FIRST AMENDMENT TO SECOND AMENDED AND RESTATED CREDIT AGREEMENT

THIS FIRST AMENDMENT TO SECOND AMENDED AND RESTATED CREDIT AGREEMENT (" Amendment "), dated effective as of May 5, 2009, is made and entered into by and among WALCO INTERNATIONAL, INC., a Delaware corporation (the " US Borrower "), KANE VETERINARY SUPPLIES LTD. (the " Canadian Borrower "), an Alberta corporation, THE UNDERSIGNED GUARANTORS WHICH ARE PARTIES TO THE CREDIT AGREEMENT (as hereinafter defined), as amended by this Amendment (each a " Guarantor " and collectively, the " Guarantors "), THE UNDERSIGNED GRANTOR WHICH IS A PARTY TO THE CREDIT AGREEMENT (the " Grantor "), THE UNDERSIGNED FINANCIAL INSTITUTIONS WHICH ARE PARTIES TO THE CREDIT AGREEMENT (each, together with its successors and assigns, a " Lender " and collectively, the " Lenders "), JPMORGAN CHASE BANK, N.A., a national banking association, as the administrative agent for the US Lenders (in such capacity, the " US Administrative Agent "), JPMORGAN CHASE BANK, N.A., TORONTO BRANCH, as the administrative agent for the Canadian Lenders (in such capacity, the " Canadian Administrative Agent "), and U.S. BANK NATIONAL ASSOCIATION, as Documentation Agent for the Lenders.  The US Borrower and the Canadian Borrower shall sometimes hereinafter be collectively referred to as the " Borrowers "), and the US Administrative Agent and the Canadian Administrative Agent shall sometimes hereinafter be collectively referred to as the " Administrative Agents ".

RECITALS :

WHEREAS, the US Borrower, KVSL Acquisition, Ltd. (predecessor in interest to the Canadian Borrower), the Guarantors, the Grantor, the Administrative Agents and the Lenders are parties to a Second Amended and Restated Credit Agreement dated as of October 15, 2007 (the " Credit Agreement "); and

WHEREAS, the Borrowers, the Guarantors, the Grantor, the Administrative Agents and the Lenders have agreed, on the terms and conditions herein set forth, that the Credit Agreement be amended in certain respects.

AGREEMENTS :

NOW, THEREFORE, in consideration of the premises and the mutual agreements, representations and warranties herein set forth, and for other good and valuable consideration, the receipt and sufficiency which are hereby acknowledged and confessed, the Borrowers, the Guarantors, the Grantor, the Administrative Agents and the Lenders do hereby agree as follows:

Section 1.                              General Definitions .  Capitalized terms used herein which are defined in the Credit Agreement shall have the same meanings when used herein.

Section 2.                              Modification of Interest Rate Provisions .

(a)            Modification of Applicable Rate Definition .  The term “Applicable Margin” contained in Section 1.1 of the Credit Agreement is hereby amended and restated in its entirety to hereafter be and read as follows:

Applicable Margin shall mean, a rate per annum of 3.50% for LIBOR Borrowings and CDOR Rate Borrowings and a rate per annum of 1.00% for CB Floating Rate Borrowings, Canadian Prime Rate Borrowings and US Base Rate (Canada) Borrowings; provided, however, that as of the end of each fiscal quarter of the US Borrower (commencing with the period ending June 30, 2009), the Applicable Margin shall be adjusted upward or downward, as applicable, to the respective amounts shown in the schedule below based on the Leverage Ratio for the Credit Parties and their Subsidiaries, on a Consolidated basis, tested as of the end of the applicable fiscal quarter of the Credit Parties.  For purposes hereof, any such adjustment in the respective amounts of the Applicable Margin, whether upward or downward, shall be effective ten (10) Business Days after the applicable Annual Audited Financial Statements of the Credit Parties or the Monthly Unaudited Financial Statements of the Credit Parties for the applicable fiscal quarter, as the case may be, have been delivered to and received by the Administrative Agent in accordance with the terms of Sections 6.3(a) and 6.3(b) hereof; provided, however, if any such financial statements are not delivered in a timely manner as required under the terms of Sections 6.3(a) and 6.3(b) hereof, the Applicable Margin from the date such financial statements were due until ten (10) Business Days after the Administrative Agent and Lenders receive the same will be the highest level set forth below for the Applicable Margin.

Notwithstanding the foregoing or any other provision to the contrary contained in this Agreement or in any other Loan Document, the Applicable Margin for that portion of the US Revolving Loans deemed funded on a “first drawn” basis under the Additional US Availability Credit (i.e., the amount of US Revolving Loans then outstanding up to the then applicable amount of the Additional US Availability Credit) will be equal to the sum of (i) the amount of the Applicable Margin as determined above plus (ii) an additional 0.75%.

