Outfoxed / Rita Mae Brown.

Enhanced descriptions from Syndetics:

In the world of Virginia foxhunting, hunters, horses, hounds, and foxes form a lively community of conflicting loyalties. The center of this community is Jane Arnold, Master of the Jefferson Hunt Club. Nearing seventy, Jane must select a joint-master to ensure a smooth transition of leadership. It is an honor of the highest order -- and one that any serious social climber would covet.

Virginian to the bone, with a solid foxhunting background, Fontaine Buruss is an obvious candidate, but his philandering and money squandering has earned him a less than sparkling reputation. Then there is Crawford Howard, a Yankee in a town where Rebel bloodlines are sacred. Still, Crawford has money -- and maintaining a first-class hunt club is far from cheap.

With the competition flaring, Southern gentility files out the window and a small town's secrets are made public. And when opening hunt day ends in murder, Jane realizes a member of her hunt must be responsible. Only she, with the help of a few cleverfoxes and hounds, can lay the trap to catch a killer.

Outfoxed is a must-read for both animal lovers and fans of whodunit mysteries.