Why do cats purr? Is it really a sign of contentment?

Question

Is purring a deliberate act on their part, or just a reflex thing when you pet them? And how do they make the purring noise?

Answer 1

Hi there...The reason is psychological as well as physiological--the two are not mutually exclusive of one another. Cat's purr whenever they feel content, extremely frightened and some will purr when they are dying as well.

How cats purr:
One study determined that purring involves activation of nerves within the voice box. These nerve signals cause vibration of the vocal cords while the diaphragm serves as a pump, pushing air in and out of the vibrating cords, thus creating a musical hum. Some veterinarians believes that purring is initiated from within the central nervous system and is a voluntary act. In other words, cats purr only when they want to.

The other theory is that the sound comes more from vibrating blood vessels than in the voicebox itself. The larger the vocal chords the softer the purr whereas the smaller the louder.
Source: http://cats.about.com/cs/catmanagement101/a/why_cats_purr.htm


The Scientific Reason WHY cats purr:

Some scientists believe when cats purr the frequency of their purring will help heal damaged bones and body organs as well as help heal humans.

All the cats had purr frequencies between 20 Hz and 200 Hz. With the exception of the cheetah, which had frequencies 2 Hz from the rest, all the species had frequencies, notably 25 Hz, 50 Hz, 100 Hz, 125 Hz, and 150 Hz, that correspond exactly with the best frequencies determined by the most recent research for bone growth, fracture healing, pain relief, relief of breathlessness, and inflammation. All of the cats' purrs, including the cheetah, had frequencies 4 Hz from the entire repertoire of low frequencies known to be therapeutic for all of the ailments.

That fact that the cats in this study produced frequencies that have been proven to improve healing time, strength and mobility could explain the purr's natural selection. After a day or night of hunting, purring could be likened to an internal vibrational therapeutic system, a sort of "kitty massage" that would keep muscles and ligaments in prime condition and less prone to injury. Additionally, the purr could strengthen bone, and prevent osteodiseases. Following injury, the purr vibrations would help heal the wound or bone associated with the injury, reduce swelling, and provide a measure of pain relief during the healing process.
Source: http://www.sciam.com/askexpert_question.cfm?articleID=0005CB0D-82FC-1E31-82FC809EC5880000&catID=3&topicID=3.

Answer 2

Cats purr for many reasons, the most obvious is contentment. But sometimes cats purr out of fear or pain, too. You can tell if it is fear or pain by the way they act.
There is a membrane in their throats that closes slightly as air passes through the trachea (almost like the thing that causes humans to snore when they sleep).

Answer 3

Cats purr to show that they are happy, but they will also purr when they are sick or dying.
I asked my Vet this very question one time.

He said that in the wild I cat doesn't dare show that it's ill because they will soon become the prey instead of the preditor..the weak , sick or young are always the first to be attacked in the wild.
So that's why our house cats of today sometimes hide an illness from us, it's part of their nature.

So a very ill or dying cat will purr, not only to hide the fact that it's sick, but also to comfort itself.

Answer 4

for all time. the terrific time for the purrs tho is whilst he has be snoozing and you style of wake him up from a snooze. yet truly he consistently purrs once you puppy him. he's a lover tho. he's likewise a great fan of springing up out, whilst he purrs he's so happy that he merely feels the could desire to lick. that's cute, even though it may get uncontrolled especially situations.

Answer 5

It's considered by veterinary science to be a means of comforting and putting kittens at ease when momma cat returns to the nest. Toms do it too, in order to put momma cat at ease before there are kittens. It's generally considered a sign of comfort and contentment when a cat purrs around it's owner. I had a cat that would purr and rub up against my big puppy. When puppy reacted as a normal puppy would, she'd slap the living crap out of him, and when he backed off and lay shivering in the corner, she'd walk up to him and rub against him and resume purring. They became best buddies - a relationship that lasted until each was a very old critter. Darn cat would purr more around the dang dog than around me! Made me jealous of the dog, lol...

Answer 6

Yes, cats put when they are content. Cats do that as sort of a reflex, with intentions. What I mean is, cats can also purr when they are being threatened by a animal bigger than them, to show pride.

Answer 7

I believe they use it both as a sign of comfort and to comfort. Cats that are sick or dying purr. I think it comforts and calms them. And of course, when we love or stroke them they purr. I wish I could have a purr. How nice would that be?
And I loved Seattle's answer.

Answer 8

I read on-line that they don't know why cats purr - it's a nice sound though!

Answer 9

yes, it is contentment they show without even trying... kind of like laughing at something funny when you don't even mean to.