<PAGE>
                                                                   Exhibit 10.10


                       THIRD AMENDMENT TO CREDIT AGREEMENT

         This Third Amendment to Credit Agreement (the "Second Amendment") is
made as of this 20 day of June, 2002 by and among

         PETSMART, INC., a Delaware corporation, having a principal place of
         business at 19601 North 27th Avenue, Phoenix, Arizona 85027, as Lead
         Borrower for the Borrowers, being


                  said PETSMART, INC., and

                  PETSMART DIRECT, INC., a New York corporation, having a
                  principal place of business at 1989 Transit Way, Brockport,
                  New York 14420;

                  PETSMART STORE SUPPORT GROUP, INC., a Delaware corporation,
                  having a principal place of business at 19601 North 27th
                  Avenue, Phoenix, Arizona 85027;

                  PETSMART.COM., INC., a Delaware corporation, having a
                  principal place of business at 19601 North 27th Avenue,
                  Phoenix Arizona 85027; and

                  PET CATALOG, LLC, a Delaware limited liability company, having
                  a principal place of business at 19601 North 27th Avenue,
                  Phoenix, Arizona 85027

         each of the Lenders party to the Credit Agreement (defined below)
         (together with each of their successors and assigns, referred to
         individually as a "Lender" and collectively as the "Lenders"), and

         FLEET NATIONAL BANK, as Issuing Bank, a national banking association
         having a place of business at 100 Federal Street, Boston, Massachusetts
         02110; and

         FLEET RETAIL FINANCE INC., as Administrative Agent and Collateral Agent
         for the Lenders, a Delaware corporation, having its principal place of
         business at 40 Broad Street, Boston, Massachusetts 02109; and

         CONGRESS FINANCIAL CORPORATION (WESTERN), as Co-Agent.

In consideration of the mutual covenants herein contained and benefits to be
derived herefrom.

                               W I T N E S S E T H

         A.       Reference is made to the Credit Agreement (as amended and in
effect, the "Credit Agreement") dated as of April 30, 2001 by and among the Lead
Borrower, the Borrowers, the Lenders, the Issuing Bank, the Agents, and the
Co-Agent.

         B.       The parties to the Credit Agreement desire to modify and amend
certain provisions of the Credit Agreement, as provided herein.



                                       1.
<PAGE>
         Accordingly, the parties hereto agree as follows:

         1.       Definitions. Capitalized terms used herein and not otherwise
defined herein shall have the meanings assigned to such terms in the Credit
Agreement.

         2.       Amendments to Article I of the Credit Agreement. The
provisions of Article I of the Credit Agreement are hereby amended as follows:

         a.       The definition of "Bonds" is hereby deleted in its entirety
                  and the following substituted in its stead:

                  "Bonds" means any unsecured Indebtedness for borrowed money
                  permitted pursuant to this Agreement.

         b.       The definition of "Cash Control Event" is hereby deleted in
                  its entirety and the following substituted in its stead:

                  "Cash Control Event" means that Excess Availability is less
                  than $40,000,000. For purposes of Section 2.21(h) hereof, the
                  occurrence of a Cash Control Event shall be deemed continuing
                  notwithstanding that Excess Availability may thereafter exceed
                  the amount set forth in the preceding sentence unless and
                  until Excess Availability exceeds such amount for sixty (60)
                  consecutive days, in which case a Cash Control Event shall no
                  longer be deemed to be continuing for purposes of Section
                  2.21(h) hereof, provided that a Cash Control Event shall be
                  deemed continuing (even if Excess Availability exceeds the
                  required amounts for sixty consecutive days) if a Cash Control
                  Event has occurred and been discontinued on three (3)
                  occasions in any twelve month period.

         c.       The definition of "Maturity Date" is hereby deleted in its
                  entirety and the following substituted in its stead:

                  "Maturity Date" means April 30, 2006.

         d.       The definition of "Payment Conditions" is hereby deleted in
                  its entirety and the following substituted in its stead:

                  "Payment Conditions" means, at the time of determination, that
                  (a) no Default or Event of Default then exists or would arise
                  as a result of the making of the subject payment, and (b)
                  prior to, and immediately after giving effect to, the subject
                  payment, and on a pro forma twelve months basis thereafter,
                  Excess Availability shall be equal to or greater than
                  $40,000,000.00.

         3.       Amendments to Article II of the Credit Agreement. The
provisions of Article II of the Credit Agreement are hereby amended as follows:

         a.       The provisions of Section 2.01(a)(i) of the Credit Agreement
                  are hereby amended by deleting the number "$250,000,000"
                  appearing therein and substituting the number "$200,000,000"
                  in its stead.

                                       2.
<PAGE>
         b.       The provisions of Section 2.05(b) of the Credit Agreement are
                  hereby amended by deleting the number "$250,000,000" appearing
                  therein and substituting the number "$200,000,000" in its
                  stead.

         4.       Amendments to Article V of the Credit Agreement. The
provisions of Article V of the Credit Agreement are hereby amended as follows:

         a.       The provisions of Section 5.01(c) of the Credit Agreement are
                  hereby amended by adding the following at the beginning
                  thereof:

                  at any time that a Cash Control Event exists,

         b.       The provisions of Section 5.01(f) of the Credit Agreement are
                  hereby deleted in their entirety and the following substituted
                  in their stead:

                  (f) within five (5) days after the end of each month, a
                  certificate in the form of Exhibit D (a "Borrowing Base
                  Certificate") showing the Borrowing Base as of the close of
                  business on the last day of the immediately preceding month,
                  each such Certificate to be certified as complete and correct
                  on behalf of the Borrowers by a Financial Officer of the Lead
                  Borrower, provided, however, if and so long as a Cash Control
                  Event exists, such Borrowing Base Certificate (showing the
                  Borrowing Base as of the close of business on the last day of
                  the immediately preceding week) shall be furnished weekly on
                  Wednesday of each week;

         c.       The provisions of Section 5.01(j) of the Credit Agreement by
                  deleting the number "$5,000,000" and substituting the number
                  "$20,000,000" in its stead.

         d.       The provisions of Section 5.03 of the Credit Agreement are
                  hereby amended by adding the following at the end of clause
                  (ii) thereof:

                  provided that, notwithstanding the foregoing, the Lead
                  Borrower shall only be obligated to furnish a store listing
                  quarterly within 45 days of the end of each fiscal quarter;

         e.       The provisions of Section 5.09(b) of the Credit Agreement are
                  hereby deleted in their entirety and the following substituted
                  in their stead:

                  (b) Each Loan Party will, and will cause each of the
                  Subsidiaries to, from time to time upon the request of the
                  Collateral Agent or the Required Lenders through the
                  Administrative Agent, permit any Agent or professionals
                  (including investment bankers, consultants, accountants,
                  lawyers and appraisers) retained by the Agents, upon
                  reasonable prior notice and during normal business hours, to
                  conduct appraisals, commercial finance examinations and other
                  evaluations, including, without limitation, of (i) the
                  Borrowers' practices in the computation of the Borrowing Base
                  and (ii) the assets included in the Borrowing Base and related
                  financial information such as, but not limited to, sales,
                  gross margins, payables, accruals and reserves, and pay the
                  reasonable fees and expenses of the Agents or such
                  professionals with respect to such evaluations and appraisals,
                  provided that


                                       3.
<PAGE>
                  as long as a Default has not occurred and is continuing, in
                  each fiscal year commencing with the Borrowers' fiscal year
                  beginning February, 2002, as long as average Excess
                  Availability for the last six months of the immediately
                  preceding fiscal year was equal to or greater than (A)
                  $80,000,000.00, the Borrowers shall not be required to pay for
                  more than one commercial finance examination and one inventory
                  appraisal in the then current fiscal year, or (B)
                  $40,000,000.00 (but less than $80,000,000.00), the Borrowers
                  shall not be required to pay for more than three commercial
                  finance examinations and three inventory appraisals in the
                  then current fiscal year provided that if the average Excess
                  Availability for any thirty day period in any fiscal year is
                  equal to or less than $40,000,000.00, the Borrowers shall be
                  required to pay for all commercial finance examinations and
                  appraisals undertaken during such fiscal year.

