Most of this is going to come from what I remember from a University assignment a decade ago.
There is scientific evidence suggests that a cats purr can aid healing. A cat’s purr frequency is between 25 & 150 Hertz. google the low end is a similar frequency to the one that medical professionals use in vibrational therapies to promote tissue regeneration.
Known benefits of a cat purring
*Lowering stress — petting a purring cat can calm you
*A cat’s purr can decrease the symptoms of dyspnoea (difficulty breathing) in both cats and humans
*Lower blood pressure by interacting with the cat and hearing the purring sound
*Reducing the risk of heart disease (cat owners have 40% less risk of having a heart attack. Probably because of lowered BP)
*Purr vibrations help to heal infections, swelling, bone healing and growth, pain relief, muscle growth and repair, tendon repair and joint mobility