Why Does My Cat Purr and Knead?

Posted on by Christopher Bern, DVM


Anyone a fan of the TV show The Big Bang Theory? One of the main characters, Sheldon, has a song that he wants sung to him when he’s sick, and it’s an iconic part of the show.

“Soft kitty, warm kitty,
Little ball of fur.
Sleepy kitty, happy kitty,
Purr, purr, purr.”

We all know the signs of a happy cat. Most commonly they will purr, but they may also knead you, the blanket or even the air with their front paws. Why does a cat do these behaviors?

“Making biscuits” goes back to kittens nursing on the mother. As they are nursing they knead the mammary glands with their front paws, which helps stimulate milk production. Nursing on the mother is obviously a pleasant behavior, especially with the milk. Many pet cats retain this instinct, so when they are relaxed and happy they move their paws in a way that mimics that moment of nursing. It’s a mostly unconscious behavior, similar to a person smiling at a pleasant memory.

Purring isn’t understood quite as well. A cat does it mostly when they are relaxed and happy, though sometimes they do it when nervous or uncertain about a situation. How easily or loud a cat purrs is entirely dependent on their individual personality. I’ve had cats that purr while I examine them, even while we are giving vaccines. It actually makes my job more difficult because I can’t hear the heart and lungs over the noise of the purr! Cats have a specialized structure in their throats that causes vibrations as air moves through, and is designed so that they can produce the noise while either inhaling or exhaling. Interestingly, some large cat species lack this structure and cannot purr. A purr is similar in purpose to the contented sigh and smile of a human and is generally a good sign.

About Christopher Bern, DVM

Dr. Bern has been with the practice since 1999 and currently works as the Chief of Staff for the Woodstock, GA hospital. View all posts by Christopher Bern, DVM →

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