TBH I can't really understand the point of encouraging a dog to scavenge for it's food (in reference to hiding Barf around the garden) when you would never want them to do that with game when you're working the dog.
For working dogs, I entirely agree - but dogs that are trained to work are mentally stimulated in other ways; unlike the thousands of pets that are offered little in the way of mental challenge on a daily basis
Hiding/scattering meals is a relatively simple way for even the busiest, and least-committed of dog owners to stimulate their dog, so I do understand why Dunbar has recommended this approach....even if all dogs don't *need* it, it doesn't do any harm and may well reduce the chance some dogs becoming destructive
It also offers calorie-burning exercise that some dogs desperately need
