Shocking pet toy

Ok, so it sounds bad, but... When I was a kid I dropped a 9volt battery on the floor. My black lab went over to investigate and emitted a curious noise after a test lick discovered the principles of electricity. The dog then proceeded to play with this new toy for quite some time. The game being how to pick up and carry the toy without getting shocked. Pup was quite proud when she succeeded. The toy would of course have to be in a tough plastic housing (for a sellable item) with electrical contact spots. Marketing this product could be a challenge. Not for dogs with pacemakers.