Dogs smell things in vibrant detail compared with humans. Humans can smell dinner cooking but dogs can tell exactly what all the ingredients are. What about other dog senses? How do dogs compare with humans?
Dog Senses: Auditory and More
Let’s start with hearing, and another way animals detect sounds.
Dogs hear high-frequency sounds very well: whistles, squeaks, squeals, the high voices of children, high tones of vacuum cleaners. They can hear sounds that are 13 – 19 decibels quieter than humans can hear. This means that a human may consider a room to be completely silent, while a dog knows better!
Humans hear low-frequency sounds well: human speech, bass drums, thunder, deep voices. Humans can determine the location of a sound more closely than dogs can.
For comparison, cats hear all the things dogs hear, but cats hear even higher tones.
There’s another type of sense that allows sound detection. Dogs, cats, and humans feel sounds of lower frequency, like the rumble of an earthquake or a deep musical bass beat.
What do Dogs See?
Dogs’ visual acuity is about 20/75, compared to humans’ 20/20. This indicates they are not great at seeing static detail. Dogs see moving things better; they can see a moving object at a distance of almost twice as far as they can see a static object. Dogs can see well in dim light and detect subtle motion more quickly than humans. Dogs see color, but some colors are clearer than others. Their distance vision is generally poor, but some dog breeds are more visual than others and see better at distances. Dogs’ depth perception varies with the shapes of their faces. Though their depth perception is sufficient for their lifestyle, it is best when they’re looking straight ahead and it’s probably blocked by their noses when they’re looking at something below eye level, depending on nose length. Humans (and cats) don’t tend to have this problem!
Humans have the edge in distance vision. A broad range of colors, really wavelengths of light, are visible to humans. Fine details are also clear to humans, where dogs and cats see more general forms. Humans are pretty immune to subtle movement; motion has to be more dramatic to be visible. And humans don’t see well in the dark, compared to dogs and cats.
Cats have great peripheral vision and they see quite well in the dark. Scientists aren’t sure what color looks like to cats. Cats don’t see well over about 20 feet away, so things can startle them when they suddenly cross the threshold into the visual range of cats.
What do Dogs Feel?
Dogs and cats feel touch through their skin in a similar way to humans. The big difference is their “Tactile Vibrissae” – Whiskers. Whiskers are located on the muzzle and eyebrows, cheeks and throat, and cats have them on the backs of their wrists, or the lowest bend on their forelegs. Each whisker has nerve endings at the base, deep in the follicle they emerge from. These amazing organs transmit sensory information when they are touched or even moved by airflow. They collect information from the environment according to how much they are moved and in which direction. This information is carried by neural impulses to the brain for processing. Dogs, cats, and other animals may be able to use this information to detect prey or to determine whether what is approaching is a predator or a friend. They can avoid crashing into things they’re running past, either when their whiskers touch something or as the air rushes past their whiskers. In effect, whiskers expand the boundaries of a dog’s head! They help dogs detect things that could bruise or scratch them before they get close enough for that to happen.
Dogs’ Olfactory Senses: That Amazing Sense of Smell
It’s well-known that dogs can detect tiny amounts of odor. A human might feel proud to be able to smell that a cup of coffee has sugar added; dogs can smell a teaspoon of sugar in a million gallons of water.
Some studies suggest that humans may be able to smell more than we realize but humans don’t tend to focus on the sense of smell as much as the senses of vision and hearing, so it doesn’t get developed.
Cats may be able to distinguish even more detailed scents that dogs can. Cats’ sense of smell drives their appetites; their sense of taste is minimal.
Dog Senses: Everyone is an Individual
As with any quality, there is variability among individuals as to the workings of the senses. This is one way humans have used selective breeding to develop the many types of dogs in the world. Think about the types of dogs who use vision or hearing more, and those who have senses of smell even more highly developed than dogs in general. The world truly looks, sounds, and smells differently to dogs and cats than to humans, and their whiskers help them stay safe. Our Dog Reading Course may help you discover ways to tell what your dog is focusing on and how he feels about it!