Cats and purring

No one knows for sure why cats purr. Many people believe that cats make this unique noise as a sign of contentment, and this may certainly be the case. Many cats purr when their owners pet them. They also purr during other moments, though when they feel anxious or when they have been injured, for instance. Certain scientists have even suggested that the low sound frequency of a cat's purring (within the range of 100 Hertz), can stimulate the growth and healing of bones and body tissue.

How cats purr has also been a subject of much debate for some time. One theory states that the sound is an effect of air moving through the animal's lungs and the subsequent vibrations in the diaphragm. Another belief is that purring comes from cat's abdominal region. Yet a third possibility suggests that purring emanates from the inferior vena cava, the vein that carries blood to cat's heart from the lower part of his body. The most recent research, however, points to the laryngeal muscles (or voice box) as the source of the sound.

No matter how or why, virtually all cats purr. Kittens begin purring when they are newborns, continuing the sound even as they nurse. Perhaps what makes purring so curious is a cat's ability to maintain the sound as she breathes in or out unlike meowing, which is only done when the animal exhales. Although it may seem like an involuntary reaction, purring is something a cat chooses to do, much like everything else this especially independent species does.

Cats in the throes of giving birth will continue purring throughout their deliveries, as will those on the verge of death. If the purpose of this sound were merely to express pleasure, purring would not occur at these difficult moments. Whether your cat is purring because he is happy or for another reason entirely, it is undeniably a multi-faceted gesture. Your cat may even purr for reasons unique to him.