H. Beam Piper 
Lone Star Planet [EPUB ebook] 

The story originated in a suggestion by H. L. Mencken and presents a world on which the assassination of politicians is accepted practice. It eventually won a Prometheus Hall of Fame Award in 1999. New Texas, the Lone Star Planet: its citizens figure that name about says it all. The Solar League ambassador to the Lone Star Planet has the unenviable task of convincing New Texans that a s’Srauff attack is imminent, and dangerous. Unfortunately it’s common knowledge that the s’Srauff are evolved from canine ancestors — and not a Texan alive is about to be scared of a talking dog! But unless he can get them to act, and fast, there won’t be a Texan alive, scared or otherwise!