Why Do Cats Purr?

We know that cats belong to the family Felidae; but did you know that of all the big cats, it is the tiger that has the most genetic makeup of domestic cats? On the other hand, it is the cheetah that shares its vocal prowess.

Your kitty shares 96% genetic makeup with the tiger, but purring is definitely not one of those common traits. In the cat family, you either purr or you roar, but never both. 

Among your frisky feline’s big cousins, only three big types are known to purr – the speedy cheetah, the rare and endangered snow leopard, and the multi-named cougar which is also known as panther, mountain lion, and puma.

cute purring cat

Roaring, however, is different from purring. Roars made by lions, tigers, and other big roaring cats are made to establish territory. For felines that do not roar but purr, purring does not function the same way.

Why, then, do cats purr?

How Your Kitty Purrs?

A cat’s purr is one of the most mysterious natural occurrences in Mother Nature. This is because there is no purring organ, unlike other vocalizations of various animal species. Vets, biologists, and researchers have always wondered how a cat’s purr is done and there have been various theories regarding its production.

An older theory on purr production says that purring sound is a consequence of blood flow turbulence in the kitty’s chest but there is very little evidence regarding this theory. Another theory – the most credible one so far – suggests that a kitty’s purr is the action of the muscles in the larynx and the pharynx combined with a neural oscillator.

As a kitty inhales and exhales, the amount of air passing through the larynx and pharynx alters at high speeds; something which roaring cats and other animals including us are unable to do. How is this possible?

Your house tabby, small wildcats, cheetahs, snow leopards, and cougars have a special timer in their brains that sends about 25 electrical pulses per second – to this a certain muscle in the kitty’s voice box allows the vocal folds to be swung together at one pulse and swing apart at another pulse.

A feline’s purr is also different from other mammals that purr. Rabbits, for example, use their front teeth rather than their laryngeal folds to purr. Elephants don’t use neural signals for muscle control.

Like human voices, cats’ purring sound varies from cat to cat. Some are so low that they can be felt rather than heard, while others are loud enough that you can already hear your kitty purring across the room while you stand at the doorway.

Ancestral Art of Newborn Communication

Your kitty’s ability to purr may have been an ancestral trait that increased the survival of the feline litter. A mother feline developed the purr in order to hide the mewling of the newborn from any nearby predators.

Today, a Mama Cat’s purring leads wayward newborn baby puss to their mother’s teats. Baby cats are unable to see and hear when they are born but they already have their sense of touch which means they are sensitive enough to determine their mother’s vibratory purrs.

In return, the kittens learn how to purr to communicate with both their Mama Cat and their littermates.

Happiness and Contentment

As baby felines develop bonds with their Mama Cat, they also develop the art of kneading which helps release milk from their mother’s nipples. The repetitive actions of kneading, drinking milk, and exchanging purrs with the Mama Cat will eventually become part of your pet puss’ instinct.

As your little tabby grows older, it may be weaned from its mother but the instincts still remain. Whenever it feels happy and contented such as finding itself warmly sitting on your lap – it may instinctively express its contentment through kneading and purring.

This is also where your pet puss differs from other animals. Raccoons, civets, mongoose, bears, badgers, foxes, hyenas, squirrels, tapirs, lemurs, and gorillas may purr due to contentment.

Guinea pigs do the same but an increase in frequency, as well as a combination of tension on their body, may mean annoyance. Cats, on the other hand, purr for many reasons other than expressing happiness.

“Feed Me Hooman”

Kittenhood develops a lot of instinctual habits as well as multiple meanings from these habits. Some of these habits become specialized and modified when a cat establishes a new bond – this time with its hooman.

Such is the case of a “soliciting purr” when your kitty mixes it with cries of frequencies high enough as that of a human baby’s. A kitty would probably say “I’m hungry, I want milk” when it purrs to its mom.

With you as your puss’ new parent, it has developed and modified its original message and way of purring – coupled with a bit of tail rubbing on our legs – it may be saying something like: “I’m hungry. Feed me hooman.”

And with us weak to those cute purrs, it is no surprise why our kitties own us and not the other way round.

The White Flag

Your neighbor’s kitty may purr to your own tabby when they meet. This is another way of saying “Hello! I come in peace.”

A cat’s purr may also mean that it is hurt – and for old cats, that it is dying. It could either mean “Please be relaxed and move on,” as if trying to be strong for its hooman, or it could be a sign of saying “I am harmless and weak, but I am still here.”

Purr Therapy

On a lighter note, cat researchers observe that some felines purr at their sick or injured kitty companion when they are together. They also do this when they do kitty massage (yes, that kneading and purring).

A cat’s purr therapy is not just for unwell companions; they also apply it to themselves, especially when they are in pain, when they feel frightened, or when they feel threatened. This is evident when a mama cat goes into labor. By purring, its body releases endorphins that help ease the labor.

In addition to the release of calming hormones to soothe itself, a kitty’s purr also has the ability to regenerate body cells which includes bones, muscles, and tendons. It is similar to high-impact exercises as well as martial arts training. The consistent pressures applied to the bones and the muscles condition the body again and again; making them stronger.

A cat’s purr in-between hunts is also a way of conditioning its bones and muscles. The vibration helps maintain a cat’s alertness all the time all the while maintaining a strong, spring-like body that is ready to pounce. This kind of vibration conditioning is similar to vibration therapy for patients treated for accidents and bone injury.

This is also why a cat’s purr is believed to be helpful for humans. With its purring within the 20Hz and 140Hz vibration range, it is believed that a kitty’s purr can help humans reduce stress, decrease chances of heart attack, lower blood pressure, and heal bone and muscle injuries.

Purrfect Way to Stop Purring

A cat’s purr may be soothing for us humans but it can be a problem if it involves health checkups.

Because a kitty’s purr can help ease their nerves, cats going to the vet may purr in the middle of a health examination. This can be detrimental to a vet trying to trace the kitty’s heartbeat and breathing with the stethoscope. What the vet does – and for some strange reason it works – is to turn on the water faucet. The running water makes the cat stop purring.


Since your puss baby can express so many things when it purrs, it would be good to take into context what it is trying to say to you. T

Is it rubbing against your leg while you are in the kitchen? Is it on your lap making biscuits? Are you both in the vet’s clinic?

Whatever your kitty is trying to say, nothing is purrfect enough than a parent’s love in response to your kitty’s purr.

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