         5.       Amendments to Article VI of the Credit Agreement. The
provisions of Article VI of the Credit Agreement are hereby amended as follows:

         a.       The provisions of Section 6.01(a)(v) are hereby deleted in
                  their entirety and the following substituted in their stead:

                  (v) Indebtedness of any Loan Party to finance the acquisition,
                  construction or improvement of any fixed or capital assets or
                  software, including Capital Lease Obligations and any
                  Indebtedness assumed in connection with the acquisition of any
                  such assets or secured by a Lien on any such assets prior to
                  the acquisition thereof, and extensions, renewals and
                  replacements of any such Indebtedness that do not increase the
                  outstanding principal amount thereof or result in an earlier
                  maturity date or decreased weighted average life thereof,
                  provided that the aggregate principal amount of Indebtedness
                  permitted by this clause (v) shall not exceed $50,000,000.00
                  at any time outstanding;

         b.       The provisions of Section 6.01(a)(ix) are hereby deleted in
                  their entirety and the following substituted in their stead:

                  (ix) other unsecured Indebtedness or subordinated
                  Indebtedness, provided that the terms of such Indebtedness are
                  customary for the applicable type of financing;

         c.       The provisions of Section 6.01(b) are hereby deleted in their
                  entirety.

         d.       The provisions of Section 6.04(d) are hereby deleted in their
                  entirety and the following substituted in their stead:

                  (d) Guarantees constituting Indebtedness permitted by Section
                  6.01, provided that such Guarantees by the Borrowers, other
                  than Guarantees of Indebtedness permitted under Section
                  6.01(a)(ix), shall not exceed $20,000,000.00 in the aggregate
                  at any time outstanding;

         e.       The provisions of Section 6.04(f) are hereby deleted in their
                  entirety and the following substituted in their stead:



                                       4.
<PAGE>
                  (f) loans or advances to employees for the purpose of travel,
                  entertainment or relocation in the ordinary course of business
                  in an amount not to exceed $1,000,000.00 to any employee or
                  $7,500,000.00 in the aggregate at any time outstanding;

         f.       The provisions of Section 6.04(g) are hereby deleted in their
                  entirety and the following substituted in their stead:

                  (g) acquisitions of the capital stock or assets of any other
                  Person, provided that (i) no Cash Control Event exists
                  immediately prior to, or after giving effect to, the
                  acquisition, and (ii) no Default or Event of Default exists
                  immediately prior to, or after giving effect to, the
                  acquisition, and (iii) the provisions of Section 5.12 are
                  satisfied, or if the transaction is an asset acquisition,
                  reasonably promptly after such acquisition, the applicable
                  Loan Parties shall have executed such documents and agreements
                  as the Collateral Agent shall have reasonably requested in
                  order to create and perfect the Collateral Agent's Lien on the
                  assets so acquired.

         g.       The provisions of Section 6.04(h) are hereby deleted in their
                  entirety and the following substituted in their stead:

                  (h) equity investments, loans or advances made by any Loan
                  Party to any Foreign Subsidiary in an aggregate amount not to
                  exceed $10,000,000 outstanding at any time provided that (i)
                  the Borrowers shall be in compliance with the provisions of
                  Section 6.11 hereof, immediately prior to, and immediately
                  after giving effect to, such investment, loan or advance, and
                  on a twelve month pro forma basis thereafter, and (ii) no
                  Default or Event of Default exists immediately prior to, or
                  after giving effect, to any such investment, loan or advance;

         h.       The provisions of Section 6.04(i) are hereby deleted in their
                  entirety and the following substituted in their stead:

