The Macabre World of Lavender Williams (2009)

Eight year-old Lavender Williams, who recently lost her mother to cancer, sets off on an epic journey to find her Dad, whom she's never met. Her only companion is Lester, her late pet who's returned from the grave to help her. But the journey won't be easy for the girl and her zombie dog, for the evil presence of Sheriff Murdstone stalks them at every turn.