Rowdy loves to fly. Paws out, ears akimbo, six-year-old Rowdy has jumped his way to the top of the dogpile in the Dock Dogs “Big Air” world rankings for Golden Retrievers.

At the 2014 GoPro Mountain Games, however, Rowdy lost by a nose in a heartbreaking final round. The (somewhat) rare second-place didn’t phase Willis, however,...