         87,422
Deferred financing costs....................................       7,979          8,203
Other assets................................................      16,529         17,165
                                                               ---------      ---------
    Total assets............................................   $ 396,952      $ 541,729
                                                               =========      =========
LIABILITIES AND SHAREHOLDERS' EQUITY
Current liabilities
  Current portion of long-term debt.........................   $     231      $  16,153
  Current portion of capital lease obligation...............         181          1,633
  Accounts payable..........................................      10,767         10,814
  Accrued compensation......................................      16,997         16,300
  Deferred income...........................................       5,223         11,760
  Accrued interest..........................................       3,451          7,059
  Accrued liabilities.......................................      24,187         33,078
  Accrued income taxes......................................       3,283          2,503
                                                               ---------      ---------
    Total current liabilities...............................      64,320         99,300
Long-term debt..............................................     201,957        228,302
Capital lease obligations...................................         543          2,403
Accrued ESLIRP..............................................      10,116         10,391
Other long-term liabilities.................................       3,415          3,886
                                                               ---------      ---------
    Total liabilities.......................................     280,351        344,282
                                                               ---------      ---------

Commitments and contingencies
Minority interests..........................................      13,330         11,962
Shareholders' equity
  Common stock, $1 par value, 1000 shares authorized and
    outstanding.............................................           1              1
  Capital in excess of par value............................     237,221        315,818
  Retained earnings.........................................    (117,689)      (110,739)
  Loans to officers.........................................        (920)          (620)
  Accumulated other comprehensive income....................     (15,342)       (18,975)
                                                               ---------      ---------
    Total shareholders' equity..............................     103,271        185,485
                                                               ---------      ---------
      Total liabilities and shareholders' equity............   $ 396,952      $ 541,729
                                                               =========      =========
</TABLE>

            See Notes to Condensed Consolidated Financial Statements

                                       4
<PAGE>
                        CHARLES RIVER LABORATORIES, INC.
          CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED)
                             (DOLLARS IN THOUSANDS)

<TABLE>
<CAPTION>
                                                               THREE MONTHS ENDED
                                                              ---------------------
                                                              MARCH 25,   MARCH 31,
                                                                2000        2001
                                                              ---------   ---------
<S>                                                           <C>         <C>
CASH FLOWS RELATING TO OPERATING ACTIVITIES
  Net income................................................   $ 3,126    $  6,951
    Adjustments to reconcile net income to net cash provided
      by operating activities:
  Depreciation and amortization.............................     3,764       5,439
  Amortization of debt issuance costs and discounts.........       481         453
  Provision for doubtful accounts...........................        82         199
  Extraordinary loss, net of tax............................        --         237
  Earnings from equity investments..........................      (641)        (83)
  Minority interests........................................       217         564
  Deferred income taxes.....................................       (42)      4,303
  Property, plant, and equipment write-downs and
    disposals...............................................        --         195
  Other non-cash items......................................        12          --
    Changes in assets and liabilities:
  Trade receivables.........................................    (6,564)     (5,559)
  Inventories...............................................      (104)       (555)
  Due from affiliates.......................................       128          --
  Other current assets......................................      (583)     (2,663)
  Other assets..............................................      (102)       (426)
  Accounts payable..........................................    (2,585)     (2,581)
  Accrued compensation......................................      (413)     (2,035)
  Accrued ESLIRP............................................       167         275
  Deferred income...........................................      (782)       (208)
  Accrued interest..........................................     4,478       3,604
  Accrued liabilities.......................................      (740)        678
  Accrued income taxes......................................     2,116        (731)
  Other long-term liabilities...............................      (154)       (229)
                                                               -------    --------
  Net cash provided by operating activities.................   $ 1,861    $  7,828
                                                               -------    --------
CASH FLOWS RELATING TO INVESTING ACTIVITIES
  Capital expenditures......................................    (2,786)     (4,253)
  Contingent payments for prior year acquisitions...........        --        (250)
  Acquisition of business, net of cash acquired.............    (6,011)    (51,265)
  Proceeds from sale of animal colony.......................     7,000          --
                                                               -------    --------
  Net cash used in investing activities.....................   $(1,797)   $(55,768)
                                                               -------    --------
CASH FLOWS RELATING TO FINANCING ACTIVITIES
  Proceeds from long term debt..............................     4,114      39,831
  Payments on long-term debt and revolving credit
    facility................................................      (300)    (12,099)
  Payment of deferred financing costs.......................        --        (891)
  Payments on capital lease obligations.....................       (93)       (701)
  Capital contribution from parent..........................        --      62,222
  Payments on officer loans.................................        --         300
                                                               -------    --------
  Net cash provided by financing activities.................   $ 3,721    $ 88,662
                                                               -------    --------
Effect of exchange rate changes on cash and cash
  equivalents...............................................      (337)     (1,452)
Net change in cash and cash equivalents.....................     3,448      39,270
                                                               -------    --------
Cash and cash equivalents, beginning of period..............    15,010      33,129
                                                               -------    --------
CASH AND CASH EQUIVALENTS, END OF PERIOD....................   $18,458    $ 72,399
                                                               =======    ========
SUPPLEMENTAL CASH FLOW INFORMATION
  Cash paid for interest....................................   $ 4,317    $  6,747
  Cash paid for taxes.......................................       980       2,339
</TABLE>

