For the purr to exist in different cat species over time,
geographical isolation etc. there would likely have to be something very important (survival mechanism)
about the purr. There is also would have to be a very good reason for energy expenditure (in this
case creation of the purr), when one is physically stressed or ill.
There is also an old veterinary adage still repeated in veterinary
schools which states, "If you put a cat and a bunch of broken bones in the same
room, the bones will heal."
Vibrations between 20-140 Hz are therapeutic for bone growth/fracture healing,
pain relief/swelling reduction, wound healing, muscle growth and repair/tendon
repair, mobility of joints and the relief of dyspnea.
Is it possible that
evolution has provided the felines of this world with a natural healing
mechanism for bones and other organs? Researchers at Fauna Communications
believe so.
clipped from: www.animalvoice.com 
