It is all in the Purr

Is there anything more enjoyable than hearing your cat purr as they lie curled up in your lap – it is such a satisfying sound! But how does this special sound of contentment happen?

A cat does not have a particular body part that produces the purr but rather purring involves the rapid movement of the muscles of the larynx (voice box), signalled from a unique “neural oscillator” in the cat’s brain, combined with movement of the diaphragm (muscles at the base of the chest cavity). These muscles move at 20-30 times per second.

Not all cats can purr. Most of the big cats like lions, tigers and jaguars, who roar, don’t purr.

As the cat breathes, the air touches these vibrating muscles and the purr is produced. Purrs are fairly unique to each cat, some higher or lower pitched and some faint and others loud. For those of us ruled by our feline companions, we will know they also have a purr/meow combination for when they would like attention, especially for food etc. This special “purr” is known as a solicitation purr and is part purr, part meow. Our response is similar to a parent response to a baby crying – our cats have evolved to take every advantage of domesticated life!

It is worth noting that the cat purr can be a sign of several different emotions depending on the situation. When your cat is being stroked and is relaxed, the purr emitted is a sign of contentment. Kittens are born blind and deaf, remaining so until they are around two weeks old. However, they begin purring after just a few days, primarily to let their mothers know where they are, and to attract their Mum’s attention at feeding time.

The purr can also be a distress or pain response. In these instances, the theory is that cats are using purring as a way to soothe themselves the way a child would suck their thumb.

Some theories indicate that purring also helps cats get better faster after illness or injury. The low frequency purr causes vibrations in the body that help to reduce pain and induce healing. Many cats may purr while giving birth and this may lend evidence to the theory that this purr helps cats to repair and soothe themselves and the kittens through the process. 

Some domestic cats simply don’t purr and we don’t know why. It could be due to anatomical differences but not purring can be completely normal for some cats. However, if your cat previously always purred and suddenly stops, this may indicate that something has happened to stress your cat or that they are injured/unwell. Stressful events like home extensions or the introduction of another cat can cause the reduction in purring. Sometimes specific medical issues causing inflammation or changes in the mouth, pharynx, larynx and trachea, may cause pain when purring or affect the vibration, preventing purring.

While we still have lots to learn about the cat purr, I think we can all agree that the purr elicits a powerful physiological response in us humans – we feel calmer and happier around that purring cat!

Contact Otaki Vets if you notice a change in volume or frequency of purring. Give us a call on 06 364 6941.