<PAGE>   1
                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                    FORM 10Q

                QUARTERLY REPORT UNDER SECTION 13 OR 15(d) OF THE
                         SECURITIES EXCHANGE ACT OF 1934

                         For Quarter Ended June 30, 2001

                           Commission File No. 1-4582


                             RALSTON PURINA COMPANY
           -----------------------------------------------------------
             (Exact name of registrant as specified in its charter)

         MISSOURI                                   43-0470580
--------------------------------------------------------------------------------
 (State of Incorporation)               (I.R.S. Employer Identification No.)

                  CHECKERBOARD SQUARE, ST. LOUIS MISSOURI 63164
 -------------------------------------------------------------------------------
               (Address of principal executive offices) (Zip Code)

                                 (314) 982-1000
          ------------------------------------------------------------
              (Registrant's telephone number, including area code)


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, and (2)
has been subject to such filing requirements for the past 90 days.

                          YES:   X          NO:
                               -----             -----


Number of shares of Ralston Purina common stock, $.10 par value, outstanding as
of the close of business on August 7, 2001: 310,622,046.




<PAGE>   2
PART I - FINANCIAL INFORMATION

                             RALSTON PURINA COMPANY
                      MANAGEMENT'S DISCUSSION AND ANALYSIS
                            OF FINANCIAL INFORMATION
                   (dollars in millions except per share data)
        ----------------------------------------------------------------

OPERATING RESULTS
Net earnings for the nine months ended June 30, 2001 were $213.3, or $.74 and
$.73 per basic and diluted share, respectively. Included in net earnings are two
unusual items which decreased net earnings by $31.9, or $.11 per basic and
diluted share, as follows: a net after-tax loss on investments of $3.2, or $.01
per basic and diluted share; and after-tax merger-related costs associated with
the pending merger between the Company and Nestle S.A. (see separate section
below), consisting primarily of adjustments to employee-related liabilities
denominated in share equivalents or tied to stock performance and transaction
costs, of $28.7 or $.10 per basic and diluted share.

The prior year nine-month net earnings of $446.9, or $1.55 and $1.53 per basic
and diluted share, respectively, include several unusual items that increased
net earnings by $127.5, or $.44 per basic and diluted share. These unusual items
include the following: an unrealized after-tax gain of $89.3, or $.31 per basic
and diluted share, representing a market value adjustment of the Company's stock
appreciation income linked securities (SAILS) debt; an after-tax gain on
investments of $7.1, or $.02 per basic and diluted share; and capital loss tax
benefits totaling $31.1, or $.11 per basic and diluted share. Net earnings for
the prior year nine months also include net earnings from discontinued
operations of $93.9, or $.33 and $.32 per basic and diluted share, respectively.
Discontinued operations represents results of the battery products business
(Energizer), which was spun off to shareholders on April 1, 2000. Pro forma
comparisons are presented below to reflect the impact of the spin-off.





<PAGE>   3

Earnings before unusual items were $245.2 for the current nine months, compared
to pro forma earnings from continuing operations before unusual items of $233.2
in the prior year. The earnings increase resulted primarily from higher segment
profitability and lower interest expense, partially offset by lower equity
earnings from the Company's investment in Interstate Bakeries Corporation (IBC).
Excluding unusual items in both periods, earnings per share were $.85 and $.84
on a basic and diluted basis, respectively, for the current nine months,
compared to pro forma earnings per share from continuing operations of $.81 and
$.80 a year ago.

The net pro forma adjustment of $7.7 in the prior year nine months represents a
reduction in interest expense due to the change in debt structure associated
with the spin-off of Energizer, net of an adjustment to income taxes to reflect
the Company's post-spin-off tax rate.

For the quarter ended June 30, 2001, net earnings were $77.5, or $.27 and $.26
per basic and diluted share, respectively, compared to $61.1, or $.21 per basic
and diluted share for the same quarter in 2000. Net earnings for the current
quarter include an after-tax gain on investments of $.8, and after-tax
merger-related costs, primarily transaction costs, of $9.5, or $.03 per basic
and diluted share.

Prior year third quarter net earnings include an unrealized after-tax gain on
SAILS debt of $2.5, or $.01 per basic and diluted share, and a net loss from
discontinued operations of $5.7, or $.02 per basic and diluted share.

Earnings before unusual items for the quarter ended June 30, 2001 were $86.2, or
$.30 and $.29 per basic and diluted share, respectively, compared to earnings
from continuing operations before unusual items of $64.3, or $.22 per basic and
diluted share, for the prior year quarter. Earnings increased primarily on
higher profitability for all three operating segments and lower interest
expense.




<PAGE>   4

RESULTS OF CONTINUING OPERATIONS
Net sales increased 2.7% in the nine months and 5.8% in the third quarter ended
June 30, 2001 on higher sales for each of the Company's operating segments. See
the following section for comments on sales changes by operating segment.

Gross profit increased $10.4 in the current nine months and $25.5 in the current
quarter. In the nine months, gross profit increases for Golden Products and
International Pet Foods were partially offset by a decrease for North American
Pet Foods. In the quarter, gross profit increased for each operating segment. As
a percentage of sales, gross profit was 58.6% in the current year nine months
compared to 59.7% a year ago. The decreased percentage reflects lower margins
for all operating segments. In the current quarter, the gross profit percentage
was 59.3% compared to 58.9% in the prior year third quarter, reflecting higher
margins for all operating segments.

Selling, general and administrative expenses increased 6.1% in the current nine
months and 1.0% in the quarter. The increase for the nine months is primarily
attributable to first quarter increases in employee-related costs, particularly
unfavorable mark-to-market adjustments on liabilities denominated in share
equivalents, and increases in International Pet Foods. Selling, general and
administrative expenses increased to 18.3% of sales in the current nine-month
period, from 17.7% a year ago. In the quarter, selling, general and
administrative expenses decreased to 18.1% of sales, compared to 19.0% in the
prior year quarter.

