The other night when my family and I pondered this question I had a "Eureka." I realized only one guy (and a few elves) would be able to sort this one out. Our family dog, who goes by the name Boondock, is not brilliant but he's incredibly thoughtful and perceptive. Most of all, he is the most photogenic dog in the history of all our family pets. When we show him all his great photos, he gets a funny gleam in his eyes. He puts his ears back and licks his lips bashfully. Is he recognizing himself? Can his vision process what is on a photo? And then can he realize how silly he looks in a hat or begging to be photographed? Or are we over-anthropomorphizing?
-- Karen in Carlsbad
After your scientific report on Project Mickey Schmidt it occurred to me, is there such a thing as dognip?
-- I Prefer Dogs, San Diego
As expected, it was only a matter of time before the doggyphiles checked in. Put down their pooper scoopers and took up pencil and paper. Luckily, dogs' brains are a little more transparent than cats'. And since dogs consider us to be dogs, they talk to us a lot, though sometimes we only hear what we want to. Boondock, f'rinstance. He's saying, "Huh? What? Whazzat? CanIeatit, canIeat it? Pet me! Pet me!" Thoughtful, perceptive Boondock doesn't have a clue, Karen. He knows he's the center of attention, which is good; and you're sticking your hand out like you're giving him a treat, which is good, but this treat doesn't smell, which is not good. Not only can he not recognize himself, he can't even see the photograph very well. He can't begin to appreciate how cute he looks wearing goofy hats. All he knows is that when you pull out the funny box and put it in front of your face, he gets all kinds of attention. Then you get excited and say things like "Good boy, Boondock!" Then he gets excited like it's playtime, and the more he keeps it up, the more attention he gets. All the manipulation is exhausting.
Now go find Boondock and look right into his friendly old doggie face. Note where Boondock's dopey old doggie eyes are. Kinda pointing off to each side, yes? That gives dogs good wide-angle vision but poor ability to focus straight ahead at close range. This makes sense when you consider that dogs are designed to hunt and chase down prey, not to be art critics. And dogs are stimulated by things that move. Waving the picture at him might catch his attention, but a plain old Polaroid held in front of his nose simply has no meaning, assuming he can see it at all. That's especially true since most animals don't see things in detail the way we do. They react to larger forms and big movements, not minutiae like the cute expression you've captured when you took the snapshot.
Putting a flashy multicolored hat on Boondock won't help either. Dogs are capable of distinguishing shades of blue and yellow (everything else looks gray), but color vision isn't very useful to an animal designed to hunt in twilight, so colors aren't natural attractants. In short, there's not a thing about your adorable portraits that Boondock finds interesting. All he knows is, you seem to be having fun, and he wants to join in. You're top dogs in his pack, after all.
Of course, another reason the picture is boring is because it doesn't smell like anything worth eating. So is there something we can dip the photo in that will turn Boondock into a snuffling, mooing, drooling ball of wriggling ecstasy? Is there such a thing as dognip? Well, yes and no. The closest you'll come to getting a dog to approximate a cat's catnip behavior is to present him with some fresh dog poop or horse manure or maybe the guts of some long-dead possum. There's every likelihood he'll want to roll around in it eagerly. Just as we're not too sure about the cat-catnip link, we only have guesses about the dog-smelly stuff connection. One guess is that acquiring the smell and taking it back to the pack is a form of communication with the larger group about what's out there; maybe covering a wild dog's own smell made it easier to sneak up on prey. Who knows. In test situations, dogs will react similarly to sharp scents not historically available in the wild: perfume, tobacco, lemon rind. An interesting observation, but useless in explaining the broader behavior. And no, no, no, we will not launch Project Boondock looking for answers.