Cats are so cool. Like their canine counterparts, they provide us with companionship, but they are vastly different in so many ways. One of the coolest things about cats is their ability to purr. It’s a sound that has the unique ability to not only make the cat feel content, but also any person in the general vicinity.
But why do cats purr? And how do they make that unique sound? Read on to find out.
Duh, because they’re happy
Well, yes and no. Certainly in the vast majority of cats that lovely vibrating sound is one of happiness, and it indicates that you’re doing it right, and your cat is pleased with life in general. Studies tell us that kitten purr to reassure the mother that a.) it’s still there, and b.) it’s all good. So it’s likely more a sign of general contentment.
But as a vet I can think of many times that I’ve stuck my stethoscope up to the chest of a sick cat and heard what??? Purring? Because of this many people theorize that cats not only purr when they’re happy and content, but also as a sort-of soothing mechanism that makes them feel better.
How a purr is different from a meow
Anyone who has a dog can tell you that they have different barks for multiple occasions – they’re glad to see you, that super-shifty UPS guy is here again (let’s get him!), throw the ball for me, etc. We don’t get much in the way of vocal communication from our felines, other than purring and meowing.
Purring is vastly different in its mechanism than meowing in that it occurs during both inhalation and exhalation of breath – kind of a continuous cycle. Cats make the purring sound with the muscles of the larynx, which is often called the voice box in people. The muscles are used to separate the vocal chords, and when air is passed over them during inhalation and exhalation, purring results.
Big cats do it too
Some of the big cats purr just like housecats do, but not all. Bobcats, cheetahs, and pumas all purr, but lions, tigers, and jaguars don’t.
Not all purrs are audible
Most cats can produce a purring sound, but not all of them produce audible purrs. The next time you’re snuggled up with your cat that you think is non-purring, put your fingers over his throat. You’ll likely feel a vibration, which is really just his way of purring without making a sound.
If your cat doesn’t purr, don’t panic. Some of them just…don’t. If it’s always been that way, and everything else about him is normal, it’s likely just the way he is.
How come my cat lost his purr?
A cat can lose its purr if there is trauma to the vocal chords or to the nerves that control the laryngeal muscles. How would this kind of trauma happen? If a cat has serious and long-standing upper respiratory disease, there can be scarring that is sufficient to alter the function of these nerves. Very rarely, cats lose their purr after anesthetic procedures, because the tube that is put into the trachea to provide oxygen and anesthetic gas causes a bit of trauma. Usually the loss is temporary, but if the damage is significant enough, it can be permanent.
I might be imagining it, but my cat’s purr sounds different
It’s likely that you’re not imagining it. With a change to structures in the region of the larynx, you can start to hear a difference in the way your cat purrs and/or meows. Pay attention to these subtle changes, because they can indicate enlargement of the thyroid gland, which most commonly occurs with the hormonal disease hyperthyroidism.