Advertising and promotion expense decreased 1.4% in the current nine months due
to lower expenses for North American Pet Foods and International Pet Foods,
partially offset by higher expenses for Golden Products. In the current quarter,
advertising and promotion expense increased 4.6% due to higher spending by North
American Pet Foods and Golden Products. As a percentage of sales, advertising
and promotion expense was


<PAGE>   5

20.8% and 20.7% in the current nine months and third quarter, respectively,
compared to 21.7% and 21.0% in the same periods a year ago.

Interest expense decreased to $87.9 for the current nine months from $131.1 in
the prior year primarily reflecting reduced debt levels as a result of the
spin-off of Energizer. Compared to pro forma interest expense of $116.6 for the
prior year nine months, interest expense decreased $28.7 in the current nine
months. Interest expense for the current quarter was $29.2 compared to $39.7 for
the same quarter in the prior year. The decreases in both periods were due to
lower current year debt levels as well as lower interest rates.

Other income/expense, net, was favorable $17.0 for the nine months and $7.1 for
the quarter. The favorable variance for the nine months was primarily
attributable to higher investment returns. For the quarter, the favorable
variance resulted primarily from the gain on a fixed asset disposition.

Income taxes include federal, state and foreign taxes. Excluding the unusual
items discussed above, income taxes were 35.5% of pre-tax earnings before equity
earnings in both the current year nine months and third quarter. For the prior
year nine months and third quarter, pro forma income taxes before unusual items
were 34.4% and income taxes before unusual items were 34.0%, respectively, of
pre-tax earnings before equity earnings.

OPERATING SEGMENTS
See Note 5 of the Notes to Condensed Financial Statements for a table of segment
sales and profitability for the quarters and nine months ended June 30, 2001 and
2000.

Sales for North American Pet Foods increased 1.3% in the nine months and 5.0% in
the quarter. In both periods, favorable pricing and product mix were partially
offset by an unfavorable size mix. While volumes for the nine months were
slightly lower than in

<PAGE>   6

the prior year, slightly higher volumes for the quarter contributed to the third
quarter sales increase.

Profitability for this segment increased 1.9% in the nine months as the sales
increase combined with lower advertising expenses was partially offset by higher
ingredient costs. In the quarter, profitability increased 12.8% as a result of
the sales increase, partially offset by higher promotional expenses in response
to increased competitive activity.

International Pet Foods' sales increased 3.5% in the nine months and 3.0% in the
quarter. These increases resulted primarily from volume growth in most world
areas, partially offset by decreased sales in Northern Europe due to lower
volumes and unfavorable foreign exchange.

Profitability for this segment decreased 6.0% in the nine months primarily as a
result of decreased volumes in Northern Europe, expenses associated with
expansion in the Asian market and unfavorable foreign exchange. In the quarter,
profitability increased 16.2% due primarily to the sales increase and cost
containment efforts.

Sales for Golden Products increased 13.5% in the nine months and 17.4% in the
quarter. These increases are attributable to volume increases in scooping
litter, sales of Tidy Cats Crystals Blend, the new blended scoop and
conventional litter products introduced in the current quarter, and incremental
sales of the new products introduced during the third quarter of the prior year.

Profitability for Golden Products increased 12.0% in the nine months and 36.0%
in the quarter as the sales increases were partially offset by increased
advertising and promotion expenses. Additionally, gross margins improved in the
third quarter primarily as a result of improved product mix.

<PAGE>   7

FINANCIAL CONDITION
The Company's primary source of liquidity is cash flow generated from
operations. The Company's investments in E.I. du Pont de Nemours and Company and
IBC provide additional sources of liquidity. For the nine months ended June 30,
2001, cash flow from operations was $168.9 compared to cash flow from continuing
operations of $191.0 in the nine months ended June 30, 2000. This decrease is
primarily attributable to lower cash earnings.

Working capital was $194.7 at June 30, 2001, while current liabilities exceeded
current assets by $36.7 at September 30, 2000. The working capital change is
primarily due to increased cash and cash equivalents and lower accounts payable
and accrued liabilities.

During the current and prior year nine-month periods, the Company received
proceeds from the sale of common stock investments of $117.3 and $88.6,
respectively.

In connection with the spin-off of Energizer on April 1, 2000, the Company
received during the prior year second quarter $478 from new borrowings, and then
assigned this debt to Energizer. The majority of the proceeds from the
borrowings were used by the Company to pay down its short-term debt. During the
prior year third quarter, the Company made a payment of $19.5 to Energizer,
representing a post-spin-off adjustment required in connection with the spin-off
agreement.

The Company used cash of $31.8 and $398.0 during the current and prior year nine
months, respectively, for share repurchases. As of July 20, 2001, approximately
7,562,000 shares remained under the current Board of Directors' authorization
dated May 25, 2000 for the purchase of 8,000,000 shares of RAL Stock. This
authorization is in addition to a continuing authorization permitting the
Company to acquire, from time to time and at prevailing market prices, shares of
RAL Stock that may be offered for sale by the trustee of the Company's Savings
Investment Plan as a result of investment directions from participants in the
plan.
<PAGE>   8

In connection with the merger agreement (described below), the Company has
agreed to customary restrictions on various operating matters including
restrictions on incurring debt, capital expenditures, asset dispositions,
acquisitions, share repurchases and the declaration or payment of dividends.