            See Notes to Condensed Consolidated Financial Statements

                                       5
<PAGE>
                        CHARLES RIVER LABORATORIES, INC.

     NOTES TO UNAUDITED CONDENSED CONSOLIDATED INTERIM FINANCIAL STATEMENTS

                             (DOLLARS IN THOUSANDS)

1.  BASIS OF PRESENTATION

    The condensed consolidated interim financial statements are unaudited, and
certain information and footnote disclosure related thereto normally included in
financial statements prepared in accordance with generally accepted accounting
principles in the United States, have been omitted in accordance with
Rule 10-01 of Regulation S-X. In the opinion of management, the accompanying
unaudited condensed consolidated financial statements were prepared following
the same policies and procedures used in the preparation of the audited
financial statements and reflect all adjustments (consisting of normal recurring
adjustments) considered necessary to present fairly the financial position of
Charles River Laboratories, Inc. ("the Company"). The results of operations for
the interim periods are not necessarily indicative of the results for the entire
fiscal year. These condensed consolidated financial statements should be read in
conjunction with the Company's Annual Report on Form 10K for the year ended
December 30, 2000.

2.  CHARLES RIVER LABORATORIES INTERNATIONAL, INC.'S PUBLIC OFFERINGS

    On March 21, 2001, Charles River International, Inc. ("CRLI"), our parent
company, consummated a public offering ("the Follow-on Offering") of 3,500,000
shares of its common stock at a price of $19.00 per share. As part of the
Follow-on Offering, existing shareholders sold an additional 4,550,000 shares of
common stock, which included the exercise of the over-allotment option of
1,050,000 shares. CRLI received proceeds of $62,222, net of underwriter's
commissions and follow-on offering costs. These proceeds were contributed to the
Company and recorded as a capital contribution. The Company has used a portion
of the contribution to repay $3,000 and $9,000 of the Term Loan A and Term Loan
B, respectively. As a result of this repayment the Company has recorded an
extraordinary loss before tax of $365 due to the write-off of deferred financing
costs. This extraordinary loss has been recorded net of a tax benefit of $128.
The Company plans to use the remainder of the proceeds to repay a portion of its
remaining indebtedness.

    On June 28, 2000, CRLI consummated an initial public offering (the "IPO") of
16,100,000 shares of its common stock at a price of $16.00 per share. CRLI used
part of the proceeds to make a capital contribution of $122,288 to the Company.
The Company used the contribution plus cash on hand of $300 to repay $115,500 of
its existing debt, including issuance discounts, and to pay premiums of $7,088.

3.  ACQUISITIONS AND DISPOSALS

ACQUISITIONS

    On January 8, 2001, the Company purchased 100% of the common stock of
Pathology Associates International Corporation ("PAI"). Consideration, including
acquisition expenses, of $35,238 was paid with respect to this acquisition
consisting of $25,557 in cash and a $12,000 callable convertible note. The
convertible note has a five year term and bears interest at 2% per annum. As the
stated interest rate attached to this $12,000 note is lower than the prevailing
borrowing rate available to the Company, a discount of $2,319, which is being
amortized over the life of the note, was recorded upon issuance. Consideration
of $9,681 was recorded with respect to the convertible note. Under certain
conditions the note is convertible into shares of CRLI's common stock at a price
of $23.38. The cash consideration was funded in part through a $15,000 drawdown
from the Company's revolving credit facility. This acquisition was recorded as a
purchase business combination and the Company is consolidating the operations of
PAI from the date of acquisition.

