Mr. Malo was recruited to race by his friend, Kathy Watson, from Sale Creek, Tenn. To prepare, Ms. Watson and her border collies, Rolex and Jack, spent three weeks dock-diving, a sport where dogs launch off a platform to chase toys in the water.
But when her husband declined to run with her — “because he’s sane,” she said — she asked Mr. Malo to team up with Jack.


