Shiroi Kiba White Fang Monogatari

Both movies has a boy and his dog (or in the case of White Fang, a wolf) as main hero and are very similar, except White Fang has no supernatural elements. You will definitely like both of them.  

Both have dogs as protagonist, and they are vey similar. I found that much of the elements used in Ginga Nagareboshi Gin were taken of the novel of Jack London on which Shiroi Kiba is based, so they have much elements in common (like dogs fights, locations, some characters, etc)