X0303 4 2011-05-02 0 0001323974 MWI Veterinary Supply, Inc. MWIV 0001334075 Ryan John R 3041 W. PASADENA DR. BOISE ID 83705 0 1 0 0 Vice President of Marketing Common Stock, par value $0.01 per share 2011-05-02 4 M 0 1000 .1818 A 11055 D Common Stock, par value $0.01 per share 2011-05-02 4 S 0 1000 82.6710 D 10055 D Employee Stock Option (right to buy) .1818 2011-05-02 4 M 0 1000 0 D 2009-09-30 2012-06-18 Common Stock, par value $0.01 per share 1000 0 D The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on November 18, 2010. The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $82.3350 to $83.17, inclusive. Mr. Ryan has provided to MWI Veterinary Supply, Inc. (the "Company") and undertakes to provide to any security holder of the Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote. Ryan Cleverley as attorney-in-fact for John R Ryan 2011-05-03