The sound of a cat's purr brings comfort to us. The rattling sound coming from this adorably, plush animal soothes our stressful lives. But do you know why a cat purrs? We have always associated that when a cat purrs it's because they are content and happy, but that's not always the case!
I always grew up with cats. One of my favorite things about them was when they purred. I once had a cat named Pepper, who would purr for what seemed like hours on end. He was always a happy cat. He loved everyone and whenever he would head butt you, he would purr. I ALWAYS thought he purred because he was a happy cat, but I was so wrong!
This cat is clearly throwing some happy purrs.
See, cats purr for a variety of reasons. They mostly purr because they are happy. That is mostly right. But have you ever seen a time where a cat has purred during an uncomfortable situation? It's actually quite normal. In the book written by the famous cat behaviorist Pam Johnson-Bennett, she states that momma cats purr during labor to have ease the pain of childbirth. The purring sound comforts them in this time of need.
Cats can also purr because they are shy, nervous or even scared! Feral and/or scaredy cats will purr to help soothe the uncomfortable situation. So, the next time you take your cat to the vet and they can't stop purring, it's very likely that they don't want to be there and are purring to help control the situation. (I mean seriously, who loves going to the doctor?)
The purr sound comes from the laryngeal and diaphragmatic muscles in the cat's body (located in the throat region) along with a connector in the brain called the "neural oscillator" (say that three times). The brain tells the muscles in the throat to start vibrating. When cat's purr, endorphins are released. The endorphins helps soothe the cat and makes them feel good.
So endorphins can be released when a cat is happy or when they are sad/nervous/angry, etc. Never judge a good ole purr by it's cover - you could be petting a very angry pussy cat :)