ACCOUNTING PRONOUNCEMENTS
The Company will implement Emerging Issues Task Force (EITF) No. 00-10,
"Accounting for Shipping and Handling Fees and Costs", in its fourth quarter of
fiscal year 2001. This consensus requires that shipping and handling costs not
be reported as a reduction of sales; however, the Company currently classifies
certain shipping costs as a reduction of sales. Implementation will result in a
reclassification from a reduction of sales to cost of products sold, which will
yield an increase in annual sales of approximately 5%. Additionally, handling
costs which the Company currently classifies as selling, general and
administrative expenses will be reclassified to cost of products sold. The
combined annual impact of these reclassifications on cost of products sold will
be an increase of approximately 17%. These reclassifications will have no impact
on net earnings.

In April 2001, the EITF of the Financial Accounting Standards Board reached
consensus on Issue No. 00-25, "Vendor Income Statement Characterization of
Consideration Paid to a Reseller of the Vendor's Products". This consensus
establishes requirements for the earnings statement classification of such
consideration as either a reduction of revenue or a cost incurred. This
consensus is effective for the Company's second quarter of fiscal year 2002 and
will result in certain reclassifications in the Company's earnings statement,
the extent of which has not yet been determined by the Company.

Issue No. 00-14, "Accounting for Certain Sales Incentives", establishes
requirements for the recognition and presentation of sales incentives such as
coupons, rebates and other discounts. In April 2001, the EITF reached a
consensus to defer the effective date for this

<PAGE>   9
guidance to the Company's second quarter of fiscal year 2002. The Company has
not completed its evaluation of the impact of EITF No. 00-14 on its financial
statements.

The Securities and Exchange Commission's Staff Accounting Bulletin (SAB) No.
101, "Revenue Recognition", was implemented by the Company with no material
impact on the Company's results of operations or financial position.

MERGER AGREEMENT
On January 16, 2001, the Company and Nestle S.A. announced that Nestle Holdings,
Inc. and the Company have entered into a definitive merger agreement. Under the
agreement, Nestle Holdings, Inc. will acquire all of the outstanding stock of
Ralston Purina for US $33.50 per share in cash. The agreement is subject to
regulatory approval, as well as other customary closing conditions. The merger
is not subject to a financing condition. While no assurances can be made that
the merger will receive the necessary regulatory approvals on acceptable terms,
the Company expects the transaction to close by December 31, 2001.


<PAGE>   10
                     RALSTON PURINA COMPANY AND SUBSIDIARIES
                       CONSOLIDATED STATEMENT OF EARNINGS
                                   (UNAUDITED)
                       (IN MILLIONS EXCEPT PER SHARE DATA)


<TABLE>
<CAPTION>

                                                                   QUARTER ENDED JUNE 30,             NINE MONTHS ENDED JUNE 30,
                                                            -------------------------------------   --------------------------------

                                                                  2001                 2000             2001             2000
                                                            ------------------  -----------------   ---------------  ---------------
<S>                                                         <C>                 <C>                 <C>              <C>


Net Sales                                                     $       707.2        $      668.3     $    2,144.6     $    2,087.4
                                                              --------------       -------------    -------------    -------------

Costs and Expenses
    Cost of products sold                                             287.9               274.5            888.8            842.0
    Selling, general and administrative                               128.0               126.8            392.0            369.4
    Advertising and promotion                                         146.6               140.2            446.0            452.4
    Interest expense                                                   29.2                39.7             87.9            131.1
    (Gain)/loss on investments, net                                    (1.2)                  -              5.1            (11.1)
    Merger-related costs                                                9.4                   -             37.2                -
    Unrealized gain on SAILS debt                                         -                (3.9)               -           (139.5)
    Other (income)/expense, net                                       (13.9)               (6.8)           (40.7)           (23.7)
                                                              --------------       -------------    -------------    -------------
                                                                      586.0               570.5          1,816.3          1,620.6
                                                              --------------       -------------    -------------    -------------

Earnings from Continuing Operations
    before Income Taxes and Equity Earnings                           121.2                97.8            328.3            466.8

Income Tax Provision                                                  (46.5)              (33.3)          (121.2)          (129.9)

Equity Earnings, Net of Taxes                                           2.8                 2.3              6.2             16.1
                                                              --------------       -------------    -------------    -------------

Earnings from Continuing Operations                                    77.5                66.8            213.3            353.0

Net Earnings/(Loss) from Discontinued Operations                          -                (5.7)               -             93.9
                                                              --------------       -------------    -------------    -------------

Net Earnings                                                  $        77.5        $       61.1     $      213.3     $      446.9
                                                              ==============       =============    =============    =============


Cash Dividends Declared per Common Share                      $           -        $          -     $       0.14     $       0.17
                                                              ==============       =============    =============    =============

Earnings Per Share
       Basic
         Earnings from continuing operations                  $        0.27        $       0.23     $       0.74     $       1.22
         Net earnings/(loss) from discontinued operations                 -               (0.02)               -             0.33
                                                              --------------       -------------    -------------    -------------
         Net Earnings                                         $        0.27        $       0.21     $       0.74     $       1.55
                                                              ==============       =============    =============    =============

       Diluted
         Earnings from continuing operations                  $        0.26        $       0.23     $       0.73     $       1.21
         Net earnings/(loss) from discontinued operations                 -               (0.02)               -             0.32
                                                              --------------       -------------    -------------    -------------
         Net Earnings                                         $        0.26        $       0.21     $       0.73     $       1.53
                                                              ==============       =============    =============    =============

</TABLE>

            See Accompanying Notes to Condensed Financial Statements.


