Most dog breeds have a genetic predisposition to follow the calling of what they were bred to do:
Shepherds were bred to shepherd and protect.
Small terriers were bred to dig out and rid areas of vermin.
Poodles and Retrievers were bred to retrieve- especially in water.
Pitties were bred for their muscular strength.
Heelers and Collies were bred to herd livestock
How does one help to "scratch" their dog's natural itch?
You get them involved in events that are built specifically for the need that matches their genetic disposition. Find local clubs and groups that offer activities such as barn hunts, flirt poles, lure courses, dock diving, sniffaris, protection work, livestock guarding, tug-o-war, and puzzles.
*Please note that not every breed pulls from its genetic makeup.*
There isn't much Labs love more than working in the water!