                                       6
<PAGE>
                        CHARLES RIVER LABORATORIES, INC.

     NOTES TO UNAUDITED CONDENSED CONSOLIDATED INTERIM FINANCIAL STATEMENTS
                                  (CONTINUED)

                             (DOLLARS IN THOUSANDS)

    Effective February 27, 2001 the Company acquired Primedica Corporation
("Primedica") for consideration, including acquisition expenses, of $51,107.
Consideration was comprised of $25,708 of cash, $16,375 of restricted CRLI
common stock and $9,024 in assumed debt. Consideration paid in the form of CRLI
restricted common stock was recorded in the Company's Condensed Consolidated
Interim Financial Statements as a capital contribution from parent. This
acquisition was recorded as a purchase business combination and the Company is
consolidating the operations of Primedica. The acquisition agreement requires
the Company to file a registration statement under the Securities Act covering
the restricted common stock no later than July 1, 2001. In addition, the Company
has the right to repurchase, at any time prior to July 1, 2001, the restricted
common stock at a price equal to the greater of $24.05 or fair market value.
Furthermore, in connection with the Primedica acquisition the Company amended
its senior credit facility to add a $25,000 Term Loan C and to increase the
interest rate on the Term Loan A. The interest rate on the Term Loan A, as
amended, and the Term Loan C is based on the Libor rate plus 1.75% and 3.25%,
respectively.

    As of March 31, 2001, the Company is in process of finalizing the purchase
price allocation associated with the PAI and Primedica acquisitions. The Company
believes the accounting for these acquisitions will be finalized during the
second quarter of 2001. The Company's preliminary allocation of purchase price
for these acquisitions, based on valuations which have not yet been finalized,
is as follows:

<TABLE>
<CAPTION>
                                                             PAI      PRIMEDICA
                                                           --------   ---------
<S>                                                        <C>        <C>
Net current assets.......................................  $ 3,126     $ 6,415
Property, plant and equipment............................    1,276      24,637
Non-current assets.......................................      159          35
Non-current liabilities..................................       --        (859)
                                                           -------     -------
Estimated fair value, net tangible assets acquired.......    4,561      30,228
Goodwill and other intangible assets.....................   30,677      20,879
Consideration............................................   35,238      51,107
Less: assumed debt.......................................       --      (9,024)
                                                           -------     -------
                                                           $35,238     $42,083
                                                           =======     =======
</TABLE>

    Net current liabilities in the above preliminary purchase price allocation
includes a $530 liability recorded in accordance with EITF 95-3 "Recognition of
Liabilities in Connection with a Purchase Business Combination" ("EITF 95-3").
This liability relates to severance benefits to be provided to certain Primedica
employees. These benefits are expected to be paid during 2001.

    Goodwill and other intangible assets recorded in the accompanying condensed
consolidated interim financial statements associated with these acquisitions are
being amortized over their estimated useful lives ranging from 2 to 20 years.

    The following selected unaudited pro forma consolidated results of
operations are presented as if each of the acquisitions had occurred as of the
beginning of the period immediately preceding the period of acquisition after
giving effect to certain adjustments for the amortization of goodwill,
additional interest expense and related income tax effects. The pro forma data
is for informational purposes only and does not necessarily reflect the results
of operations had the companies operated as

                                       7
<PAGE>
                        CHARLES RIVER LABORATORIES, INC.

     NOTES TO UNAUDITED CONDENSED CONSOLIDATED INTERIM FINANCIAL STATEMENTS
                                  (CONTINUED)

                             (DOLLARS IN THOUSANDS)

one during the period. No effect has been given for synergies, if any, that may
have been realized through the acquisitions.

<TABLE>
<CAPTION>
                                                         THREE MONTHS ENDED
                                                   -------------------------------
                                                   MARCH 25, 2000   MARCH 31, 2001
                                                   --------------   --------------
<S>                                                <C>              <C>
Net sales........................................     $94,849          $111,199
Income before extraordinary item.................       2,079             6,981
Net income.......................................       2,079             6,744
</TABLE>

DISPOSALS

    During the fourth quarter of 2000, the Company recorded a pre-tax
restructuring charge of $1,290 associated with the closing of a facility in
France. As of December 31, 2000, $1,078 of this charge was unpaid and included
in the consolidated balance sheet as an accrued liability. In the first quarter
of 2001 the Company recorded an additional charge of $799 relating to additional
severance payments negotiated with employees following labor disputes arising in
the first quarter. These charges have been recorded in selling, general and
administrative expenses in the accompanying condensed consolidated interim
statements of income. A summary of the activity associated with these
restructuring reserves is as follows:

