The essentials
- Cats have a dual scent mechanism that works like a superpower — The two separate parts of a cat’s odor detection system, the nose and vomeronasal organ, work together to pick up things neither system could on its own.
- Scent is a cat’s most reliable tool for receiving information — Cats use their powerful sense of smell to socialize, mate, hunt, and explore the world around them.
- A cat’s sense of smell is far more advanced than ours — The human nose contains about 5 million olfactory receptors that detect aromas, while a cat’s nose contains up to 200 million.
- Cats have an even better sense of smell than dogs — Cats are able to smell and identify a larger variety of scents.
How does a cat’s sense of smell work?
Like other animals, cats have regular olfactory (scent) receptors that pick up the aromas in the air. They also have a second “nose” hidden in the roof of their mouth called the vomeronasal organ (aka Jacobson’s organ). The receptors in this organ pick up things that the scent receptors in a cat’s nose can’t. Scientists think the information processed by this special organ serves as a cat’s sense of smell and taste.
Ever notice your cat scrunching its face or curling its lips? Don’t worry, they’re not getting aggressive. You’ve probably just witnessed a scent-sucking mechanism called the Flehmen response. This isn’t just unique to cats. Many animals use this behavior to investigate smells by opening the tiny ducts behind their incisors that lead to the vomeronasal organ.
What does a cat use its sense of smell for?
With almost 40 times more odor-sensitive olfactory cells than humans have, it’s no wonder cats rely so heavily on their sense of smell. They use it for all kinds of things, including the following:
Sniffing out danger
A powerful sense of smell is one of the best hunting tools in a cat’s arsenal. Outdoor cats use it to determine if other cats have been in the area or if any mice are lurking in the alley behind their house. Indoor cats use it to identify unfamiliar animals, new people, and changes in their environment.
Determining if food is safe to eat
Cats’ powerful scent receptors can determine if food is fresh or spoiled.
Communicating with one another
Cats also use their sense of smell as a chemical communication tool. When meeting other cats, they use physical greetings — like a gentle head bump — to release pheromones from glands in their faces. These pheromones tell cats a lot about each other, including their sex, how healthy or sick they are, what they like to eat, and what sort of mood they’re in.
Locating a mate
A cat’s vomeronasal organ mainly communicates with the part of their brain that deals with mating. It identifies pheremones to provide male and female cats with the information they need to determine if a member of the opposite sex is available. Female cats in heat exude a powerful pheromone that male cats can smell up to a mile away. Females also use their sense of smell to scope out a preferred mate by sniffing males’ territorial markings.
Setting territory boundaries
Cats mark places they live and visit with scent glands on their feet, cheeks, face, and tail, as well as with urine. This signals “ownership” to other animals and lets them know the cat was there long after they’ve gone. Cats also mark their territory when they feel stressed or threatened and to advertise sexual receptivity and availability. Marking can occur when your cat senses other cats in the vicinity, either outdoors or among the other cats that live in your home.
Common nasal issues you might experience with your cat
- Sneezing. Cats can sneeze for all the same reasons humans do. Upper respiratory infections (URIs) caused by bacteria, fungus, or viruses, irritants, allergens, nasal masses, and foreign bodies in the nose are all common causes of sneezing in cats.
- Nasal polyps and tumors. Nasal tumors are uncommon in cats, accounting for just 1%-2% of all feline tumors. However, most nasal tumors are malignant, the most common being lymphoma and the second most common being carcinoma.
- Nasal infections. Viruses are the most common cause of sudden nasal infections like rhinitis and sinusitis in cats. Rhinitis is inflammation of the mucous membranes, while sinusitis is inflammation of the lining of the sinuses. The two commonly occur together as rhinosinusitis.
- Loss of smell. Loss of smell is most common in older felines. This issue can be temporary in the case of a respiratory infection or permanent, which can occur as a result of trauma or cancer of the nasal structures. Cats that permanently lose their sense of smell adjust over time but tend to require some help along the way.
Dogs vs. cats: how their sense of smell differs
While dogs certainly have an impressive sense of smell, a cat’s sense of smell is even more powerful.
This has a lot to do with V1R, the scent receptor protein thought to be responsible for giving mammals the ability to distinguish one scent from another. Humans have two forms of this protein, dogs have nine, and cats have 30, allowing them to identify and differentiate between a larger variety of scents.
Cats’ receptor-rich noses – each packing an average of 200 million individual receptors – also make up for their lack of taste buds. In other words, cats smell their meals instead of tasting them. Dogs, in contrast, are thought to be able to taste sweet, sour, salty, and bitter flavors, much like us humans.
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Frequently asked questions
Do cats have a better sense of smell than dogs?
In general, cats do have a better sense of smell than dogs. However, there are some dog breeds, like the beagle, basset hound, Belgian Malinois, German shepherd, and bloodhound, that have more nasal receptors than the average cat.
How far away can cats smell?
It’s hard to give a precise answer to this question. One study found that domestic cats could find their way back home from a distance of 1.5 to 4 miles, so it’s safe to assume they can at least pick up scents from that distance.
Do cats recognize their owner’s scent?
Because our resting faces look the same to cats, they learn to tell us apart using sound and smell instead of sight. Every human has a distinguishable scent to cats.
Do cats recognize each other by smell?
Cats can recognize each other by smell, but it’s not clear for how long. Littermates exchange scents early in life to recognize each other should they get separated. Older cats use physical greetings to release pheromones from glands in their faces and learn more about each other.
How strong is a cat’s sense of smell?
A cat’s sense of smell is incredibly strong. The average cat’s nose contains 40 times more odor-sensitive cells than our own noses and twice as many scent receptors as the average dog’s.
Can cats smell disease?
Yes. Like dogs, cats’ acute sense of smell gives them the ability to sniff out chemical changes in both humans and other animals caused by a disease.
