Big expectations for the future and a CEO paid big bucks have led Chesterbrook’s AmerisourceBergen pharmaceutical distributor, Chester County’s only Fortune 500 company, to place a big bet on a very different line of pharmaceutical.

This week’s big deal is the $2.5 billion buyout of MWI Veterinary Supply, a move that brings animal health to AmerisourceBergen for the first time.

Chester County’s highest-paid CEO, Steven H. Collis, called the strategy a “logical extension” of the company’s pharmaceutical work into a growing domestic and international market, according to a WTOP report.

Investors drove stock prices for both companies higher in response to the news. The deal is expected to close early this year.

Read more details of the acquisition and background on the Boise-based MWI on WTOP here.