"Hank the Cowdog: Let Sleeping Dogs Lie" by John Erickson (Book 6)

Guilty until proven innocent? Who - or what - has been killing chickens on the ranch? And what is Hank the Cowdog, Head of Ranch Security, going to do about it?

Using his top-notch law enforcement skills, Hank launches one of the hardest-hitting investigations of his career. No one is to be trusted, and everyone is a suspect - even Hank! With no clues and no evidence, the case seems uncrackable. Can Hank solve the crime - and prove his own innocence - before he's relieved of his command?