Why Cats Purr

One of the most comforting sounds and sensations we can experience is the purr of the cat. But it is also one of the most mysterious of all feline traits.

With all the advances in technology in the last 100 years, one might think it odd that we have yet to solve this one. But the problem is we can't study the purr under ordinary circumstances. For instance, we can't take a cat apart to watch the process. We can't perform any tests that are painful, confusing or irritating, because the cat won't purr unless it wants to. And usually they only want to purr when they are happy and content. There are exceptions to this, which I'll explain in a moment.

Still, some scientists and investigators have managed to catalog certain traits of the purr itself and have come up with some plausible conclusions. They just haven't been able to prove them yet.

One theory is that the mechanics of the purr involves a secondary set of membranes situated near the vocal cords. Others feel it is a vibration of a particular network of blood vessels in the throat and chest.

Several articles have been published recently and appear in authoritative publications. For example, Scientific American: Why do cats purr? offers some interesting facts about purring, including the very plausible theory that the vibrational frequency may be related to a cat's ability to heal more quickly than other species.

The reasons behind purring are as varied as the theories for the mechanics of the process. Obviously, contentment and happiness must be one of the reasons for a cat to purr, but observations from others, as well as from personal experience at our cat shelter, prove that purring often accompanies times of extreme stress - even just prior to death. Perhaps they are trying to comfort themselves, or even to "speed heal" themselves.

Mother cats purr during the birth process and certainly during the nursing period for the benefit of her kittens. Since kittens are blind and deaf at birth, for at least the first week or more, the vibration from the purr may assist the babies in finding and staying close to mom. Kittens also purr, perhaps to let mom know they are near, too, and to encourage her to relax to facilitate the nursing process.

Of course, these are all theories, but they are based on many thousands of observations over the centuries, so perhaps much of it is true after all.

Copyright 2006 - 2007 - RJ Peters 
Dr. R.J. Peters, a retired physician, established an animal rescue shelter in 2002. She has worked with hundreds of dogs and cats and shares much of what she's learned, at The Problem Cat.