Cat's Purring

Cat's purring certainly did have its main advantages over other animal species, throughout animal history. Nonetheless, most feline species also produce some sort of purr-like vocalized sounds. In the case of domestic cats, purring can be noticed especially when a female cat is nursing her babies or when humans interact with cat through feeding, stroking or petting.

We usually assume that the purring of a cat is a sign of increased pleasure and contentment. But we may not always be right because we may be judging things from our human perspective. In fact, although cats most often use purring to communicate with their kittens, to express their gratitude or sense of well-being towards their owners, cats may also purr when they feel pressured or stressed. This may also happen during a veterinarian visit or when the animal is recovering from an injury, from an illness or a surgery. As we can see, not all the purring cats are pleased or happy with their current situation. The question why cats purr is still under debate, and researchers are still investigating the issue.

Another purring-related issue is how cats manage to produce these sounds. Thus, scientists have proved that cats can produce the purring sounds by laryngeal and diaphragmatic muscles' intermittent signaling. Both during their inhalation and exhalation, cats have a consistent purring frequency between 25-150 Hertz. The results of several investigations have attested that sound frequencies of this range can in fact improve the density of bones and they can enhance the healing processes.

Thus, cat's purring frequencies are strongly related to the capacity of healing muscles and bones. And because of that, this feline inborn quality may prove to be of use to us humans. Especially if we come to think of astronauts and their muscle atrophy and bone density loss problems when exposed to long periods of zero gravity exposure. In that situation, astronauts' muscular-skeletal systems are deprived of the normally experienced physical activity stresses, including the routine of sitting or standing, which demand human strength for controlling one's posture.

Cats are adapted to preserve and re-charge their energy through long periods of sleep and rest. Because of that, purring may in fact be a mechanism that requires low energy to stimulate bones and muscles. Because they are so durable, cats are said to have "nine lives" (or in Romanian culture, the saying is "a cat has seven lives"). There even is a veterinarian legend saying that cats have the power to reassemble all their bones if they are left in the same room with all other body parts. The roots of this cat mythology may be found in cat's act of purring.

Also, as compared to other domesticated animal species and pets, the domestication of cats happened quite recently. Due to this late domestication, cats have less bone and muscle abnormalities than dogs, which have been more strongly selected by humans. Cat's purring may in fact help them ease the osteoporotic or dysplastic conditions that are quite common of the dog species. And although we may feel tempted to consider that cats purr when they are happy and healthy, it's perhaps closer to the truth to acknowledge the fact that cats may be purring in order to communicate and heal themselves.

At any rate, cats and their purring may indeed have a therapeutic effect on humans, helping them heal faster and better. We could mention in this respect Aaron Katcher, an American psychiatrist who in 1982 proved in front of the camera how petting a cat can help release anxiety, arterial pressure, i.e. it can diminish the risk of heart stroke. Dennis R. Ownby, who is responsible with the allergological and immunological section of the University of Georgia, US, concluded after a 7 years study that daily interaction with cats humans get exposed to some molecules which are reputed for the efficient protection of the immune system. Cats are also said to have antidepressant effect on us humans but they don't send us any positive energy, all they do is liberate humans from their negative energies, anxieties and stress. They are a kind of emotional sponges, absorbing our bad vibes, in a way, without replacing them however with good vibes.