Why Do Cats Purr?

Purring is the most common sound cats make. Yet we know less about it than meowing, chirping, chattering, hissing, and growling.

Yes, cats purr when they're content. When yours is curled up in the sun, you may hear a gentle rumble as they breathe in and out. Touch them, and you feel a little quiver. It's almost as if they are sending out waves of calm.

But you shouldn't assume that sound means your cat is in a good mood. Or that it's the only time you'll hear it. Cats purr to communicate other emotions and needs, too.

What if you pick your cat up and hold them? Do they purr because they like it -- or because they are nervous?

Although you'll never know exactly what yours is saying when they purr, research from animal experts, along with considering the situation, lets you make an informed guess.

They Are Happy

Your cat looks relaxed: Perhaps they are on their back, eyes half-closed, tail mostly still. If they are purring, it's safe to assume they are in their happy place.

That noise is a big smile.

They Are Hungry or Wants Something

Some cats purr when it's mealtime. British researchers studied the sounds that house cats make when they're hungry and when food isn't on their minds. The purrs don't sound the same.

When cats purr for food, they combine their normal purr with an unpleasant cry or mew, a bit like a human baby's cry. Experts believe that we're more likely to respond to this sound. They've found that people can tell the difference between the purrs, even if they aren't cat owners.

Kitten-Mother Connection

Kittens can purr when they're only a few days old. It's probably a way to let their mothers know where they are or that they're OK.

Purring also helps a kitten bond with its mother. Mama cats use it like a lullaby.

Relief and Healing

Even though purring takes energy, many cats purr when they get hurt or are in pain. So what makes the effort worth it?

It might simply be a way for a cat to soothe itself, like a child sucks their thumb to feel better.

But some research suggests that purring actually helps cats get better faster. The low frequency of purrs causes a series of related vibrations within their body that can:

  • Heal bones and wounds
  • Build muscle and repair tendons
  • Ease breathing
  • Lessen pain and swelling

This might explain why cats are able to survive falls from high places and tend to have fewer complications after surgeries than dogs.

WebMD Veterinary Reference Reviewed by Amy Flowers, DVM on May 05, 2019

Sources

SOURCES:

Library of Congress: "Why and how do cats purr?"

ASPCA: "Cat Vocalizations."

Humane Society of the United States: "Cat Chat: Understanding Feline Language."

National Wildlife Federation: "Do cats purr? And why are there no green mammals?"

McComb, K. Current Biology, July 14, 2009.

Fauna Communications Research Institute: "The Felid Purr: A bio-mechanical healing mechanism."

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