<TABLE>
<CAPTION>
                                                              EMPLOYEE
                                                             SEPARATIONS    OTHER      TOTAL
                                                             -----------   --------   --------
<S>                                                          <C>           <C>        <C>
December 30, 2000..........................................     $  993       $85       $1,078
Additional charges recorded--first quarter 2001............        799        --          799
Amounts paid--first quarter 2001...........................         --        --           --
                                                                ------       ---       ------
March 31, 2001.............................................     $1,792       $85       $1,877
                                                                ======       ===       ======
</TABLE>

4.  SUPPLEMENTAL BALANCE SHEET INFORMATION

    The composition of inventories is as follows:

<TABLE>
<CAPTION>
                                                 DECEMBER 30, 2000   MARCH 31, 2001
                                                 -----------------   --------------
<S>                                              <C>                 <C>
Raw materials and supplies.....................       $ 4,052           $ 4,283
Work in process................................           910             1,161
Finished products..............................        28,928            28,843
                                                      -------           -------
Inventories....................................       $33,890           $34,287
                                                      =======           =======
</TABLE>

    Inventories are stated at the lower of cost or market. Cost is determined
principally on the average cost method. Costs for large animals are accumulated
in inventory until the large animals are sold.

                                       8
<PAGE>
                        CHARLES RIVER LABORATORIES, INC.

     NOTES TO UNAUDITED CONDENSED CONSOLIDATED INTERIM FINANCIAL STATEMENTS
                                  (CONTINUED)

                             (DOLLARS IN THOUSANDS)

    The composition of property, plant and equipment is as follows:

<TABLE>
<CAPTION>
                                                 DECEMBER 30, 2000   MARCH 31, 2001
                                                 -----------------   --------------
<S>                                              <C>                 <C>
Land...........................................      $   9,367         $   9,100
Buildings......................................        142,569           146,331
Machinery and equipment........................         95,407           102,401
Leasehold improvements.........................          5,747            15,706
Furniture and fixtures.........................          1,992             2,587
Vehicles.......................................          2,378             2,359
Construction in progress.......................          5,102             6,231
                                                     ---------         ---------
                                                       262,562           284,715
Less accumulated depreciation..................       (145,561)         (145,021)
                                                     ---------         ---------
Net property, plant and equipment..............      $ 117,001         $ 139,694
                                                     =========         =========
</TABLE>

5.  COMMITMENTS AND CONTINGENCIES

    INSURANCE

    The Company maintains insurance for workers' compensation, auto liability,
employee medical and general liability. The per claim loss limits are $250, with
annual aggregate loss limits of $1,500. Related accruals were $3,461 and $3,421
on December 30, 2000 and March 31, 2001, respectively. Separately, the Company
has provided a letter of credit in favor of the insurance carriers in the amount
of $2,500.

    LITIGATION

    Various lawsuits, claims and proceedings of a nature considered normal to
its business are pending against the Company. In the opinion of management, the
outcome of such proceedings and litigation currently pending will not materially
affect the Company's condensed consolidated financial statements.

    The Company is currently under a court order issued in June 1997 to remove
its large animal operations from two islands located in the Florida Keys and to
refoliate the islands. The Company has removed its large animal operations from
the island in the First Quarter of 2000. The Company continues to hold
discussions with the state of Florida and federal authorities regarding the
extent of refoliation required on the islands and believes the reserves recorded
in the accompanying condensed consolidated financial statements are sufficient
to provide for the estimated exposure in connection with the refoliation. The
Company has provided a letter of credit in regards to the completion of the
refoliation on the island for $350.

6.  BUSINESS SEGMENT INFORMATION

    The following table presents sales and other financial information by
product line segment for the three month periods ended March 25, 2000 and
March 31, 2001. Sales to unaffiliated customers

                                       9
<PAGE>
                        CHARLES RIVER LABORATORIES, INC.

     NOTES TO UNAUDITED CONDENSED CONSOLIDATED INTERIM FINANCIAL STATEMENTS
                                  (CONTINUED)

                             (DOLLARS IN THOUSANDS)

represent net sales originating in entities primarily engaged in either research
models or biomedical products and services.

<TABLE>
<CAPTION>
                                                      THREE MONTH PERIOD ENDED
                                                   -------------------------------
                                                   MARCH 25, 2000   MARCH 31, 2001
                                                   --------------   --------------
<S>                                                <C>              <C>
Research Models
  Net sales......................................     $41,104          $49,474
  Gross margin...................................      16,822           20,549
  Operating income...............................      11,999           13,271
  Depreciation and amortization..................       2,090            2,405
  Capital expenditures...........................       1,438            1,913
Biomedical Products and Services
  Net sales......................................      31,398           49,557
  Gross margin...................................      11,088           16,113
  Operating income...............................       5,940            8,480
  Depreciation and amortization..................       1,674            3,034
  Capital expenditures...........................       1,348            2,340
</TABLE>

    Total assets attributable to the research models segment as of December 30,
2000 and March 31, 2001 were $300,107 and $336,263 respectively. Total assets
attributable to the biomedical products and services segment as of December 30,
2000 and March 31, 2001 were $96,845 and $205,466 respectively.

    A reconciliation of segment operating income to consolidated operating
income is as follows:

<TABLE>
<CAPTION>
                                                      THREE MONTH PERIOD ENDED
                                                   -------------------------------
                                                   MARCH 25, 2000   MARCH 31, 2001
                                                   --------------   --------------
<S>                                                <C>              <C>
Total segment operating income...................     $17,939          $21,751
Unallocated corporate overhead...................      (2,707)          (2,377)
                                                      -------          -------
Consolidated operating income....................     $15,232          $19,374
                                                      =======          =======
</TABLE>

7.  COMPREHENSIVE INCOME/(LOSS)

    The components of comprehensive income for the three month periods ended
March 25, 2000 and March 31, 2001 are set forth below:

<TABLE>
<CAPTION>
                                                      THREE MONTH PERIOD ENDED
                                                   -------------------------------
                                                   MARCH 25, 2000   MARCH 31, 2001
                                                   --------------   --------------
<S>                                                <C>              <C>
Net income/(loss)................................     $ 3,126          $ 6,951
Foreign currency translation.....................      (1,873)          (3,634)
                                                      -------          -------
Comprehensive income/(loss)......................     $ 1,253          $ 3,317
                                                      =======          =======
</TABLE>

8.  SUBSEQUENT EVENTS

    On April 27 ,2001, the Company's French subsidiaries obtained a favorable
legal judgement in a contract dispute, with a damages award of 26,500 French
Francs or approximately $3,500. The Company expects the defendant to appeal the
decision. No amounts have been recorded in the quarter ended March 31, 2001,
with respect to this judgement.

                                       10
<PAGE>
   MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF
                                   OPERATIONS

THREE MONTHS ENDED MARCH 31, 2001 COMPARED TO THE THREE MONTHS ENDED MARCH 25,
  2000

    NET SALES.  Net sales for the three months ended March 31, 2001 were
$99.0 million, an increase of $26.5 million, or 36.6%, from $72.5 million for
the three months ended March 25, 2000.

RESEARCH MODELS.  Net sales of research models for the three months ended
March 31, 2001 were $49.5 million, an increase of $8.4 million, or 20.4%, from
$41.1 million for the three months ended March 25, 2000. Small animal research
model sales increased in North America by 13.5% due to improved pricing, a shift
to higher priced specialty units and an increase in unit volume. Excluding
negative currency translation of $1.1 million, small animal research model sales
in Europe increased 13.7%. Small animal research model sales in Japan, which we
began consolidating during the first quarter of 2000, were $11.1 million for the
three months ended March 31, 2001. Our large animal breeding and import
conditioning business sales decreased by $2.0 million for the three months ended
March 31, 2001 due to the closure of our conditioning facility in the UK during
the second quarter of 2000 and the sale of our Florida breeding colony, which
was sold in the first quarter of 2000.

BIOMEDICAL PRODUCTS AND SERVICES.  Net sales of biomedical products and services
for the three months ended March 31, 2001 were $49.5 million, an increase of
$18.1 million, or 57.6%, from $31.4 million for the three months ended
March 25, 2000. We acquired two businesses during the first quarter of 2001,
Pathology Associates International Corporation ("PAI") on January 8 and
Primedica Corporation ("Primedica") on February 27, which contributed
$16.1 million of sales in the quarter. On a proforma basis, giving effect to the
acquisitions, sales of biomedical products and services increased 15.0% over
last year, before the effects of unfavorable currency.

