How about trying a frisbee - it definitly is different then throwing a bumper or paint roller. Just thought of this this morning because with the rain the past couple days the snow is gone and I found the Frisbee again which my pup goes crazy for. He does pretty good with the paint rollers and other things, but that Frisbee drives him crazy - not sure why other then the flying motion. We had some fun with it this morning. Good luck.