X0306 4 2013-03-18 0 0001323974 MWI Veterinary Supply, Inc. MWIV 0001333286 Thompson Mary Patricia B 3041 W. PASADENA DR. BOISE ID 83705 0 1 0 0 Senior VP, Secretary and CFO Common Stock, par value $0.01 per share 2013-03-18 4 S 0 873 132.9053 D 40166 D Common Stock, par value $0.01 per share 2013-03-18 4 S 0 3801 131.6804 D 36365 D Common Stock, par value $0.01 per share 2013-03-18 4 S 0 2826 131.0507 D 33539 D Common Stock, par value $0.01 per share 2300 I By Spouse Common Stock, par value $0.01 per share 333 I By Son Common Stock, par value $0.01 per share 333 I By Daughter The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $132.84 to $133.41, inclusive. Ms. Thompson 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. The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $131.26 to $132.25, inclusive. Ms. Thompson has provided to 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. The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $130.89 to $131.21, inclusive. Ms. Thompson has provided to 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 Mary Patricia B. Thompson 2013-03-19