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Small Cats (A - E) | Small Cats (F - M) | Small Cats (O - S) | Big Cats | How Cats Purr

How Do Cats Purr?

Scientists believe that process of purring is oscillatory, meaning that sound swings back and forth with a steady, uninterrupted rhythm, taking place through intermittent signaling of the vestibular folds (found behind the cat's larynx) and diaphragmatic muscles. But, there's no exact way of knowing how cats purr. What is known is that purr frequencies have been measured between 20 Hz and 200 Hz.

Do All Cats Purr?

All small cats purr, and only three species of big cats (the cheetah, clouded leopard and Bornean clouded leopard) can make a true purring sound. The other big cats purr, but they don't make a true purring sound, because they only purr when they exhale. The resulting sound is more like a chuffing or coughing sound, rather than the constant vibrating motor-type sound you hear from small cats and the purring big cats. It's also believed that big cats can't purr while meowing, growling or eating, like small cats can.

Click the "play" buttons below to hear the difference between a big cat purr and a small cat purr.

Tiger Purr

Domestic Cat Purr

Why Big Cats and Small Cats Purr Differently

The hyoid bone has an elastic segment in the snow leopard and cats in the Panthera genus (tigers, lions, jaguars and leopards), but is completely ossified (inflexible and hard all over) in small cats, and the three purring big cats. The elastic segment allows the Pantherine cats to roar, but prevents them from purring in the same way small cats and the purring big cats can. Snow leopards have the same hyoid bone structure as Pantherine cats, so they purr in the same chuffing/coughing manner as the Pantherine cats. But, they can't roar due to the under-development of the fibro-elastic tissue that forms part of the vocal apparatus.

Note: most people think that pumas are purring big cats, but they aren't big cats. They're actually the biggest species of small cat. Thus, they purr the same way small cats do. The only difference is that pumas purr louder due to their size.

Do Cats Purr When They're Happy?

Small cats purr when they're happy. But, it's not the only reason. Mother cats purr while giving birth. A kitten is able to purr by the second day of life, and although it can't meow and nurse at the same time, it can purr and nurse. And, mother cats usually purr back at them, to reassure them. Cats will also purr if they're injured, and 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." In this respect, it's similar to how people will not only smile when they're happy, but also when they're nervous or faced with a thread. Both are a way of saying, "please don't hurt me; I'm not a threat."

Purring is also apparently good for healing, which is why cats purr when they're injured. Purring causes vibrations that are known to be therapeutic. The aplitude and frequency of the cat's purr are good for healing muscle, tendon, and ligament injuries, as well as for muscle strengthening and toning. The vibrations from purring are good for any type of joint injury, wound healing, reduction of infection and swelling, pain relief, and relief of chronic pulmonary disease. This was found out by past veterinary research and is being taught in veterinary schools today. New research has shown that purring releases endorphins (the brain's morphine-like chemical). Since endorphins are released under circumstances of pain and pleasure, this would explain why cats purr when they're happy, stressed, injured, in pain and even close to death.

Most people know that big cats will purr to communicate a greeting or an apology. But, studies of big cats in various environments show that big cats also purr for many of the same reasons smaller cats do. Even though the volume of the big cat's purr is much louder, the amplitude and frequency are as therapeutic as a small cat's, which is why they'll also purr when they're injured or distressed like small cats do.

Small Cats (A - E) | Small Cats (F - M) | Small Cats (O - S) | Big Cats | How Cats Purr