We often identify cat purrs as an expression of pleasure or contentment, but this does not explain why cats also purr when they are injured, frightened or even giving birth.

Cats often purr while under stress. They purr at a frequency between 25 and 150 Hertz. This range of sound frequency can improve bone density, healing of tendons, ligaments and muscles and provide some level of pain relief.

That explains why cats seem to be more resilient from an injury. Cat's mythology of having the ability to reassemble their bones after an injury and having nine lives may be based on the power of purring. The survival rate of a cat that plummets from an extraordinary height is measured to be around 90% according to veterinary medicine researchers. Also, cats experience less complications after a surgical procedure than many other animals such as dogs. Compared to dogs, cats tend to heal faster and more easily.

Tracie Steger, Giggle-Blizzard's staff shares her story about her cat's amazing recovery:

I recently had an opportunity to learn even more about this when my cat, giggle-blizzard, got lost and then was seen getting hit by a car.  It took him Five days to crawl 1.2 miles on two back broken legs to get back home.  From the time he crawled through the front door until the moment he was put under  sedation for surgery the next day, Blizzard continually purred.

In the middle of the night, Blizzard’s purring was so loud that it actually woke me up.  That’s when I noticed he was sound asleep, yet still in full purr-mode.   And then it hit me, he was purring to cope with the pain!   (And to think - I just figured his purring meant he was happy to be home!)

I asked the orthopedic veterinarian at my clinic about it the next day. He said that the vibration of his purr created a frequency sound wave that helped reduce the pain he felt as his muscles were contracting all that time from the broken bones.  He also told me that broken bones heal faster in cats than other animals, due to their purring abilities.

I asked him if there were such a thing as a “purr machine” set at a frequency that could aid in the healing of fractures in dogs or humans.  He just laughed it off, but, seriously, could that work?

Since cat purrs are able to improve healing of bones and muscles, scientists believe that these sound frequencies can also aid people with problems such as bone density loss or muscle atrophy. Many women especially those in the mid-age suffer from osteoporosis (bone loss). Cat purrs can potentially be a method to help women with such ailments.

image via fofurasfelina