A nose, ears, eyes and a tongue: our four-legged friends have the same senses as we do. Yet dogs and cats experience the world differently. They see and feel differently, and have a much keener sense of smell, for example. Why is this? Time to explore the world of the senses.
Why does my pet smell more than I do?
Dogs and cats have an incredible sense of smell - much better than us humans. Dogs are the champions: depending on the breed, their noses can have up to 300 million olfactory or scent receptors. Cats have 80 million of them. Our human noses pale in comparison, we have a mere 5 million of them.
Dogs and cats have such a keen sense of smell because they are equipped with a unique olfactory tool: Jacobson's organ, which allows them to analyse scents in the air they've inhaled. Jacobson's organ is located in the mouth, against the palate. To enable odours to enter and flow through this organ, pets open their mouths when they are trying to smell something. That's why your dog drops his stick when he is sniffing a street light – he's taking in all the smells. Fun fact: Jacobson's organ is also present in humans, but it is no longer functional.
Have you ever wondered why a dog's nose is always wet? It's to help them smell better. Tiny glands in the nose help keep the nose wet and tear ducts end in the nose as well. The moisture helps keep the nose clean, which in turn helps the dog absorb smells even better.
The whole process of smelling is pretty different in dogs than in their humans. When dogs are trying to hone in on a particular smell, they will start to breathe faster. The air enters in the front and exits on both sides of the nose. This handy trick means your dog can analyse the difference between their left and right nostril, which means they smell in stereo! This allows them to pinpoint the origin of the scent with fantastic accuracy.
A dog's nose can specialise. You can train a dog to recognise certain scents, and this ability is used, for example, by police, who use dogs to sniff out drugs.
Curious about what dogs smell during walkies? Read more here!
When cats get wind of an exciting smell, they will exhibit what’s called the Flehmen Response. Their face will contort into a grimace, and it will look like they are smelling something mighty awful! In reality, they are directing the scent they’ve picked up to their Jacobsen’s organ. Intact male cats will have this response when they smell lady kitty pheromones nearby, and cats can even use this trick to check out whether another cat is healthy or not.
Clearly, scent is a useful communication tool. And because your cat’s nose is so sensitive, they’ll be super grateful for clean kitty litter and you taking it easy on the air fresheners and incense!
Why do pets have whiskers?
When we humans want to feel something, we use our fingers. Dogs and cats, however, use their faces. Whiskers, the long hairs under the nose, above the eyes and around the mouth, act as touch sensors. The hair follicles of these thick hairs contain small nerves, which send signals to the brain. Whiskers are used to detect air currents, and this helps the animal to learn everything about the size, shape and speed of objects. The whiskers themselves do not contain nerves. That means your pet won’t be hurt when they are cut off, but they would be missing an essential part of themselves that helps them navigate the world safely.
Both cats and dogs have relatively poor eyesight, but cats are also far-sighted, meaning they can’t see objects that are in front of them very well. That’s where their whiskers come in handy! But because their whiskers are so sensitive, your cat may get overly stimulated is they use them too much. This may be happening when your cat throws the food from their bowl and eats it off the floor. They may be doing this because their whiskers are bumping up against the sides of the bowl and it is irritating the bejesus out of them. If you see this happening, try giving them their food on a flat plate or in a wider bowl.
Do pets enjoy the same food we do?
“How in the world can they be enjoying this?” is a question many of us have pondered at the smell of cat or dog food. Dogs only taste 1/5th of what humans taste, and it’s even worse for cats, as they taste merely 1/10th of what their humans do. A taste experience for them is mostly determined by smell and the texture of the food. Cats may have a preference for kibble, or fancy pate and dogs may only eat their dry food when it is mixed with a little of the wet variety. So at least they can be as picky as we are!
Cats use their nose to judge whether food is still fresh enough to eat and if water is suitable for drinking. They can also distinguish which protein is in their food, so they can smell the difference between lamb, fish, chicken and beef.
Dog and cat teeth are typical for carnivores: shaped to catch and rip apart prey. Both dogs and cats are born without teeth. Cats will develop baby teeth after two to six weeks and will get their permanent choppers at three to six months. For dogs, baby teeth come in at three to twelve weeks, and their adult teeth at three to seven months.
Just like humans, cats and dogs can develop plaque and tartar. Be sure to get their teeth cleaned regularly by your vet.
What do cats and dogs see?
Kitten and puppies are born blind. During those first weeks, they are dependent on their powerful noses and sensitive whiskers. Kittens open their eyes at around the seventh to the thirteenth day. Puppies develop this sense just a tad later: they can see around the ninth to the fourteenth day.
To understand what dogs and cats see, we first need to dig up our biology lessons. The retina in the eye is covered with rods and cones. Rods are light-sensitive and make sure you can see in the dark. The cones allow you to see colours. The human eye has three types of cones with which we can perceive red, blue and yellow.
Cats and dogs see the world differently because their retinas have fewer cones and more rods. They only have 2 types of cones, so they can only see the colours yellow and blue. On the other hand, the large amount of rods ensures that their night vision is much better than ours, and they are excellent at perceiving movement. Which comes in handy during the hunt!
Canine eyes are further apart than ours, which means they have a much wider scope of vision. On the other hand, as the scope of vision of our two eyes overlap, it means that humans have better depth perception and are better able to judge distances.
Relative to their bodies, feline eyes are enormous. Cat eyes measure 22 mm in diameter, and at 25 mm human eyes are only slightly bigger! To allow as much light as possible to reach the retinas, kitty pupils can dilate more than ours. There is something else going on with the cat pupils: they are elongated and vertically oriented. This shape ensures that cats can accurately estimate the distance to their prey and to better see movement and depth.
Strengthening the bond
Our dogs and cats experience the world differently than humans because they use their senses in a very different way. They 'taste' their food mainly with their nose, they see better in the dark and explore the world with their whiskers.
Knowledge helps you better understand your pet and gives you the ability to put yourself in their shoes (well, sort of anyway). You can figure out why your cat is not eating their food, or making a mess with it on the kitchen floor, or why your dog insists on sniffing every street light in the neighbourhood. You can anticipate and respond to their needs and strengthen the bond between the two of you!