The Mys­tery of the Purr

There’s a lot go­ing on in your cat’s purr— it's not all hap­pi­ness and it might heal you

Modern Cat - - Contents - BY LAURA DENNIS

There’s a lot go­ing on in your cat’s purr—it’s not all hap­pi­ness, and it might heal you.

Pur­rrrrrrr. The sound alone in­stantly con­jures images of a cat-warmed lap, but hid­den be­tween those vi­bra­tions are fas­ci­nat­ing sci­en­tific facts and even a lit­tle re­main­ing mys­tery.

Sci­ence has yet to be able to say with ab­so­lute cer­tainty why cats purr, but the ob­ser­va­tion that cats purr when they’re happy, re­laxed, and feel­ing good holds true. It’s also true, how­ever, that cats purr when they are hun­gry, hurt, or scared.

While the purr it­self hap­pens dur­ing in­hala­tion and ex­ha­la­tion, a cat’s purr be­gins in the brain. A mes­sage is sent to the la­ryn­geal mus­cles that make up the vo­cal cords, caus­ing them to twitch at a rate of 25 to 150 vi­bra­tions per sec­ond. Th­ese move­ments con­trol how much air passes through the vo­cal cords, pro­duc­ing a purr.

The im­por­tance of the purr be­gins at birth. For new­born kit­tens, their mother’s purr is cru­cial to their very sur­vival. Cats are born blind and deaf but can feel vi­bra­tions, which is where the purr comes in—it leads the ba­bies to mom’s body for both nurs­ing and warmth. When kit­tens find the teats, they do what is known as the milk tread, knead­ing to stim­u­late milk flow. Kit­tens purr in tan­dem with knead­ing, and this combo of be­hav­iours, associated feel­ings of safety and be­ing fed, car­ries into adult­hood. Purring is one of the first things learned by kit­tens—they start purring at just two days old!

Purring con­tin­ues into adult­hood as a form of com­mu­ni­ca­tion with both other cats and peo­ple. Many cats have learned how to use their purrs to ma­nip­u­late their hap­less own­ers to their ad­van­tage at meal­time. Do­mes­tic kit­ties can pro­duce a plain­tive cry sim­i­lar in fre­quency to the cry of hu­man ba­bies and they mix this cry in with their purr. This has the dual ef­fect of both ir­ri­tat­ing their hu­man and also ap­peal­ing to their nur­tur­ing in­stinct, of­ten re­sult­ing in the cat get­ting fed sooner. A study done by the Uni­ver­sity of Sus­sex named this cry-purr hy­brid the “so­lic­it­ing purr.” Clever cats!

It is also com­monly held that cats not only purr out of con­tent­ment, but to self-soothe. The self-sooth­ing purr can be com­pared to the ways that peo­ple some­times soothe them­selves in stress­ful sit­u­a­tions through ner­vous laugh­ter, tears, or other forms of dis­trac­tion, like fid­get­ing. Some re­searchers even con­tend that there may be ac­tual heal­ing prop­er­ties associated with the fre­quency of a purr’s vi­bra­tion. Vets have ob­served cats ly­ing to­gether and purring when one is un­der the weather, giv­ing what looks like purr ther­apy. Ex­perts in sci­en­tific and sports medicine have for years rec­og­nized that vi­bra­tions can cause heal­ing and re­gen­er­a­tion in bones, joints, mus­cles, ten­dons, and lig­a­ments. High fre­quency vi­bra­tions in­crease pro­duc­tion of the body’s nat­u­ral anti-in­flam­ma­to­ries, which re­duces joint pain and swelling and re­pair mus­cles. Vi­bra­tion ther­apy is also used to pre­vent bone loss by con­tract­ing and re­lax­ing mus­cles to stim­u­late the pro­duc­tion of os­teoblasts, the cells that pro­duce bone. Given that purrs vi­brate at 25 to 150 hertz, which is within the range of fre­quency that aids in tis­sue re­gen­er­a­tion and pain re­lief and in­creases bone den­sity, purr ther­apy doesn’t seem like much of a stretch. Re­searchers ini­tially in­ves­ti­gated the heal­ing prop­er­ties of purrs due to the ob­ser­va­tion that cats will purr when in labour, scared, and even right be­fore death. Since the act of purring takes a lot of en­ergy, there must be a rea­son that cats con­tinue to do it when their bod­ies have shut down all non-es­sen­tial ac­tiv­ity due to pain or trauma. Re­searchers in the field of bioa­cous­tics (the study of the fre­quency, pitch, vol­ume and du­ra­tion of an­i­mal sounds as they re­late to be­hav­iour) the­o­rized that the purr must be of sur­vival and evo­lu­tion­ary ad­van­tage. The great news for cat own­ers is that th­ese heal­ing prop­er­ties may work on us. The ther­a­peu­tic ef­fects from purring have been shown to lower blood pres­sure, stress, and prob­lems associated with nerves and anx­i­ety. The com­bi­na­tion of stroking a cat and hear­ing/feel­ing the vi­bra­tions helps us to re­lax. In­cred­i­bly, a ten-year study at the Uni­ver­sity of Min­nesota Stroke Cen­ter found that cat own­ers were a whop­ping 40 per­cent less likely to have heart at­tacks than non-cat own­ers. Time for a purr-in­duc­ing cud­dle ses­sion!

Newspapers in English

Newspapers from Canada

© PressReader. All rights reserved.