Every Dog Has His Day (Hank the Cowdog #10) by John R. Erickson

Hank the Cowdog: Head of Ranch Security. This canine is a cross between Maxwell Smart and John Wayne. 

Hank is literally at the end of his rope in his tenth adventure. It's roundup time at the ranch and Hank is left behind, tied to a post, while a high-bred border collie named Bennie takes his place. How can Hank restore himself as Head of Ranch Security and reclaim his fame and fortune?