I feel quite certain that I have the two reasons why cats purr when they are at a veterinarian’s clinic about to be euthanized. I also think that I have an interesting correlation between the human hum and the domestic cat’s purr.
For years, I took the lead from Dr. Desmond Morris in his book CATWATCHING in which he states that the purr can be given as a signal to “a vet from an injured cat indicating the need for friendship, or as a signal to an owner, saying thank you for friendship given”. In other words, at the point that a cat is being euthanized they purr to seek friendship as a reassurance because they are nervous. Although the don’t know that they are about to be killed but they understand that the general ambience is stressful because it is potentially dangerous.
This helps to explain that the domestic cat purr isn’t just about contentment. It is a multipurpose signal. I would also add that it is a multipurpose health benefit.
Most people by now – thanks to the Internet – understand that the domestic cat purr has health benefits both for the cat and for their owner.
It’s to do with the frequency and at about 100 Hz there are known benefits. I’ve discussed one benefit on a different page which you can read by clicking on this link. On this page I would like to state that the purr reduces stress not only in people but in the cat themselves.
And in reducing stress the purr reduces blood pressure. This is because stress produces hormones and hormones temporarily increase the blood pressure because they signal the heart to beat faster and the blood vessels to narrow.
So, purring reduces stress which is good for the cat. And it is why when you stroke your cat on your lap you also benefit.
And this is where I can see a correlation between purring and humming. When people are nervous, they sometimes hum. Why do people do this? I believe it is because it is an evolved reaction to reduce stress. Nervousness results in stress and therefore you feel uncomfortable. You hum to make yourself feel better. But it isn’t just about feeling better. You are better because humming also has health benefits in the same way as purring has for cats.
For example, it is a known fact that humming can help reduce the symptoms of sinusitis. It helps to open the sinuses and it promotes the production of nitric oxide which has healing properties.
I would suggest, too, that humming reduces blood pressure by reducing stress. And it interesting that bears hum. They don’t purr but they hum.
A Polish veterinarian says that humming is a unique vocalisation produced by all bears except the giant panda. She states that it is a sound closest in form and context to purring.
And in an interesting correlation with the domestic cat purr, bears produce this vocalisation as a form of contentment. It’s a signal from cubs to their mother to tell them that they are content. I suspect that the mother hums in response to provide the same signal. Kittens and their moms do the same when nursing.
This Polish veterinarian also said that she rescued an abandoned bear cub after her mother had been killed by illegal traffickers in Bolivia. The bear cub had lost the will to live and was in bad health. She struggled to bring him back to good health. She did a wonderful job with great patience and gradually, little by little, he found the will to live and gained strength and became a happy bear again.
He began to hum a few times of day to his human mum, the Polish veterinarian. You can see the video below.
Note: This is a video from another website which is embedded here. Sometimes they are deleted at source which stops them working on this site. If that has happened, I apologise but I have no control over it.
There are some cat sounds articles below: