UNITED STATES


SECURITIES AND EXCHANGE COMMISSION


Washington, D.C.  20549





FORM 10-Q/A


(Amendment No. 1)





x
QUARTERLY REPORT PURSUANT TO SECTION 13 or 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934





For the quarterly period ended March 31, 2011




OR





o
TRANSITION REPORT PURSUANT TO SECTION 13 or 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934





For the transition period from                      to





Commission File Number:  000-51468


MWI VETERINARY SUPPLY, INC.


(Exact name of registrant as specified in its Charter)





Delaware

02-0620757(State of Incorporation)

(I.R.S. Employer Identification Number)3041 W. Pasadena Dr.Boise, ID

83705(Address of principal executive offices)

(Zip Code)(208) 955-8930(Registrant’s telephone number, including area code)


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





Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).   Yes o  No  o





Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act.





Large accelerated filer
o

Accelerated filer
xNon-accelerated filer
o  (Do not check if a smaller reporting company)
Smaller reporting company
o








Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes o No x





The number of shares of the registrant’s common stock, $0.01 par value, outstanding as of April 29, 2011 was 12,551,647.













EXPLANATORY NOTE




MWI Veterinary Supply, Inc. (the “Company”) filed its Quarterly Report on Form 10-Q for the quarter ended March 31, 2011 with the Securities and Exchange Commission on May 5, 2011 (the “Form 10-Q”). The Company is filing this Amendment No. 1 to the Form 10-Q (the “Amendment”) solely for the purpose of re-filing Exhibit 10.1 in response to comments from the Securities and Exchange Commission provided in connection with a request for confidential treatment.  This Amendment amends and restates the exhibit index included in Part II, Item 6 of the Form 10-Q.




The Form 10-Q has not been updated other than for the change to Part II, Item 6 indicated above. No other items included in the Form 10-Q have been amended, and such items remain in effect as of the filing date of the Form 10-Q. This Amendment does not purport to provide an update or a discussion of any developments at the Company subsequent to the original filing date of the Form 10-Q.




In addition, this Amendment includes, as Exhibits 31.1, 31.2 and 32, new certifications by our principal executive officer and principal financial officer pursuant to Sections 302 and 906 of the Sarbanes-Oxley Act of 2002.








PART II.  OTHER INFORMATION





ITEM 6.
EXHIBITS10.1

2011 Livestock Products Distribution Agreement between MWI Veterinary Supply, Inc. and Pfizer, Inc. effective as of January 1, 2011 †10.2

2011 Strategic Brands Distribution Agreement between MWI Veterinary Supply, Inc. and Pfizer, Inc. effective as of January 1, 2011 *†15

Letter re: Unaudited Interim Financial Information *31.1

Certification of CEO Pursuant to Section 302 of the Sarbanes-Oxley Act of 200231.2

Certification of CFO Pursuant to Section 302 of the Sarbanes-Oxley Act of 200232

Certification Pursuant to 18 U.S.C. Section 1350, as Adopted Pursuant to Section 906 of the

Sarbanes-Oxley Act of 2002


* Previously filed.


† Certain portions of the exhibit have been omitted pursuant to a confidential treatment request submitted to and approved by the SEC.








SIGNATURE




Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.


Date: July 20, 2011



MWI VETERINARY SUPPLY, INC.By:

/s/ Mary Patricia B. ThompsonMary Patricia B. ThompsonSenior Vice President of Finance and Administration, Chief Financial Officer