                  (i) working capital advances to veterinarians who are tenants
                  of properties owned by or leased by a Loan Party in an
                  aggregate amount not to exceed $15,000,000 outstanding at any
                  time, provided that no Default or Event of Default exists
                  immediately prior to, or after giving effect, to any such
                  advance;

         i.       The provisions of Section 6.04(j) are hereby deleted in their
                  entirety and the following substituted in their stead:

                  (j) loans to, or guarantees of obligations of, officers of any
                  Loan Party to exercise incentive stock options of the Lead
                  Borrower, to purchase capital stock of the Lead Borrower or to
                  pay alternative minimum tax obligations of such officers,
                  provided that no Default or Event of Default exists
                  immediately prior to, or after giving effect, to any such loan
                  or guarantee, and provided further that such loans or
                  guarantees shall not exceed an amount equal to $7,500,000.00
                  in the aggregate at any time outstanding;



                                       5.
<PAGE>
         j.       The provisions of Section 6.05 of the Credit Agreement are
                  hereby amended by deleting the final subparagraph in its
                  entirety and substituting the following in its stead:

                  provided that all sales, transfers, leases and other
                  dispositions permitted hereby (other than sales, transfers and
                  other disposition permitted under clause (b)) shall be made at
                  arm's length and for fair value: and further provided that the
                  authority granted under clauses (b) through (e) hereof may be
                  terminated in whole or in part b, the Agents upon the
                  occurrence and during the continuance of any Event of Default.

         k.       The provisions of Section 6.06(a) are hereby deleted in their
                  entirety and the following substituted in their stead:

                  (a) The Loan Parties will not, and will not permit any
                  Subsidiary to, declare or make, or agree to pay or make,
                  directly or indirectly, any Restricted Payment, except as long
                  as no Default or Event of Default exists or would arise
                  therefrom (i) the Loan Parties may declare and pay dividends
                  with respect to their capital stock payable solely in
                  additional shares of their common stock, (ii) the Subsidiaries
                  of the Lead Borrower may declare and pay dividends ratably
                  with respect to their capital stock, and (iii) the Lead
                  Borrower may repurchase its capital stock or declare and pay
                  cash dividends or other distributions if the Payment
                  Conditions are then satisfied.

         l.       The provisions of Section 6.06(b)(iii) are hereby deleted in
                  their entirety and the following substituted in their stead:

                  (iii) redemptions of the Indebtedness due under the Bonds, if
                  the Payment Conditions are then satisfied.

         m.       The provisions of Section 6.09 are hereby deleted in their
                  entirety and the following substituted in their stead:

                  SECTION 6.09 Amendment of Material Documents. The Loan Parties
                  will not, and will not permit any Subsidiary to, amend, modify
                  or waive any of its rights under (a) any leases or subleases
                  relating to real estate, including, without limitation, the
                  Real Estate, or (b) the Bonds, in each case to the extent that
                  such amendment, modification or waiver would be materially
                  adverse to the interests of the Lenders.

         n.       The provisions of Section 6.11(a) are hereby deleted in their
                  entirety and the following substituted in their stead:

                  (a) The Borrowers shall not permit Excess Availability to be
                  less than $20,000,000.00 at any time.

         o.       The provisions of Section 6.11(b) are hereby deleted in their
                  entirety.


                                       6.
<PAGE>
         6.       Amendments to Article VII of the Credit Agreement. The
provisions of Article VII of the Credit Agreement are hereby amended as follows:

         a.       The provisions of Section 7.01(k) of the Credit Agreement are
                  hereby amended by deleting the number "$5,000,000" appearing
                  therein and substituting the number "$25,000,000" in its
                  stead.

         b.       The provisions of Section 7.01(o) of the Credit Agreement are
                  hereby amended by deleting the number "$5,000,000" appearing
                  therein and substituting the number "$10,000,000" in its
                  stead.

