Thursday, July 19, 2012
The sound of a cat purring on your lap makes you feel like everything is right with the world. One of my cats, Figaro, loves to sit on my shoulder. Actually, he loves to drape himself over my shoulder and hang on with his claws so he won't fall off! Of course he starts purring as soon as he's settled, and how can you evict a contented kitty from your shoulder?
Scientists have been looking into how and why wild and domestic cats purr, and what they’ve discovered is rather interesting. If you're a cat owner, you most likely have figured out that your cat purrs when she's happy, scared, sick or injured. Cats purr even at the end of life which could be anxiety or a state of euphoria. A mother cat purrs while giving birth and when she's nursing her kittens; it's one way she bonds with her kittens and assures them she's not far away. Kittens begin to purr at 2 days old and hum to their mom so she knows they're alright.
When cats are stressed, purring is a way they comfort and reassure themselves that everything is OK – sort of like when we whistle or talk to ourselves as we walk down a dark street alone at night. Purrs are one way to let other cats know they are submissive and not wanting to cause trouble. Older cats use a purr to communicate that they're friendly and want to come closer when meeting other cats.
Members of the cat family Felidae, like the Puma, Cheetah, Mountain Lion, Bobcat and Eurasian Lynx will purr, as well. However, big cats like the Lion, Tiger, Snow Leopard and Jaguar belong to a subfamily of cats called Patherinae and can't purr. Lions can produce a sound similar to purring, but it's not true purring.
At one time, researchers thought a cat's purr was produced when blood rushed through the inferior vena cava which is located around the heart. However, a new theory is that purring is initiated when nerves are activated in the voice box. The nerves send a message to the vocal cords and vibrate them. The diaphragm pushes air between the vibrating vocal cords and creates the purr. A cat's purr is controlled by their central nervous system, and they purr when inhaling and exhaling.
The purr of a cat is at a constant rate and at a frequency of 25 to 150 hertz. Scientists have found an improvement in bone density, and discovered that sound frequencies in the same range can aid in healing. Researchers still don't know exactly why cats purr, but they think it may be a low energy way to stimulate muscles and maintain bone density while the cat is sleeping and during long periods of inactivity. A cat's purr is a voluntary reaction which means they do it because they want to. It may be an instinctive response to us, their kittens or other cats, but it's because they choose to purr to comfort or defuse a situation.
There's no doubt a cat will purr when she's snuggled next to you while you pet her, but scientists also believe it's a means of communicating and a way to help keep their bones and muscles healthy. It's possible that a purr releases natural analgesics (endorphins) that help to reduce pain during the healing process.
Scientists believe a purr may be a form of self healing, and this knowledge may help human patients deal with bone density loss or atrophy of the muscles. It could give NASA scientists insight that could help protect bones and muscles of astronauts during prolonged space travel. That's how important understanding a cat's purr could be!
An interesting side note about a cat's purr – when you take your cat in for a checkup, your vet will usually listen to the cat's heart and lungs to make sure both are functioning properly. Because cats purr when stressed, it's almost impossible for the vet to hear the heart and lungs because their purr is so loud. To stop the cat from purring, the vet will turn on the water faucet which makes most cats stop purring.
For cat owners, listening to a cat's purr is a magical thing we share with our feline friends. And when they snuggle up next to us at night, you can't help but feel everything is alright. A soft hum as they slowly drift off to sleep, safe in your arms. Knowing that your cat is purring because she wants to makes it even more special. The next time you need some TLC, try the healing power of purr therapy. It's good for the body, mind and soul!
Photo by Belal Khan
Read more articles by Linda Cole