Sorry, I don’t have a picture for this but….use a piece of PVC pipe and drill holes in it throughout the pipe (diff. size holes, same size holes, 4 holes, 24 holes…whatever you want). You can make it a 6″ piece of pipe or vary it depending on the size of the dog. I have very high drive German Shepherds that need a job, so this works great at keeping them occupied on my long days at work.
I have caps on both end of the pipe. You can fill it with treats or regular dog food. As they push it with their nose, or whack it with their paws, it will dispense whatever is inside. Larger holes make it easier for the dogs who aren’t interested in working so hard for their food.