         7.       Amendment to Schedules. Schedule 5.01(1) to the Credit
Agreement is hereby deleted in its entirety and a new Schedule 5.01(1) in the
form annexed hereto substituted in its stead.

         8.       Conditions Precedent to Effectiveness. This Third Amendment
shall not be effective until each of the following conditions precedent have
been fulfilled to the satisfaction of the Administrative Agent:

         a.       This Third Amendment shall have been duly executed and
                  delivered by the Required Lenders and the other parties hereto
                  and, shall be in full force and effect and shall be in form
                  and substance satisfactory to the Administrative Agent and the
                  Required Lenders.

         b.       All action on the part of the Borrowers necessary for the
                  valid execution, delivery and performance by the Borrowers of
                  this Third Amendment shall have been duly and effectively
                  taken and evidence thereof satisfactory to the Administrative
                  Agent shall have been provided to the Administrative Agent.

         c.       The Borrower shall have paid to the Administrative Agent, for
                  the pro rata accounts of the Lenders consenting to and
                  executing this Third Amendment, an amendment fee in an amount
                  equal to 25 basis points of the Commitment of each such
                  Lender. Such amendment fee shall be fully earned upon payment
                  and shall not be subject to refund or rebate under any
                  circumstances.

         d.       The Borrower shall have executed and delivered to each of the
                  Lenders an Amended and Restated Revolving Credit Note to
                  reflect the reduction of the Total Commitment.

         e.       The Borrower and each Facility Guarantor shall have provided
                  such additional instruments and documents to the
                  Administrative Agent as the Administrative Agent and its
                  counsel may have reasonably requested.

         9.       Miscellaneous.

         a.       This Third Amendment may be executed in several counterparts
                  and by each party on a separate counterpart, each of which
                  when so executed and delivered shall be an original, and all
                  of which together shall constitute one instrument.



                                       7.
<PAGE>
         b.       This Third Amendment expresses the entire understanding of the
                  parties with respect to the transactions contemplated hereby.
                  No prior negotiations or discussions shall limit, modify, or
                  otherwise affect the provisions hereof.

         c.       Any determination that any provision of this Third Amendment
                  or any application hereof is invalid, illegal or unenforceable
                  in any respect and in any instance shall not affect the
                  validity, legality, or enforceability of such provision in any
                  other instance, or the validity, legality or enforceability of
                  any other provisions of this Third Amendment.

         d.       The Borrowers shall pay promptly after demand all costs and
                  expenses of the Agents, including, without limitation,
                  reasonable attorneys' fees in connection with the preparation,
                  negotiation, execution and delivery of this Third Amendment.

         e.       The Borrowers warrant and represent that the Borrowers have
                  consulted with independent legal counsel of the Borrowers'
                  selection in connection with this Third Amendment and is not
                  relying on any representations or warranties of the Agents,
                  the Lenders or their counsel in entering into this Third
                  Amendment.

         f.       Except as provided herein, all terms and conditions of the
                  Credit Agreement and the other Loan Documents remain in full
                  force and effect. The Borrower hereby ratifies, confirms, and
                  reaffirms all of the representations, warranties and covenants
                  therein contained and acknowledges that the Obligations, as
                  amended hereby, are and continue to be secured by the
                  Collateral.



                                       8.
<PAGE>
         IN WITNESS WHEREOF, the parties have duly executed this Third Amendment
as of the day and year first above written.

                                      PETSMART, INC.
                                      as Lead Borrower and Borrower

                                      By    /s/   Scott A. Crozier
                                         ---------------------------------------
                                      Name:
                                      Title:

                                      PETSMART DIRECT, INC.


                                      By    /s/   Scott A. Crozier
                                         ---------------------------------------
                                      Name:
                                      Title:

                                      PETSMART STORE SUPPORT GROUP, INC.


                                      By    /s/   Scott A. Crozier
                                         ---------------------------------------
                                      Name:
                                      Title:

                                      PETSMART.COM, INC.


