Walking Dogs?!

A group of white dogs with red, bloody markings on their faces and chests run down a small-town street, pursued by a larger dog wearing a sheriff's hat and holding a gun; the scene shifts to a desolate, debris-strewn alley where the dogs continue running, now joined by a dog in a bandana holding a sword, before the setting changes to the interior of a dilapidated building where the sheriff dog runs through a doorway.