Item 1.01 Entry into a Material Definitive Agreement

MWI Veterinary Supply Co. ("MWI") a wholly-owned subsidiary of MWI Veterinary Supply, Inc., and Pfizer, Inc. ("Pfizer") have entered into a Companion Animal AAHA MarketLink Management Agreement, effective September 1, 2009, which was executed and delivered by Pfizer to MWI on October 31, 2009.

Under the Companion Animal AAHA MarketLink Management Agreement, MWI is entitled to purchase designated companion animal products from Pfizer and resell them to selected veterinary hospitals serviced by MWI who are members of the American Animal Hospital Association. In connection with its resale of the Pfizer companion animal products, MWI will be paid a logistics fee and may receive certain incentive payments from Pfizer.

This agreement expires on December 31, 2009 and may be terminated by either party, with or without cause, upon thirty days written notice to the other party. Pfizer may also terminate the agreement upon fifteen days written notice to MWI in the event it determines that MWI has failed to comply with certain terms and conditions of the agreement. Pfizer may also terminate the agreement upon thirty days written notice to MWI in the event that MWI fails to meet certain sales goals for two consecutive months.

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