User blog comment:Hackandslash1994/Fanboys of Wolverine and Deadpool !/@comment-5116372-20131002220300

They are only brothers in the movies.

It was originally believed they were brother because Dog Logan as an adult looks like Sabretooth but Dog is in the present and has interacted with Sabretooth so they aren't the same character. They have different last names as well because James Howlett thought he was the son of John Howlett (I think it was) but his mother had an affair with the grounds keeper Thomas Logan (I think it is) who is the real father of Wolverine.