(b)            Addition of New Interest Rate Related Definitions .  New definitions for “Adjusted CB Floating Rate,” “Adjusted One Month LIBOR Rate” and “CB Floating Rate” are  hereby added to Section 1.01 of the Credit Agreement to hereafter read as follows:

Adjusted CB Floating Rate shall mean, for any day, a rate per annum equal to the sum of (a) the CB Floating Rate for such day and (b) the Applicable Margin.

Adjusted One Month LIBOR Rate means, for any day, an interest rate per annum equal to the sum of (a) 2.50% per annum plus (b) (i) the interest rate per annum determined by Lender by reference to the Reuters Screen LIBOR01 Page (or on any successor or substitute page) to the rate at approximately 11:00 a.m. London time on such day (or if such day is not a Business Day, on the immediately preceding Business Day), for US Dollar deposits with a maturity equal to one (1) month, multiplied by (ii) Statutory Reserves.

CB Floating Rate means the Prime Rate; provided that the CB Floating Rate shall, on any day, never be less than the Adjusted One Month LIBOR Rate on such day (or if such day is not a Business Day, on the immediately preceding Business Day).   Any change in the CB Floating Rate due to a change in the Prime Rate or the Adjusted One Month LIBOR Rate shall be effective from and including the effective date of such change in the Prime Rate or the Adjusted One Month LIBOR Rate, respectively.

(c)            Deletion of “Alternate Base Rate” Definition in Credit Agreement and Replacement of “Alternate Base Rate” and “Alternate Base Rate Borrowing” Definition Usage in Credit Agreement with “Adjusted CB Floating Rate” and “CB Floating Rate Borrowing” Definitions .   The definition for “Alternate Base Rate” in Section 1.01 of the Credit Agreement is hereby deleted from the Credit Agreement in its entirety.   Each and every reference to the term “Alternate Base Rate” in any other provision of the Credit Agreement is hereby deemed replaced by a reference to the “Adjusted CB Floating Rate,” and each and every reference to the term “Alternate Base Rate Borrowing” in any provision of the Credit Agreement is hereby deemed replaced by a reference to the “CB Floating Rate Borrowing.”

Section 3.                              Modification of US Borrowing Base Definition .  The “US Borrowing Base” definition contained in Section 1.1 of the Credit Agreement is hereby amended and restated in its entirety to hereafter be and read as follows:

US Borrowing Base shall mean, as of any date, the amount of the then most recent computation of the US Borrowing Base, determined by calculating the amount equal to the following:

Notwithstanding anything to the contrary set forth in the immediately preceding sentence, the Administrative Agent reserves the right to adjust downward, to a level acceptable to the Administrative Agent in its Permitted Discretion, the advance rates set forth above for Eligible Accounts of the US Borrower and the Domestic Subsidiaries if the average dilution percentage for all Accounts of the US Borrower and the Domestic Subsidiaries ever exceeds five percent (5%).  For purposes hereof, “average dilution percentage” shall mean for each dollar of gross sales by the US Borrower and the Domestic Subsidiaries, the average percentage of such dollar of gross sales that is not collected by the US Borrower and the Domestic Subsidiaries for any reason, including without limitation, any credits, rebates, refunds, returns, discounts or any other reason.  The US Borrowing Base may be computed by the Administrative Agent on as frequent as a daily basis (based on all information reasonably available to the Administrative Agent, including without limitation, the periodic reports and listings delivered to the Administrative Agent in accordance with Sections 6.3(e) , (f) and (g) hereof).

Section 4.                              Modification of Change of Control Definition .  Subparagraph (a) of the “Change of Control” definition contained in Section 1.1 of the Credit Agreement is hereby amended and restated in its entirety to hereafter be and read as follows:

(a)           at any time any Person and/or its respective Affiliates (other than Charlesbank and its Affiliates) shall either (i) beneficially own in the aggregate, directly or indirectly, 35% or more of the aggregate voting power of all issued and outstanding classes of Equity Interests in the Parent having the right to elect Board of Directors of the Parent, or (ii) have the right to cause enough of their nominees in the aggregate to be elected or appointed, and remain serving at all times as, Board of Directors of the Parent so as to constitute a majority of such Board of Directors.

         (b)       the Account has payment terms of 30 days or less, or if the Account has payment terms of 31 to 120 days, such Accounts having payment terms of 31 to 120 days shall not constitute more than fifteen percent (15%) of the total Eligible Accounts or $12,000,000 in the aggregate, whichever is less.

Section 6.                              Modification of Issuing Bank Definition .  The term “Issuing Bank” contained in Section 1.1 of the Credit Agreement is hereby amended and restated in its entirety to hereafter be and read as follows:

Issuing Bank shall mean (a) with respect to Letters of Credit issued for the account of the US Borrower, either JPMorgan or U.S. Bank National Association, in its respective capacity as an issuer of US Letters of Credit hereunder, (b) with