<PAGE>   11

                     RALSTON PURINA COMPANY AND SUBSIDIARIES
                           CONSOLIDATED BALANCE SHEET
                            (CONDENSED AND UNAUDITED)
                                  (IN MILLIONS)

<TABLE>
<CAPTION>

                                                                                  JUNE 30,         SEPTEMBER 30,
                                                                              -----------------  -----------------

                                                                                    2001               2000
                                                                              -----------------  -----------------
<S>                                                                           <C>                <C>

                                   ASSETS

Current Assets
    Cash and cash equivalents                                                    $     240.0        $     112.2
    Receivables, less allowance for doubtful accounts
       of $4.0 and $4.6, respectively                                                  233.9              223.1
    Inventories
       Raw materials and supplies                                                       54.8               49.8
       Finished products                                                                87.5               80.7
    Other current assets                                                                82.7               64.1
                                                                                 ------------       ------------
       Total Current Assets                                                            698.9              529.9

Investments and Other Assets                                                         1,829.4            1,797.1

Property at Cost                                                                     1,271.3            1,224.8
    Accumulated depreciation                                                           641.3              608.2
                                                                                 ------------       ------------
                                                                                       630.0              616.6

                                                                                 ------------       ------------
           Total                                                                 $   3,158.3        $   2,943.6
                                                                                 ============       ============


                     LIABILITIES AND SHAREHOLDERS EQUITY

Current Liabilities
    Current maturities of long-term debt                                         $       7.1        $       4.6
    Notes payable                                                                      164.7              158.4
    Accounts payable                                                                   112.4              140.9
    Other current liabilities                                                          220.0              262.7
                                                                                 ------------       ------------
       Total Current Liabilities                                                       504.2              566.6

Long-Term Debt                                                                       1,242.6            1,245.3

Deferred Income Taxes                                                                  276.8              267.8

Other Liabilities                                                                      455.8              425.3

Shareholders Equity
    Preferred stock                                                                        -                  -
    Common stock                                                                        32.9               32.9
    Capital in excess of par value                                                     209.4              193.2
    Retained earnings                                                                1,446.4            1,293.5
    Common stock in treasury, at cost                                                 (438.3)            (477.0)
    Unearned portion of restricted stock                                               (29.0)              (0.7)
    Value of common stock held in Grantor Trust                                       (378.0)            (372.0)

       Cumulative translation adjustment                                               (26.1)             (18.7)
       Net unrealized holding loss on available-for-sale securities                   (133.1)            (208.5)
       Net deferred hedging loss                                                        (1.2)                 -
       Minimum pension liability                                                        (4.1)              (4.1)
                                                                                 ------------       ------------
    Accumulated other comprehensive loss                                              (164.5)            (231.3)
                                                                                 ------------       ------------
       Total Shareholders Equity                                                       678.9              438.6

                                                                                 ------------       ------------
           Total                                                                 $   3,158.3        $   2,943.6
                                                                                 ============       ============

</TABLE>

            See Accompanying Notes to Condensed Financial Statements.





<PAGE>   12

                     RALSTON PURINA COMPANY AND SUBSIDIARIES
                      CONSOLIDATED STATEMENT OF CASH FLOWS
                            (CONDENSED AND UNAUDITED)
                                  (IN MILLIONS)



<TABLE>
<CAPTION>

                                                                                        NINE MONTHS ENDED JUNE 30,
                                                                                  -------------------------------------

                                                                                         2001                2000
                                                                                  ------------------   ----------------
<S>                                                                              <C>                   <C>

Cash Flow from Operations
    Net earnings                                                                          $ 213.3             $ 446.9
    Net earnings from discontinued operations                                                   -               (93.9)
    Unrealized gain on SAILS debt                                                               -              (139.5)
    Loss (gain) on investments, net                                                           5.1               (11.1)
    IBC equity earnings, pre-tax                                                             (8.1)              (22.1)
    Non-cash items included in income                                                        36.8               101.9
    Changes in assets and liabilities used in operations                                    (79.5)              (78.8)
    Other, net                                                                                1.3               (12.4)
                                                                                     -------------       -------------
       Cash flow from continuing operations                                                 168.9               191.0
       Cash flow from discontinued operations                                                   -               214.4
                                                                                     -------------       -------------
          Net cash flow from operations                                                     168.9               405.4
                                                                                     -------------       -------------

Cash Flow from Investing Activities
    Property additions, net                                                                 (74.1)              (78.2)
    Proceeds from the sale of investments in common stock                                   117.3                88.6
    Other, net                                                                              (25.2)              (25.0)
                                                                                     -------------       -------------
       Cash from (used by) investing activities - continuing operations                      18.0               (14.6)
       Cash used by investing activities - discontinued operations                              -                (1.6)
                                                                                     -------------       -------------
          Net cash from (used by) investing activities                                       18.0               (16.2)
                                                                                     -------------       -------------

Cash Flow from Financing Activities
       Net cash proceeds from issuance of (payment of) debt                                  10.6              (411.6)
       Dividends paid                                                                       (60.2)              (77.8)
       Treasury stock purchases                                                             (31.8)             (398.0)
       Other, net                                                                            22.7                18.6
                                                                                     -------------       -------------
          Cash used by financing activities - continuing operations                         (58.7)             (868.8)
          Cash from financing activities - discontinued operations                              -               478.1
                                                                                     -------------       -------------
            Net cash used by financing activities                                           (58.7)             (390.7)
                                                                                     -------------       -------------

Effect of Exchange Rate Changes on Cash                                                      (0.4)               (1.4)
                                                                                     -------------       -------------

Net Increase (Decrease) in Cash and Cash Equivalents                                        127.8                (2.9)

Cash and Cash Equivalents, Beginning of Period                                              112.2                56.6

                                                                                     -------------       -------------
Cash and Cash Equivalents, End of Period                                                  $ 240.0              $ 53.7
                                                                                     =============       =============

</TABLE>

            See Accompanying Notes to Condensed Financial Statements.