    COST OF PRODUCTS SOLD AND SERVICES PROVIDED.  Cost of products sold and
services provided for the three months ended March 31, 2001 was $62.4 million,
an increase of $17.8 million, or 39.9%, from $44.6 million for the three months
ended March 25, 2000. Cost of products sold and services provided for the three
months ended March 31, 2001 were 63.0% of the net sales compared to 61.5% for
the three months ended March 25, 2000.

RESEARCH MODELS.  Cost of products sold and services provided for research
models for the three months ended March 31, 2001 was $28.9 million, an increase
of $4.6 million, or 18.9%, compared to $24.3 million for the three months ended
March 25, 2000. Cost of products sold and services provided for the three months
ended March 31, 2001 improved to 58.4% of net sales compared to 59.1% of net
sales for the three months ended March 25, 2000. Cost of products sold and
services provided increased at a lower rate than net sales due to a more
favorable product mix, improved pricing as well as improved capacity
utilization.

BIOMEDICAL PRODUCTS AND SERVICES.  Cost of products sold and services provided
for biomedical products and services for the three months ended March 31, 2001
was $33.4 million, an increase of $13.1 million, or 64.5%, compared to
$20.3 million for the three months ended March 25, 2000. Cost of products sold
and services provided as a percentage of net sales increased to 67.5% for the
three months ended March 31, 2001 from 64.6% for the three months ended
March 25, 2000. Cost of products sold and services provided increased as a
percentage of sales for the three months ended March 31, 2001 due to the
addition of PAI and Primedica which operate at lower gross margins than the
remainder of our biomedical products and services businesses.

    SELLING, GENERAL AND ADMINISTRATIVE EXPENSES.  Selling, general and
administrative expenses for the three months ended March 31, 2001 were
$15.5 million, an increase of $3.7 million, or 31.4%, from $11.8 million for the
three months ended March 25, 2000. Selling, general and administrative expenses
for the three months ended March 31, 2001 were 15.7% of net sales compared to
16.3% of net sales for the three months ended March 25, 2000.

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<PAGE>
RESEARCH MODELS.  Selling, general and administrative expenses for research
models for the three months ended March 31, 2001 were $7.1 million, an increase
of $2.3 million, or 47.9%, compared to $4.8 million for the three months ended
March 25, 2000. Selling, general and administrative expenses for the three
months ended March 31, 2001 were 14.3% of net sales, compared to 11.7% for the
three months ended March 25, 2000, principally due to a $0.8 million
restructuring charge in France.

BIOMEDICAL PRODUCTS AND SERVICES.  Selling, general and administrative expenses
for biomedical products and services for the three months ended March 31, 2001
were $6.0 million, an increase of $1.7 million, or 39.5%, compared to
$4.3 million for the three months ended March 25, 2000. Selling, general and
administrative expenses for the three months ended March 31, 2001 decreased to
12.1% of net sales, compared to 13.7% of net sales for the three months ended
March 25, 2000, due to greater economies of scale realized through our
acquisitions of PAI and Primedica.

UNALLOCATED CORPORATE OVERHEAD.  Unallocated corporate overhead, which consists
of various corporate expenses and income items, was $2.4 million of expense for
the three months ended March 31, 2001, compared to $2.7 million expense for the
three months ended March 25, 2000 due mainly to pension income from favorable
investment returns.

    AMORTIZATION OF GOODWILL AND OTHER INTANGIBLES.  Amortization of goodwill
and other intangibles for the three months ended March 31, 2001 was
$1.8 million, an increase of $0.9 million from $0.9 million for the three months
ended March 25, 2000. The increase was due to the effect of additional
amortization of goodwill and other intangibles resulting from our PAI and
Primedica acquisitions.

    OPERATING INCOME.  Operating income for the three months ended March 31,
2001 was $19.4 million, an increase of $4.2 million, or 27.6%, from
$15.2 million for the three months ended March 25, 2000. Operating income for
the three months ended March 31, 2001 was 19.6% of net sales, compared to 21.0%
of net sales for the three months ended March 25, 2000. Operating income as a
percentage of net sales decreased due to the additional amortization expense
incurred as a result of our acquisitions and the restructuring charge in France.

RESEARCH MODELS.  Operating income from sales of research models for the three
months ended March 31, 2001 was $13.3 million, an increase of $1.3 million, or
10.8%, from $12.0 million for the three months ended March 25, 2000. Operating
income from sales of research models for the three months ended March 31, 2001
was 26.9% of net sales, compared to 29.2% for the three months ended March 25,
2000, principally due to the restructuring charge in France.

