Toward the end of February, in honor of Love Your Pet Day, I wrote about the healing power of pets for another publication. Much of the research on pets’ effects on human health focuses on dogs, and I was curious if any researchers had taken the time to look into cats. I was pleasantly surprised to find out they indeed have. In fact, the proof is in the purr.

As some of you readers already know, my cat Alexei came into my life during a time when chronic illness was especially debilitating. As a kitten, he was constantly by my bedside, whether amusing me with our play or comforting me with his cuddles. As my health strengthened and mobility increased, my boy has thoroughly enjoyed more independence, though he is always keeping tabs on his favorite playmate. He seems to have this extra sense for knowing when something is wrong, and I swear his purrs have healing powers.

“Put a cat in a room with a bunch of broken bones – the bones will heal.”– An old veterinarian adage

I was amazed to discover how many studies backed my suspicions. Cats don’t always purr when they are happy, but also when they are injured or in pain. Their purrs fluctuate between 20 to 140 Hz, which is a frequency linked with numerous healing effects, including when muscles and bones best grow and repair.

Cat Sounds that Heal

Scientists at the University of California, Davis suggested that consistent, purring—with frequencies around 25 Hz—can be a healing mechanism, for both cats and humans. Purrs can offset long periods of rest and sleep that would otherwise contribute to bone density loss in both animals and humans.

In 1999, Dr. Clinton Rubin and others discovered that exposure to frequencies 20-50 Hz produces robust striations of increased bone density. Zhonghua Wai Ke Za Zhi, in his work with rabbits, found that exposure to frequencies of 25 and 50 Hz , increased bone strength by 20 percent, stimulating both the healing of fractures as well as the speed at which they heal. Despite differences in size and genetics, this frequency range in cats has been found to have the most therapeutic benefits. The second best frequencies for promoting bone strength are 100 Hz and 200 Hz.

Other studies have found that exposure to frequencies at the range of a cat’s purr to reduce tendon atrophy, decrease muscle atrophy and increase muscle mass relax strained muscles and reduce spasms, heal venous ulcerations and relieve acute and chronic pain in both humans and cats. In-phase chest wall vibration at 100 Hz has also been found to reduce dysponea, or difficulty breathing at rest, in patients with chronic obstructive pulmonary disease (COPD).

The Origin of a Cat’s Nine Lives?

While dogs seem to be the best friend of many Americans, there are approximately 80 millions cats in the U.S. Humans have a long history of relationships with cats, with archeological findings showing domestication of cats might go as far back as the Neolithic Era, according to a 2004 CNN report. Ancient Egypt worshipped the god Mafdet, with the head of a feline, who provided protection of crops for food and shelter from humans. Some of the mythical majesty of cats might have resulted from their seeming ability to have nine lives.

In 1987, Dr. Whitney and Dr. Melhaff documented in the Journal of the American Veterinary Medical Association what veterinarians had been saying for a long time—that mending a cat’s broken bones is much easier to fix and quicker to heal than dogs. The researched observed “high rise syndrome” in cats, where 90 percent of the 132 cats studied falling from high-rise apartments—an average of 5.5, but up to 7 stories high— survived, even with severe injuries. The record height for a cat to fall and live is 45 stories.

According to Elizabeth von Muggenthaler, a research scientist and bio-acoustic specialist, case studies have also found that arthritis, lameness and lung tumors occur less frequently in cats than in dogs.

Literature suggests that, generally, domestic cats have fewer postoperative complications following elective surgeries. They have far less prevalence of ligament and muscle traumas as dogs. Many researchers believe that the purr is a survival mechanism for self-healing.

“Purring could be likened to an internal vibrational therapeutic system, a sort of ‘kitty massage’ that would keep muscles and ligaments in prime condition and less prone to injury,” wrote Paula Peterson in The Cat’s Purr and Sounds that Heal. “Additionally, the purr could strengthen bone and prevent osteodiseases. Following injury, the purr vibrations would help heal the wound or bone associated with the injury, reduce swelling, and provide a measure of pain relief during the healing process.”

The Healing Power of the Purr

The companionship of cats, like dogs, also helps to reduce stress and blood pressure in humans. Both often play a role in cardiovascular events.

A University of Minnesota study found that having a cat around a home correlates with nearly 50 percent decreased risk of heart attack or stroke. After studying adults, ages 30 to 75, for 10 years, researchers found that cat owners had a 40 percent lower risk of suffering a fatal heart attack.

So, it turns out a nice cuddling session with a purring cat can be both healing to the animal and to the human.

“For something to be scientifically therapeutic, it has to be exactly the right strength, loudness, and amplitude,” said Muggenthaler. “However, as a healer, yes, it absolutely can be helpful to sleep with you cat.”

While I couldn’t find studies directly linked to the effect of a cat’s purrs on the central nervous system, I’m a firm believer that my feline is a master healer for neurological disorders as well. And his boundless energy well into adulthood has definitely inspired me to stay on my feet.

But more than that, I appreciate the fact that Alexei has emotionally been there for me through more than seven and half years of great highs and great lows. He’s been a great comfort and source of affection, particularly through the most trying of times. The fact that he still looks at me with any modicum of respect—and an abundance of love—reassures me that he celebrates and appreciates what I mean to him as well.