<PAGE>   13
                     RALSTON PURINA COMPANY AND SUBSIDIARIES
                     NOTES TO CONDENSED FINANCIAL STATEMENTS
                                  JUNE 30, 2001
                   (Dollars in millions except per share data)

NOTE 1 - The accompanying unaudited financial statements have been prepared in
accordance with the instructions for Form 10-Q and do not include all of the
information and footnotes required by generally accepted accounting principles
for complete financial statements. In the opinion of management, all adjustments
considered necessary for a fair presentation have been included. Operating
results for any quarter are not necessarily indicative of the results for any
other quarter or for the full year. These statements should be read in
conjunction with the financial statements and notes thereto included in the
Ralston Purina Company (the Company) Annual Report to Shareholders for the year
ended September 30, 2000.

NOTE 2 - During the nine months ended June 30, 2001, the Company sold its
remaining investment in Conoco, Inc. (Conoco) B common stock for $117.3 and
recognized a gain of $3.7 after tax, or $5.7 pre-tax. On a per share basis, this
gain was $.01 per basic and diluted share. For the quarter ended June 30, 2001,
the Company recognized an after-tax and pre-tax gain of $0.8 and $1.2,
respectively, on the sale of Conoco B common stock. The cost basis of the shares
sold was determined using the average cost method.

At March 31, 2001, the Company determined that the reduction in the value of its
investment in Heska common stock was other than temporary and, accordingly,
recorded an after-tax write-down of $6.9, or $10.8 pre-tax. The amount of the
write-down was determined based on the market value of Heska common stock at
March 31, 2001. On a per share basis, this write-down was $.02 per basic and
diluted share for the nine months ended June 30, 2001.

During the nine months ended June 30, 2000, the Company sold a portion of its
investment in E.I. du Pont de Nemours and Company (DuPont) common stock for
$88.6 and recorded an after-tax gain of $7.1, or $.02 per basic and diluted
share. On a pre-tax basis, this gain was $11.1. The cost basis of the shares
sold was determined using the average cost method.

At June 30, 2001, the Company held 1.2 million shares of Heska common stock,
14.8 million shares of DuPont common stock and 14.8 million shares of Interstate
Bakeries Corporation common stock.

NOTE 3 - On January 16, 2001, the Company and Nestle S.A. announced that Nestle
Holdings, Inc. and the Company have entered into a definitive merger agreement.
Under the agreement, Nestle Holdings, Inc. will acquire all of the outstanding
stock of Ralston Purina for US $33.50 per share in cash. The agreement is
subject to regulatory approval, as well as other customary closing conditions.
The merger is not subject to a financing condition. In connection with the
merger agreement, the Company has agreed to customary restrictions on various
operating matters including restrictions on incurring debt, capital
expenditures, asset dispositions, acquisitions, share repurchases and the
declaration or payment of dividends. While no assurances can be made that the
merger will receive the necessary regulatory approvals on acceptable terms,
the Company expects the transaction to close by December 31, 2001.

The Company recorded after-tax costs of $28.7 and $9.5 during the nine months
and quarter ended June 30, 2001, respectively, related to the pending merger.
These costs primarily include registration, legal and financial advisor fees
and, additionally for the nine months, adjustments to



<PAGE>   14
                     RALSTON PURINA COMPANY AND SUBSIDIARIES
                     NOTES TO CONDENSED FINANCIAL STATEMENTS
                                  JUNE 30, 2001
                   (Dollars in millions except per share data)


employee-related liabilities denominated in share equivalents or tied to stock
performance. On a per share basis, these costs were $.10 per basic and diluted
share for the nine months and $.03 per basic and diluted share for the quarter.
On a pre-tax basis, these costs were $37.2 and $9.4 for the nine months and
quarter ended June 30, 2001, respectively.

NOTE 4 - On October 1, 2000, the Company implemented, on a prospective basis,
Statement of Financial Accounting Standards (SFAS) No. 133, "Accounting for
Derivative Instruments and Hedging Activities," as amended by SFAS No. 137 and
SFAS No. 138 (collectively, the Statement). This Statement requires all
derivatives to be recognized in the statement of financial position at fair
value, with changes in the fair value of derivative instruments to be recorded
in current earnings or deferred in other comprehensive income, depending on
whether a derivative is designated as and is effective as a hedge and on the
type of hedging transaction. In accordance with the provisions of SFAS No. 133,
upon implementation the Company reclassified previously deferred hedging losses
on designated cash flow hedges of $10.8, which are net of taxes of $6.0, from
current assets to accumulated other comprehensive loss.

The Company uses derivative instruments, primarily foreign exchange forward
contracts and commodity futures contracts, to manage certain of its foreign
exchange rate and commodity price risks. The terms of such instruments, and the
hedging transactions to which they relate, generally do not exceed 12 months.
Company policy allows for the use of derivative financial instruments only for
identifiable exposures and, therefore, the Company does not enter into
derivative instruments for trading purposes where the objective is to generate
profits.

With respect to foreign exchange rate risk, the Company's objective is to limit
potential losses in earnings or cash flows from adverse foreign currency
exchange rate movements related to foreign currency transactions. The Company's
foreign currency exposures arise from transactions denominated in a currency
other than an entity's functional currency, primarily anticipated purchases of
raw materials and sales of finished product, and the settlement of receivables
and payables. The primary currencies to which the Company's foreign affiliates
are exposed include the U.S. dollar and the euro.

The Company also uses commodity futures contracts with the objective of reducing
commodity price risks related to future raw material requirements for
commodities such as corn, wheat, soybean meal and various other high protein
ingredient meals. Commodity price risks arise from price volatility due to
factors such as weather conditions, government regulations, economic climate and
other unforeseen circumstances.