BIOMEDICAL PRODUCTS AND SERVICES.  Operating income from sales of biomedical
products and services for the three months ended March 31, 2001 was
$8.5 million, an increase of $2.6 million, or 44.1%, from $5.9 million for the
three months ended March 25, 2000. Operating income from sales of biomedical
products and services for the three months ended March 31, 2001 decreased to
17.2% of net sales, compared to 18.8% of net sales for the three months ended
March 25, 2000, due to the additional amortization expense resulting from the
acquisitions of PAI and Primedica.

    INTEREST EXPENSE.  Interest expense for the three months ended March 31,
2001 was $7.0 million, compared to $9.3 million for the three months ended
March 25, 2000. The $2.3 million decrease is primarily due to the reduction of
debt in the third quarter of 2000, which was funded through a capital
contribution from Charles River Laboratories International, Inc. ("CRLI").

    OTHER INCOME.  During the three months ended March 31, 2001, we received
insurance proceeds relating to damaged production facilities, which resulted in
a net gain of $0.5 million.

    INCOME TAXES.  The effective tax rate for the three months ended March 31,
2001 of 42.0% compares favorably to the effective tax rate of 55.3% for the
three months ended March 25, 2000. The impact of leverage for the three months
ended March 25, 2000 had an unfavorable effect on our tax

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<PAGE>
rate by lowering our pretax income and increasing the impact of the permanent
differences on the effective tax rate.

    INCOME BEFORE THE EXTRAORDINARY LOSS.  Income before the extraordinary loss
for the three months ended March 31, 2001 was $7.2 million, an increase of
$4.1 million from $3.1 million for the three months ended March 25, 2000. The
increase is driven by the increase in operating income, the decrease in interest
expense and the decrease in our effective tax rate.

    EXTRAORDINARY LOSS.  We recorded an extraordinary loss of $0.2 million
during the first quarter of 2001. The pre-tax loss of $0.4 million is the result
of the write off of deferred financing costs associated with the debt
repayments, net of tax benefits of $0.2 million.

    NET INCOME.  Net income for the three months ended March 31, 2001 was
$7.0 million, an increase of $3.9 million from net income of $3.1 million for
the three months ended March 25, 2000. The increase is attributable to the
factors mentioned above.

LIQUIDITY AND CAPITAL RESOURCES

    Cash and cash equivalents of Charles River totaled $72.4 million at
March 31, 2001 compared with $33.1 million at December 30, 2000. Our principal
sources of liquidity are cash from operations as well as cash provided by our
public offerings.

    Net cash provided by operating activities for the three months ended
March 31, 2001 and March 25, 2000 were $7.8 million and $1.9 million
respectively. The increase in cash provided by operations is primarily a result
of our improved performance during the first three months of 2001.

    Net cash used in investing activities during the three months ended
March 31, 2001 and March 25, 2000 were $55.8 million and $1.8 million
respectively. The increase in cash used is a result of our business
acquisitions. During the first quarter of 2001 we used net cash of
$51.3 million to acquire PAI and Primedica. In the first quarter of 2000 we used
net cash of $6.0 million to acquire an additional 16% of equity in Charles River
Japan. Also in order to grow our existing businesses we have incurred capital
expenditures for the three month periods ended March 31, 2001 and March 30, 2000
of $4.3 million and $2.8 million, respectively.

    Net cash provided by financing activities during the three months ended
March 31, 2001 and March 25, 2000 were $88.7 million and $3.7 million,
respectively. During March 2001, CRLI consummated a follow-on public offering
which netted $62.2 million in proceeds. As a result of the follow-on offering,
we received a capital contribution of $62.2 million from CRLI. We used
$12.0 million of the contribution to repay part of our bank financing. We plan
to use the remaining contribution to repay portions of our existing debt. Also
the Company received $40.0 million from our bank financing which was used to
purchase PAI and Primedica.

    We anticipate that our operating cash flow, along with borrowings under our
credit facility, will be sufficient to meet our anticipated future operating
expenses, capital expenditures and debt service obligations as they become due.

