Your kitty shares 96% of its 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 types are known to purr – the speedy cheetah, the rare and endangered snow leopard, and the cougar –– which is also known as the panther, the mountain lion, and the puma.
Roaring, however, is different from purring. Lions, tigers, and other big roaring cats roar to establish territory. For felines that do not roar but purr, purring does not function the same way.
So why do cats purr?
How Does Your Kitty Purr?
A cat’s purr is one of the most mysterious natural occurrences. This is because there is no purring organ unlike with the other vocalizations of various animal species. Veterinarians, biologists, and researchers have always wondered how a cat’s purr is done. There have been various theories regarding the production of this sound.
An older theory on purr production says that the 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 that 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 a certain muscle in the kitty’s voice box, allowing the vocal folds to swing together at one pulse and swing apart at another pulse.
A feline’s purr is also different from other mammals’ purrs. 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 sounds vary between individuals. 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 in 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 could have 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 babies 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 suss out 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 cat’s 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, like when it’s sitting on your warm lap, it may instinctively express its contentment through kneading and purring.
This is also where your pet kitty 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 that have a lot of different meanings. Some of these habits become specialized and modified when a cat establishes a new bond, like with its human.
Such is the case of the “soliciting purr”. This happens when your kitty mixes a purr with high-frequency cries, resembling those of a human baby. The kitty is trying to say “I’m hungry, I want milk” when it purrs to its mom in this fashion.
With you as your cat’s new parent, she has developed and modified her original way of purring. Coupled with a bit of tail rubbing on our legs, she may be saying something like: “I’m hungry. Feed me, hooman.”
Weak as we are to those cute purrs, it is no surprise that our kitties own us and not the other way around.
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 he is hurt, or for very old cats, that she is dying. It could either mean “Please be relaxed and move on,” as if he’s trying to be strong for his human, or he could be saying “I may be harmless and weak, but I am still here.”
On a lighter note, cat researchers observe that some felines purr at their sick or injured kitty companions when they are together. They also do this when they do kitty massage (yes, all 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, her 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 a vibration between the 20Hz and 140Hz range, it is believed that a kitty’s purr can help humans reduce stress, decrease chances of heart attack, lower blood pressure, and help 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 liability during 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 veterinarian trying to follow the kitty’s heartbeat and breathing with the stethoscope. What some veterinarians do—and for some strange reason works—is turn on the water faucet. The running water often distracts cats long enough to make cats stop purring.
Since your baby can express so many things when she purrs, it’s a good idea to take into consideration what she’s trying to say to you.
Is he rubbing against your leg while you are in the kitchen? Is she on your lap making biscuits? Are you both at the veterinary hospital?
Whatever your kitty is trying to say, nothing is more purrfect than a parent’s love in response to their kitty’s purr.