Myths Debunked: Cats Purr Whenever They're Happy
Purring is one of the most special elements of a cat, as far as most humans are concerned. Caressing a purring pet has proven to relax the one doing the stroking and lowers the blood pressure too. A purring cat or kitten is sure to bring a smile to the face of any human, young or old, and cats have made a real difference in the lives of those in nursing homes or other institutional settings, just by the simple act of being a cat.
But careful observers of the cat know that purring isn't just a sound of contentment. Cats also purr if they're injured, while giving birth - even when dying. British zoologist Desmond Morris has observed that purring is "a sign of friendship - either when the cat is contented with a friend or when it is in need of friendship - as with a cat in trouble.
Our friend Dr. Margie Scherk, a board-certified specialist in feline health, likens a purr to the human smile. You smile when you're happy, to be sure, but you can also smile when you're nervous, or even when faced with a threat. In the latter two situations, it's kind of a "Hi, I'm a nice person, don't hurt me" sign. And the same is true with purring.
Kittens start purring even before they open their eyes, rumbling while nursing in what must be a reassuring sound to their mother, who is likely purring herself.
Our cats have one thing to lord over the "King of Beasts" and other more formidable felines. A cat can purr, but the lion can't, nor can any of the other big felines. The tiger can rumble a friendly greeting but only on the exhale. No big cat can get his motor running the way our household kitties can, purring constantly as effortlessly as breathing, both in and out. To even things out, however, big cats possess the ability to roar. On the whole, the little cat got the better part of that deal, at least where humans are concerned.
Although the experts are pretty clear on why cats purr, they're not yet certain as to how. The most common explanation has the sweet sound originating in the voicebox, with what are called the vestibular folds, or false vocal chords. The passing of air across these structures is thought to produce the purr all cat lovers adore.