QUANTITATIVE AND QUALITATIVE DISCLOSURE ABOUT MARKET RISK

    We are subject to market risks arising from changes in interest rates and
foreign currency exchange rates. Our primary interest rate exposure results from
changes in LIBOR or the base rate which are used to determine the applicable
interest rates under our term loans and revolving credit facility. We have
entered into an interest rate protection agreement designed to protect us
against fluctuations in interest rates with respect to at least 50% of the
aggregate principal amount of the term loans and the senior subordinated notes.
Our potential loss over one year that would result from a hypothetical,
instantaneous and unfavorable change of 100 basis points in the interest rate on
all of our variable rate

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<PAGE>
obligations would be approximately $1.5 million. Fluctuations in interest rates
will not affect the interest payable on the senior subordinated notes, which is
fixed.

    We do not use financial instruments for trading or other speculative
purposes.

    We also have exposure to some foreign currency exchange rate fluctuations
for the cash flows received from our foreign affiliates. This risk is mitigated
by the fact that their operations are conducted in their respective local
currencies, and it is not our intention to repatriate earnings prospectively.
Currently, we do not engage in any foreign currency hedging activities as we do
not believe that our foreign currency exchange rate risk is material.

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<PAGE>
CHARLES RIVER LABORATORIES INTERNATIONAL, INC. FORM 10-Q
For the Quarterly Period Ended March 31, 2001

ITEM 6. EXHIBITS AND REPORTS ON FORM 8-K

(a) The following exhibits are included as part of this Report on Form 10-Q:

<TABLE>
<C>       <S>
10.1**    Amended and Restated Credit Agreement, dated as of
          February 2, 2001, among Charles River Laboratories, Inc.,
          the various financial institutions, Union Bank of
          California, N.A., Credit Suisse First Boston, and National
          City Bank, (Filed as Exhibit 10.1).
10.2*     Amendment No. 1 to Credit Agreement among Charles River
          Laboratories, Inc., the various financial institutions,
          Union Bank of California, N.A., Credit Suisse First Boston,
          and National City Bank, dated April 18, 2001.
99.1*     Amendment No. 1 to the 2000 Incentive Plan of Charles River
          Laboratories International, Inc. dated May 8, 2001.
</TABLE>

------------------------

*   Filed herewith.

**  Previously filed as an exhibit to, and incorporated herein by reference
    from, the Charles River Laboratories International, Inc.'s Registration
    Statement on Form S-3 (File No. 333-55670), as amended, filed February 15,
    2001.

(b) We filed the following Current Reports on Form 8-K during the quarter ended
    March 31, 2001:

    - We filed a Current Report on Form 8-K on January 9, 2001, to announce,
      pursuant to Item 9, the completion of the acquisition of Pathology
      Associates International Corporation. On March 12, 2001, we filed an 8-K/A
      to amend this Form 8-K to change the Item number under which the
      information was filed from Item 9 ("Regulation FD Disclosure") to Item 5
      ("Other Events").

    - We filed a Current Report on Form 8-k on February 7, 2001, to announce,
      pursuant to Item 9, the signing of a definative agreement to acquire
      Primedica Corporation from Genzyme Transgenics Corporation. On March 12,
      2001, we filed an 8-K/A to amend this Form 8-K to change the Item number
      under which the information was filed from Item 9 ("Regulation FD
      Disclosure") to Item 5 ("Other Events").

    - We filed a Current Report on Form 8-K on February 20, 2001 to report
      pursuant to Item 5, our consolidated financial statements for the fiscal
      year ended December 30, 2000 and our Management's Discussions and Analysis
      of Financial Condition and Results of Operations. We filed our
      consolidated financial statements for the year ended December 31, 2000
      with this report.

    - We filed a Current Report on Form 8-K on February 28, 2001 to announce,
      pursuant to Item 9, our completion of the acquisition of Primedica
      Corporation from Genzyme Transgenics Corporation.

    - We filed a Current Report on Form 8-K/A on March 12, 2001, to amend the
      Form 8-K to change the Item number under which the information was filed
      from Item 9 ("Regulation FD Disclosure") to Item 5 ("Other Events").

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<PAGE>
                                   SIGNATURE

    Pursuant to the requirements 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.

<TABLE>
<S>                                            <C>
                                               CHARLES RIVER LABORATORIES
                                               INTERNATIONAL, INC.
May 15, 2001
                                               /s/ THOMAS F. ACKERMAN
                                               --------------------------------------------
                                               Thomas F. Ackerman
                                               SR. VICE PRESIDENT AND CHIEF FINANCIAL
                                               OFFICER
</TABLE>

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