A much better take on the Western zombie concept is Andre Albrecht's 2006 short film WASTED WEST. A tribute to George Romero and Sergios Leone and Corbucci, this should appeal to both fans of the living dead and spaghetti westerns.
While it's a little on the slow side, without a solid narrative, Albrecht still delivers a fun ride thanks to his strong filmmaking chops. With a more developed screenplay, I'd really like to see this as a feature; hopefully Albrecht can use this to drum up enough capital to make that a reality.
Though hopefully he leaves out the cheesy CGI dog.