How Dogs Sense the World Around Them

    Have you ever looked at your dog and wondered what it’s like to be them? Imagine hearing, seeing, smelling, tasting and feeling that they do. As good as dogs and humans are at living together- we are so different, and the way our dogs sense the world around them is both mysterious and intriguing.

    How Dogs Hear

    Dogs’ hearing differs from humans’ in two distinct ways- distance and accuracy

    Dogs can hear 4 times the distance that we can and are able to distinguish between similar sounds.

    This is how they recognise your specific car or footfalls. They can also distinguish a sound’s precise origin, rather than a vague direction. This makes them excellent at following sounds right to their source.

    Their ears can operate independently of each other

    They can capture and focus in on a different sound with each ear. You can see this technique in action when your dog’s ears twitch independently towards a certain direction. It’s even possible to determine the direction of a sound that may be inaudible to humans, by the direction your dog’s ears are twitching.

    They can hear higher frequencies

    There are some sounds dogs can hear and we can’t- not due to volume, but due to pitch. Humans can hear sounds that vibrate at a pitch of 20 000 vibrations per second or less, depending on age.  Dogs, however, can hear sounds that vibrate up to 50 000 vibrations per second.

    They have long ear canals with 18 muscles in each

    They can maneuver these muscles to magnify sound through to their inner ear like a megaphone. This is also how they are able to pinpoint sounds, even from far away.  Humans only have 6 muscles in each ear, and can barely maneuver them at all. A human may have to turn their head or walk towards a sound to establish its source. However, dogs can hone in using only their ear muscles.

    How Dogs See

    Dogs see colour similarly to people with red/green colourblindness, or the colours we see at dusk.

    It is difficult for scientists to determine exactly how dogs see, but they have now determined that they do see colour, contrary to what was once believed.

    Evolutionary preference has affected their vision

    Their limited colour vision is due to an evolutionary preference to seeing in low light.

    So, while we can see better in the light than they can, they have us at seeing in the dark.

    They also have an evolutionary preference for perceiving moving objects more easily

    In fact, they can see an object twice as far away if it’s moving, than if it’s not.

    Have you ever thrown a ball a long distance, and your dog has chased it until it landed, then completely lost it?

    The shape of a dog’s skull affects their vision

    Due to the way their vision receptors align in their skulls, dogs with long skulls, like wolf hounds, poodles and Scottish terriers have better long distance vision. Whereas, dogs with short skulls, like French bulldogs, pugs and Yorkshire terriers, have better close-up vision.

    How Dogs Taste

    You may know that a dog’s sense of smell makes up for their relatively poor vision, but did you know that it also makes up for a relatively poor sense of taste?

    Compared to humans, who have around 9000 taste buds, dogs have far fewer with around 1700.

    This means while they’re better at distinguishing similar sounds and smells than we are, they aren’t so good at distinguishing between similar tastes. They rely heavily on their nose to let them know what’s OK to eat.

    Like humans, dogs have receptors for bitter, sweet, salty and sour flavours

    They do, however, have a partiality towards sweet over salty. This can be explained by their sodium-rich ancestral diet, which hasn’t left them with a craving for salt, since they’ve always had a sufficient amount.

    Their sweet tooth stems from their ancestors’ tendency to eat fallen fruits at times when meat was scarce. Humans, on the other hand, have a distinct preference for salty foods.

    Dogs have additional taste receptors to humans

    Dogs have an extremely high taste preference for meat and in fact, have additional taste receptors specifically for meat flavours.

    Even more foreign, are their taste receptors for water. These are located on the tips of their tongues- the area they use to lap up water. They give them a craving when additional water is needed for digestion. They’re particularly active after eating and more so after eating something salty.

    How Dogs Touch

    Without hands, whiskers play an important role in dogs’ ability to feel out in from of themselves

    Their whiskers warn them of things that they can’t necessarily smell or hear, such as air flow. Whiskers are incredibly sensitive and stem from cells deep beneath the skin. They allow dogs to feel the airflow around an object, hence warning them if something is coming towards their face. This is potentially the reason for dogs’ common hyper reaction to having air blow in their faces.

    Other than their whiskers, their sense of touch is more similar to humans’ than any of their other senses

    They feel pain, pressure, body movement and position, temperature and chemical stimulations from their skin, just as we do.

    Dogs have particularly sensitive areas to be mindful of

    They are sensitive to touch at the base of their spine (near the tail), as well as their paw pads and the skin in between. This can cause some dogs to have an aversion to having their paws touched- similar to humans with ticklish feet. It’s important to avoid matted paw hair, which can be painful. Also, be mindful of your dog walking on hot or cold surfaces.

    Human touch, unless painful, has been proven to lower the heart rate, ease anxiety and stimulate relaxation for both dogs and humans.

    How Dogs Smell

    We have truly saved their superpower for last.

    There are still many unknowns about a dog’s sense of smell, but what is known is that it is beyond what is imaginable for a human to experience.

    Imagine the ability to smell a cancer that even a cancer scan failed to find, or trace a single smell to a lost child via the skin cells, while navigating a plethora of smell distractions.

    Estimates as to how much stronger a dog’s sense of smell is than ours range from 10 – 100 000 times

    In her book, Inside of a Dog, Alexandra Horowitz compared their sense of smell to ours by saying,

    “We might notice if our coffee’s been sweetened with a teaspoon of sugar; a dog can detect a teaspoon of sugar diluted in a million gallons of water: two Olympic-sized pools full.” (Horowitz 2009)

    So, how are dogs physically capable of such a remarkable sense of smell?

    Dogs’ nasal cavities are made up of over 300 million olfactory receptors. For comparison, humans’ are made up of around 6 million. Additionally, the section of the brain used for smell analysis in dogs is 40 times bigger than the same section in human brains.

    Their unique nose allows them to separate 12% of the air they inhale into a section specifically designed for smelling

    The smell then stays there for analysis, rather than being expelled with the air, as it would in humans. Additionally, their expelled air exits through slits in the sides of their noses, allowing them to sniff continuously. They can even decipher through which nostril a smell entered.

    They rely heavily on smell when communicating with other dogs

    Dogs can even communicate through the smell in their urine. When your little one is stopping to sniff every tree on their walk, their sending and receiving messages from neighbourhood dogs. Likewise, when they meet another dog along the way and stop to sniff one another, they’re getting to know each other.

    They also recognise and love their human’s unique personal smells

    This is why they can get comfort from a t-shirt that smell like you when you’re away.

    Their obsession with socks is most likely because they have such a strong ‘you’ smell.

    They can smell emotions like fear and anxiety

    Changes to the heart rate and blood circulation cause chemicals to surface the skin- this is what your dog can smell. So, they know when something is up and there’s no hiding it from them.

    And as if their superpower couldn’t get any more amazing, they even have a unique organ that allows them to smell and separately analyse hormones and pheromones. This is how they recognise when a dog is ready to mate.

    Just like us, they have their strengths and weaknesses

    They have a super-human sense of smell and expert hearing, we just can’t compete with. And although we have better day vision, their night vision is superior.

    While we’re far better at tasting, we’re missing the specific taste receptors for water and those for meat, like our dogs have.

    Just as we always have been since the beginning of our partnership, we are still a perfect match because of the way our differences complement one another.