Generally, the Company applies hedge accounting as allowed by the Statement.
However, at times the Company may enter into derivatives which economically
hedge certain of its risks even though hedge accounting is not allowed by the
Statement or is not applied by the Company. For derivatives where hedge
accounting is used, the Company formally designates the derivative as either 1)
a fair value hedge of a recognized asset or liability or unrecognized firm
commitment; 2) a cash flow hedge of an anticipated transaction; or 3) a foreign
currency fair value and/or cash flow hedge. The Company also documents the
designated hedging relationship upon entering into the derivative, including
identification of the hedging instrument and the hedged item or transaction,
strategy and risk management objective for undertaking the hedge, and the nature
of




<PAGE>   15
                     RALSTON PURINA COMPANY AND SUBSIDIARIES
                     NOTES TO CONDENSED FINANCIAL STATEMENTS
                                  JUNE 30, 2001
                   (Dollars in millions except per share data)


the risk being hedged. Furthermore, each derivative is assessed for hedge
effectiveness both at the inception of the hedging relationship and on a
quarterly basis, for as long as the derivative is outstanding. Hedge accounting
is only applied when the derivative is deemed to be highly effective at
offsetting changes in fair values or anticipated cash flows of the hedged item
or transaction. For hedged forecasted transactions, hedge accounting is
discontinued if the forecasted transaction is no longer intended to occur, and
any previously deferred hedging gains or losses would be recorded to earnings
immediately. Earnings impacts for all designated hedges are recorded in the
Consolidated Statement of Earnings generally on the same line item as the gain
or loss on the item being hedged.

The Company records all derivatives at fair value as assets or liabilities in
the Consolidated Balance Sheet, with classification as current or long-term
depending on the duration of the instrument. For fair value hedges, the
effective and ineffective portions of the change in fair value of the
derivative, along with the gain or loss on the hedged item, are recorded in
earnings as incurred. For cash flow hedges, the effective portion of the change
in fair value of the derivative is deferred in accumulated other comprehensive
income in the Consolidated Balance Sheet until the transaction is reflected in
the Consolidated Statement of Earnings, at which time any deferred hedging gains
or losses are recorded in earnings. The ineffective portion of the change in the
fair value of a derivative used as a cash flow hedge is recorded in earnings as
incurred.

Hedge ineffectiveness and the portion of derivative gains or losses excluded
from assessments of hedge effectiveness related to the Company's outstanding
cash flow hedges are recorded to earnings. During the nine months and quarter
ended June 30, 2001, this amount was a gain of $0.4 and $0.6, respectively. At
June 30, 2001, the net deferred hedging loss in Accumulated Other Comprehensive
Income was $1.2. This entire deferred loss is expected to be recognized in
earnings during the twelve months ended June 30, 2002, at the time the
underlying hedged transactions are recognized in the earnings statement. See
Note 9 below for comprehensive income for the Company's cash flow hedging
activities for the quarter and nine months ended June 30, 2001.

NOTE 5 - Segment sales and profitability for the quarters and nine months ended
June 30, 2001 and 2000 are as follows:

<TABLE>
<CAPTION>
                                       Quarter ended June 30,             Nine Months ended June 30,
                                       ---------------------              -------------------------
NET SALES                            2001               2000               2001                2000
                                     ----               ----               ----                ----
<S>                                 <C>               <C>               <C>                 <C>
North American Pet Foods.......     $  518.3          $  493.4          $  1,591.5          $  1,570.7
International Pet Foods........        117.3             113.9               344.1               332.6
Golden Products ...............         71.6              61.0               209.0               184.1
                                    --------          --------          ----------          ----------
    TOTAL .....................     $  707.2          $  668.3          $  2,144.6          $  2,087.4
                                    ========          ========          ==========          ==========
</TABLE>



<PAGE>   16
                     RALSTON PURINA COMPANY AND SUBSIDIARIES
                     NOTES TO CONDENSED FINANCIAL STATEMENTS
                                  JUNE 30, 2001
                   (Dollars in millions except per share data)


<TABLE>
<CAPTION>
                                                    Quarter ended June 30,        Nine Months ended June 30,
                                                    ---------------------         -------------------------
PROFITABILITY                                       2001             2000            2001           2000
                                                    ----             ----            ----           ----
<S>                                              <C>             <C>             <C>             <C>

North American Pet Foods ...............         $  123.5        $  109.5        $  363.2        $  356.5
International Pet Foods ................             12.2            10.5            32.9            35.0
Golden Products ........................             15.5            11.4            46.6            41.6
                                                 --------        --------        --------        --------
    TOTAL SEGMENT PROFITABILITY ........            151.2           131.4           442.7           433.1

General corporate income/(expenses).....             11.8             6.6            28.8            27.4
Amortization of goodwill and other
    intangible assets ..................             (4.4)           (4.4)          (13.0)          (13.2)
Unusual items (a) ......................             (8.2)            3.9           (42.3)          150.6
Interest expense .......................            (29.2)          (39.7)          (87.9)         (131.1)
                                                 --------        --------        --------        --------
     EARNINGS FROM CONTINUING OPERATIONS
        BEFORE INCOME TAXES AND EQUITY
        EARNINGS .......................         $  121.2        $   97.8        $  328.3        $  466.8
                                                 ========        ========        ========        ========
</TABLE>


         (a)      Includes gain/loss on investments for the quarter ended June
                  30, 2001 and for the nine months ended June 30, 2001 and 2000;
                  merger-related costs for the quarter and nine months ended
                  June 30, 2001; and an unrealized gain on SAILS debt for the
                  quarter and nine months ended June 30, 2000.

