Inside of a Dog: What Dogs See, Smell, and Know

by Alexandra Horowitz

one distinctive thing: a close, even pressing, covering of the back, chest, and sometimes the head. There are occasions when wolves get pressed upon the back or head: it is when they are being dominated by another wolf, or scolded by an older wolf or relative. Dominants often pin subordinates down by the snout. This is called muzzle biting, and accounts, perhaps, for why muzzled dogs sometimes seem preternaturally subdued. And a dog who “stands

begin by considering what he called their umwelt (OOM-velt): their subjective or “self-world.” Umwelt captures what life is like as the animal.

If we want to understand the life of any animal, we need to know what things are meaningful to it.

The first way to discover this is to determine what the animal can perceive: what it can see, hear, smell, or otherwise sense. Only objects that are perceived can have meaning to the animal;

Second, how does the animal act on the world?

these two components—perception and action—largely define and circumscribe the world for every living thing.

As it turns out, to the dog, a rose is neither a thing of beauty nor a world unto itself. A rose is undistinguished from the rest of the plant matter surrounding it—unless it has been urinated upon by another dog, stepped on by another animal, or handled by the dog’s owner. Then it gains vivid interest, and becomes far more significant to the dog than even the well-presented rose is to us.

Even the objects in a room are not, in some sense, the same objects to another animal.

What we think an object is for, or what it makes us think of, may or may not match the dog’s idea of the object’s function or meaning.

Objects are defined by how you can act upon them: what von Uexküll calls their functional tones—as though

But other things that we identify as chairlike are not so seen by dogs: stools, tables, arms of couches. Stools and tables are in some other category of objects: obstacles, perhaps, in their path toward the eating tone of the kitchen.

good many objects in the world have an eating tone to the dog—probably many more than we see as such. Feces

To a dog, a hammer doesn’t exist. A dog doesn’t act with or on a hammer, so it has no significance to a dog. At least, not unless it overlaps with some other, meaningful object: it is wielded by a loved person; it is urinated on by the cute dog down the street; its dense wooden handle can be chewed like a stick.

They aren’t seeing the world from the dog’s perspective: the way he sees it.

Initially, there’s not much difference between the beds—except, perhaps, that our bed is infinitely more desirable. Our beds smell like us, while

Even then, what the dog knows is less “human bed” versus “dog bed” but “thing one gets yelled at for being on” versus “thing one does not get yelled at for being

In the dog umwelt beds have no special functional tone. Dogs sleep and rest where they can, not on objects designated by people for those purposes. There may be a functional tone for places to sleep: dogs prefer places that allow them to lie down fully, where the temperature is desirable, where there are other members of their troop or family around, and where they are safe. Any flattish surface in your home satisfies these conditions.

Make one fit these criteria, and your dog will probably find it just as desirable as ...

To watch the rats in the predictable environments jump with alacrity at every new sound is to see optimism in action. Small changes in the environment were enough to prompt a large change in outlook. Rat lab workers’ intuitions about the mood of their charges may be spot-on.

lick the face and muzzle of their mother

when she returns from a hunt to her den—in order to get her to regurgitate for them.

our mouths taste great to dogs. Like wolves and humans, dogs have taste receptors for salty, sweet, bitter, sour, and even umami,

licks to my face often correlated with my face having just overseen the ingestion of a good amount of food.

no longer serves only the function of asking for food; now it is used to say hello. Dogs and wolves muzzle-lick simply to welcome another dog back home, and to get an olfactory report of where the homecomer has been or what he has done.

licks are a way to express happiness that you have returned.

we’ve made in breeding dogs led to some intentional designs

We need to appreciate what the dog smells, sees, and hears . .

body of the dog leads us to the brain of the dog.

arose from just one ancient Canidae line, animals most likely resembling the contemporary gray wolf. When

Carrot-considerers arose out of moose killers through the second source: us.

humans have also selected traits—physical features and behaviors—

design was utterly unintentional.

Kept in pens, bred for their choice fur coats, particularly long and soft, the fox was not tamed but was captive.

no canids are fully domesticated other than the dog:

domestication doesn’t happen spontaneously.

he selectively chose and ...

chose were those foxes that were the least fearful of or aggressi...

others accepted the food and even wagged and whimpered at the experimenter, inviting rather than discouraging interaction. These were the foxes Belyaev selected. By some normal variation in their genetic code, these animals were naturally calmer around people, even interested in people.

“tame” foxes were allowed to mate, and their young were tested the same way. The tamest of those were mated, when they were old enough; and their young; and their young.

“domesticated elite”: not just accepting contact with people, but drawn to it, “whimpering to attract attention and sniffing and licking” . . . as dogs do. He had created a domesticated fox.

that forty genes now differ between Belyaev’s tame foxes and the wild silver fox. Incredibly,

with that genetic change came a number of surprisingly familiar physical changes: some of the later-generation foxes have multicolored, piebald coats, recognizable in dog mutts everywhere. They have floppy ears and tails that curl up and over their backs. Their heads are wider and their snouts

physical characteristics came along for the ride, once

both are the common result of a gene or set of genes.

One idea is that the humans’ relatively fixed communities produced a large amount of waste, including food waste. Wolves, who will scavenge as well as hunt, would have quickly discovered this food source.

accidental natural selection of wolves who are less fearful of humans would have begun.

the calmer wolves would have more success living on the edge of human society.

inadvertent selection of animals who are nearby, useful, or pleasing, allowing them to loiter on the edges of human society.

Finally, and most familiar, domestication involves breeding animals for specific characteristics.

of a subtle split as long as 145,000 years ago between pure wolves and those that were to become dogs.