Why Does My Cat Purr?

It’s not just because he’s happy ...

why do cats purr

You might notice your cat purrs when you’re petting him or he’s rubbing up against you.

And you know he’s purring because you can feel the telltale vibrations and hear that low rumbly noise he makes — but what exactly does it mean when your cat purrs?

The Dodo spoke with Dr. Amy Learn, a veterinarian at Animal Behavior Wellness Center in Richmond, Virginia, to find out why cats purr.

How do cats purr?

Your cat purrs by using muscles in his larynx (aka his voice box).

“The noise results from activation of the deep laryngeal muscles, which results in partial throat closure and increased pressure across the opening for very brief periods of time in segmented patterns,” Dr. Learn told The Dodo.

Those brief, segmented patterns explain why your cat’s purring sounds and feels like muted vibrations.

Your cat’s purring might sound a little different from time to time, which is actually pretty normal. Those changes have to do with the reason why he’s purring.

“The variation and tone are based on the cat’s emotion or interest,” Dr. Learn said. “Some purrs are even inaudible.”

Why do cats purr?

While most people think cats only purr when they feel content, there are actually a few reasons why your BFF might be making that noise.

He’s communicating

The very first time your cat purred in his life, it was probably because he was trying to talk to his mom.

“Kittens begin purring by 2 days of age,” Dr. Learn said. “This vocalization starts as a means of communication between the mother and her kittens, then evolves by the third week of life into a greeting or request.”

Your cat might purr to try to communicate with you, too, particularly if he wants something.

“By 3 months of age, the kitten can use the purr to request food or attention,” Dr. Learn said.

He’s happy

That being said, there’s a reason why pet parents identify their cats’ purring as a sign of happiness — it often is just that.

“Cats that purr may do so like a human smile,” Dr. Learn said.

He’s not feeling great

Sometimes, however, that very expression of happiness could also be a sign that your cat’s feeling sick or upset.

According to Dr. Learn, purring can be a sign of stress, fear or anxiety. And other times, it could indicate that your cat’s dealing with some sort of medical condition.

“Cats can also purr during a chronic illness or preceding death,” Dr. Learn said. “This may be associated with a feeling of delirium or euphoria related to natural opioid release.”

He’s trying to heal himself

Some research even seems to show that domestic cats purr at a specific frequency — 25 and 50 hertz — that could help with bone growth and healing.

The theory is that when your cat’s body vibrates at such a low frequency, those vibrations can heal tendons, build muscle and reduce swelling.

It’s hypothesized that vibrations at those frequencies can even minimize pain and make your cat’s breathing easier.

So if your cat is purring but seems a little bit off, give your vet a call just to be safe. Otherwise, your cat’s probably purring because he’s loving those pets you’re giving him, or even wants a little extra attention.

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