NOTE 6 - During the nine months and quarter ended June 30, 2000, the Company
recorded an unrealized after-tax gain of $89.3 and $2.5, respectively, or $139.5
and $3.9 pre-tax, representing a market value adjustment of the Company's stock
appreciation income linked securities (SAILS) debt, which matured on August 1,
2000. On a per share basis, this gain was $.31 per basic and diluted share for
the nine months and $.01 per basic and diluted share for the quarter.

NOTE 7 - During the nine months ended June 30, 2000, the Company recorded
capital loss tax benefits totaling $31.1, or $.11 per basic and diluted share,
related to the sale and reorganization of two of the Company's subsidiaries.

NOTE 8 - On April 1, 2000, the Company completed the tax-free spin-off to
shareholders of its Battery Products business (Energizer). This segment is
accounted for as a discontinued operation in the prior year financial statements
and related notes.


<PAGE>   17

                     RALSTON PURINA COMPANY AND SUBSIDIARIES
                     NOTES TO CONDENSED FINANCIAL STATEMENTS
                                  JUNE 30, 2001
                   (Dollars in millions except per share data)


NOTE 9 - The components of total comprehensive income for the quarters and nine
months ended June 30, 2001 and 2000 are as follows:

<TABLE>
<CAPTION>
                                                                 Quarter Ended June 30,        Nine Months Ended June 30,
                                                                 ----------------------        --------------------------
                                                                   2001           2000            2001            2000
                                                                   ----           ----            ----            ----
<S>                                                             <C>             <C>            <C>             <C>
Net Earnings                                                    $   77.5        $  61.1        $  213.3        $  446.9
                                                                --------        -------        --------        --------
  Other Comprehensive Income, Net of Tax
    Foreign currency translation adjustments                        (0.7)          (2.2)           (7.4)           (4.6)
    Effect of Energizer spin-off on cumulative
      translation adjustment                                          --           84.6              --            84.6
    Unrealized gains/(losses) on available-for-sale
      securities                                                    71.4          (95.4)           72.2          (162.2)
        Reclassification adjustment due to sale of
         available-for-sale securities                              (0.8)            --            (3.7)           (7.1)

        Reclassification adjustment due to write-down
         of available-for-sale securities                             --             --             6.9              --
    Transition adjustment due to change in accounting
         for derivative instruments and hedging
         activities                                                   --             --           (10.8)             --
    Additional gain/(loss) deferrals on qualifying cash
         flow hedges                                                 1.3             --            (0.6)             --
        Reclassification adjustment for cash flow
         hedging losses realized in net income                       1.5             --            10.2              --
                                                                --------        -------        --------        --------

Total Other Comprehensive Income/(Loss)                             72.7          (13.0)           66.8           (89.3)
                                                                --------        -------        --------        --------
              Total Comprehensive Income                        $  150.2        $  48.1        $  280.1        $  357.6
                                                                ========        =======        ========        ========
</TABLE>

NOTE 10 - Other (income)/expense, net, for the nine months ended June 30, 2001
and 2000, consists of the following:

<TABLE>
<CAPTION>
                                                               Nine Months ended June 30,
                                                               --------------------------
                                                                 2001              2000
                                                                 ----              ----
<S>                                                           <C>               <C>
          Dividends on available-for-sale securities           $ (16.8)         $  (20.2)
          Return on other investments                            (11.6)             (3.2)
          Investment income                                       (8.5)             (3.5)
          Miscellaneous (income)/expense                          (3.8)              3.2
                                                              --------          --------
                                                              $  (40.7)          $ (23.7)
                                                              ========          ========
</TABLE>




<PAGE>   18

                     RALSTON PURINA COMPANY AND SUBSIDIARIES
                     NOTES TO CONDENSED FINANCIAL STATEMENTS
                                  JUNE 30, 2001
                   (Dollars in millions except per share data)


NOTE 11 - The following table sets forth the computation of basic and diluted
earnings per share for the quarters and nine months ended June 30, 2001 and
2000.

<TABLE>
<CAPTION>
                                                                  Quarter ended June 30,       Nine Months Ended June 30,
                                                                  ----------------------       --------------------------
                                                                    2001           2000            2001           2000
                                                                    ----           ----            ----           ----
<S>                                                              <C>            <C>             <C>            <C>
Numerator:
    Earnings from continuing operations                            $ 77.5         $ 66.8          $ 213.3        $ 353.0
    Net earnings/(loss) from discontinued operations                    -           (5.7)               -           93.9
                                                                 --------       --------        ---------      ---------
    Net Earnings                                                   $ 77.5         $ 61.1          $ 213.3        $ 446.9
                                                                 --------       --------        ---------      ---------

Denominator:
    Denominator for basic earnings per share -
       weighted average shares *                                    286.7          285.9            286.5          288.7

    Effect of dilutive securities -- stock options                    6.5            2.3              5.9            3.1
                               -- restricted stock                    0.2              -              0.1              -
                                                                 --------       --------        ---------      ---------

    Denominator for diluted earnings per share -
       adjusted weighted average shares and
       assumed conversions                                          293.4          288.2            292.5          291.8
                                                                 ========       ========        =========      =========

Basic earnings per share:
  Earnings from continuing operations                              $ 0.27         $ 0.23          $  0.74        $  1.22
  Net earnings/(loss) from discontinued operations                      -          (0.02)               -           0.33

                                                                 --------       --------        ---------      ---------
  Net earnings                                                     $ 0.27         $ 0.21          $  0.74        $  1.55
                                                                 ========       ========        =========      =========


Diluted earnings per share:
  Earnings from continuing operations                              $ 0.26         $ 0.23          $  0.73        $  1.21
  Net earnings/(loss) from discontinued operations                      -          (0.02)               -           0.32
                                                                 --------       --------        ---------      ---------
  Net earnings                                                     $ 0.26         $ 0.21          $  0.73        $  1.53
                                                                 ========       ========        =========      =========
</TABLE>


* Weighted average shares used for the computation of basic earnings per share
exclude 21,964,000 and 21,694,000 shares of common stock held by the Company's
Grantor Trust at June 30, 2001 and 2000, respectively.