                                      By    /s/   Scott A. Crozier
                                         ---------------------------------------
                                      Name:
                                      Title:

                                      PET CATALOG, LLC


                                      By    /s/   Scott A. Crozier
                                         ---------------------------------------
                                      Name:
                                      Title:

                                      FLEET RETAIL FINANCE INC., as
                                      Administrative Agent, as Collateral Agent,
                                      as Swingline Lender, and as Lender


                                      By    /s/   Keith Vercauteren
                                         ---------------------------------------
                                      Name: Keith Vercauteren
                                      Title: AVP
<PAGE>
                                      FLEET NATIONAL BANK, as Issuing Bank


                                      By    /s/   Keith Vercauteren
                                         ---------------------------------------
                                      Name: Keith Vercauteren
                                      Title: AVP

                                      GMAC BUSINESS CREDIT, LLC, as Lender


                                      By    /s/   George Grieco
                                         ---------------------------------------
                                      Name: George Grieco
                                      Title: Director

                                      CONGRESS FINANCIAL CORPORATION (WESTERN),
                                      as Co-Agent and Lender


                                      By    /s/   Gary Whitaker
                                         ---------------------------------------
                                      Name: Gary Whitaker
                                      Title: VP

                                      FOOTHILL CAPITAL CORPORATION, as Lender


                                      By    /s/   Juan Barrera
                                         ---------------------------------------
                                      Name: Juan Barrera
                                      Title:

                                      LASALLE BUSINESS CREDIT, INC. as Lender


                                      By    /s/   William A. Stapel
                                         ---------------------------------------
                                      Name: William A. Stapel
                                      Title: F.V.P.

<PAGE>
                                      GENERAL ELECTRIC CAPITAL CORPORATION
                                      (successor to Heller Financial, Inc. and
                                      debis Financial Services, Inc.), as Lender


                                      By    /s/   W. Jerome McDermott
                                         ---------------------------------------
                                      Name: W. Jerome McDermott
                                      Title: Duly Authorized Signatory

                                      IBJ WHITEHALL BUSINESS CREDIT CORPORATION,
                                      as Lender


                                      By    /s/   Brian Kennedy
                                         ---------------------------------------
                                      Name: Brian Kennedy
                                      Title: Vice President

                                      SIEMENS FINANCIAL SERVICES, INC., as
                                      Lender


                                      By    /s/   Frank Amodio
                                         ---------------------------------------
                                      Name: Frank Amodio
                                      Title: Vice President-Credit

                                      ORIX FINANCIAL SERVICES, INC., as Lender


                                      By    /s/   J. Paul Hicks
                                         ---------------------------------------
                                      Name: J. Paul Hicks
                                      Title: First Vice President

                                      THE PROVIDENT BANK, as Lender


                                      By    /s/   Cary M. Sierzputowski
                                         ---------------------------------------
                                      Name: Cary M. Sierzputowski
                                      Title: Vice President
<PAGE>
                         CONSENT OF FACILITY GUARANTORS

          The undersigned, Facility Guarantors, each hereby consent to the Third
Amendment to Agreement and each acknowledge that their Guarantee of the
Obligations, the Security Agreement and all other Loan Documents executed by
each of them remains in full force and effect.

          IN WITNESS WHEREOF, the Facility Guarantors have caused this Consent
to Third Amendment to be executed and their seals to be hereto affixed as the
date first above written.

                                            STATE LINE TACK, INC.
                                            PETSMART VETERINARY SERVICES, INC.
                                            AUTHORITY PET FOOD COMPANY
                                            PACIFIC COAST DISTRIBUTING, INC.
                                            PETSTUFF CANADA (USA) HOLDINGS, INC.
                                            PETSTUFF NOVA SCOTIA, INC.
                                            3003300 NOVA SCOTIA COMPANY

                                            By   /s/   Scott A. Crozier
                                               ---------------------------------
                                            Name: Scott A. Crozier

                                            Authorized Signatory