NOTE 12 - At June 30, 2001, there were 287,995,000 shares of common stock
outstanding, exclusive of 18,621,000 shares held in treasury and 21,964,000
Grantor Trust shares. At September 30, 2000, there were 286,358,000 shares of
common stock outstanding, exclusive of 20,461,000 shares held in treasury and
21,761,000 Grantor Trust shares.


<PAGE>   19

                     RALSTON PURINA COMPANY AND SUBSIDIARIES
                     NOTES TO CONDENSED FINANCIAL STATEMENTS
                                  JUNE 30, 2001
                   (Dollars in millions except per share data)


NOTE 13 - Investments and Other Assets consist of the following:

<TABLE>
<CAPTION>
                                                               June 30,        September 30,
                                                                 2001             2000
                                                                 ----             ----
<S>                                                          <C>               <C>
           Available-for-sale securities                     $     721.7       $     726.3
           Deferred charges and other assets                     1,107.7           1,070.8
                                                             -----------       -----------
                                                               $ 1,829.4         $ 1,797.1
                                                             ===========       ===========
</TABLE>

NOTE 14 - Available-for-sale securities at June 30, 2001 and September 30, 2000
consist primarily of shares of E.I. du Pont de Nemours and Company (DuPont)
common stock. Available-for-sale securities are carried at fair value, based on
quoted market prices. The difference between fair value and cost basis of these
securities, net of tax, is shown as a separate component within Accumulated
Other Comprehensive Income in the shareholders equity section of the
Consolidated Balance Sheet. The table below shows the aggregate fair value,
gross unrealized holding loss, tax benefit, and net unrealized holding loss for
these securities as of June 30, 2001 and September 30, 2000. The changes in net
unrealized holding loss, net of tax, for the quarters and nine-month periods
ended June 30, 2001 and 2000 are included as a component of Other Comprehensive
Income as shown in Note 9, above.


<TABLE>
<CAPTION>
                                 Aggregate         Gross Unrealized                         Net Unrealized
                                 Fair Value          Holding Loss         Tax Benefit        Holding Loss
                                 ----------          ------------         -----------        ------------
<S>                              <C>               <C>                    <C>               <C>
June 30, 2001                     $ 721.7               $ 208.0              $  74.9            $ 133.1
September 30, 2000                $ 726.3               $ 325.8              $ 117.3            $ 208.5
</TABLE>


NOTE 15 - During the first quarter of fiscal 2001, the Company issued 1.2
million shares of restricted common stock of the Company with a five-year
vesting period. Upon issuance of the restricted shares, unearned compensation
equivalent to the market value at the date of grant was charged to Shareholders
Equity and will be amortized to expense over the five-year vesting period. The
lapsing of restrictions on these shares will be accelerated in certain
circumstances, one of which is a change in control of the Company.

<PAGE>   20

PART II - OTHER INFORMATION

There is no information required to be reported under any items except those
indicated below.

Item 1. Legal Proceedings

The Company previously disclosed an action entitled Hack, et al. v. Banks, et
al. This action was voluntarily dismissed without prejudice by the plaintiffs on
June 13, 2001.


Item 4. Submission of Matter to a Vote of Security Holders

On May 21, 2001 the Company held a special meeting of shareholders to consider
and vote upon the proposal to approve the Agreement and Plan of Merger, dated as
of January 15, 2001, among the Company, Nestle Holdings, Inc. and a wholly owned
subsidiary of Nestle Holdings, Inc., pursuant to which the subsidiary will be
merged into the Company and each share of common stock of the Company
outstanding immediately prior to the merger will be converted into the right to
receive $33.50 in cash.

The number of shares voting for and against the proposal, as well as the number
of abstentions with respect thereto, is as follows:

VOTES             VOTES            VOTES
FOR               AGAINST          ABSTAINED

231,165,553       5,087,273        1,076,214


Item 6. Exhibits and Reports on Form 8-K

                  (a)      Exhibits filed with this Report:

                           (10)(i) Resolution dated May 16, 2001 amending the
                           Trust Agreement

                           (10)(ii) Executive Group Personal Excess Liability
                           Insurance Summary

                           (10)(iii) Resolution dated January 15, 2001 amending
                           the Bonus Plans and Deferred Compensation Plans

                  (b)      Reports on Form 8-K

                       A Current Report on Form 8-K was filed by the Company on
                       May 21, 2001 to disclose that the proposed merger with
                       Nestle Holdings, Inc. had received the requisite
                       shareholder approval at the May 21, 2001 special meeting
                       of the Company's shareholders.



<PAGE>   21
                                   SIGNATURES

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.



                                RALSTON PURINA COMPANY
                                ----------------------
                                Registrant


                                By: /s/ James R. Elsesser
                                   -----------------------------------------
                                   James R. Elsesser
                                   Vice President, Chief Financial Officer
                                   and Treasurer



Date:   August 9, 2001



<PAGE>   22

EXHIBIT INDEX


Exhibits


EX-10                      Material Contracts

                           (10)(i) Resolution dated May 16, 2001 amending the
                           Trust Agreement

                           (10)(ii) Executive Group Personal Excess Liability
                           Insurance Summary

                           (10)(iii) Resolution dated January 15, 2001 amending
                           the Bonus Plans and Deferred Compensation Plans