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Pet Behavior - Feline Behavior
How and Why Cats Purr

By Susan McCullough
Did you know that, like vibrating piano strings, the
sounds and vibrations your purring cat emits are in
perfect musical harmony with each other? Those positive
vibrations form the basis of one of the most soothing and
pleasurable means of communication in the entire animal
kingdom. Usually, your cat is telling you, “I’m feeling

In addition to the messages purring can send to you and
others, it offers physical benefits to both felines and the
lucky people petting them.
Purring Mechanics
Despite all of our high-tech advancements, the anatomical and mechanical roots of your
cat’s purr aren’t entirely known. “Theories are that it is a vibration of the larynx [voice
box] or diaphragm,” says Elaine Wexler-Mitchell, DVM, author of Ask the Vet about Cats
(BowTie Press 2004). “The vibration is stimulated by neural messages sent from the

Cat behavior expert Amy Shojai, author of PETiquette: Solving Problems in Your Multi-
Cat Household (M. Evans 2005), says that purring results when laryngeal muscles
alternately open and close the glottis [the combination of the vocal chords and the
space between the folds], causing a sudden separation of the vocal chords. The sound
is due to the sudden buildup and release of pressure from the inhaling and exhaling of

Purring Messages
Even though your cat purrs the same way no matter what’s going on, the circumstances
surrounding the purring determine what your pet is communicating. Often it’s
contentment -- a reflection of your cat’s perception that all is right in its world. However,
those feline rumbles may be sending a different message in some situations. These
messages include:

“I’m a nice kitty” Some cats may purr to signal to other cats that they’re friendly and
want to come closer to them. In certain situations, a cat purrs to signal to another party
-- feline or human -- that it poses no threat to that individual. If your cat purrs while
being handled at the vet and also head bumps with forward-facing ears, she’s probably
signaling that she poses no threat and feels minimal fear.

“I want to reassure myself” A cat that’s feeling nervous or upset may respond by
purring. “Cats that are gravely ill will purr,” notes Wexler-Mitchell. “Purring in this
situation may provide some comfort.” Dying cats are also known to purr, as are cats
giving birth.

“I’m OK, you’re OK” Many experts believe that kittens, which can purr when they are
only 2 days old, do so to signal to their mothers that everything is fine. The mother not
only hears the sound of the kitten’s purring but also feels the vibration. Mother cats are
likely to purr back to their offspring in the same spirit of reassurance.

Physical Benefits
While mother cats and kittens use purring to let each other know that everything’s all
right, purring also helps ensure the kittens’ survival. That’s because newborn kittens,
like many newborn animals, can’t see or hear. However, they can feel the vibrations of
their mother’s purring, and those vibrations can guide them to their mother and enable
them to nurse. The kittens then continue to purr while they nurse, as the vibrations
reassure the mother cat that her babies are where they’re supposed to be and doing
what they’re supposed to be doing.

Researchers have additionally found that purring may have healing properties too.
“Interesting studies indicate that purrs help speed healing, particularly of broken
bones,” notes Shojai. Scientists have also found that low-level vibrations, such as those
in feline purring, may help strengthen bones as well as muscles, ligaments and tendons
-- which may account for the relative rarity of muscle and bone diseases in cats.

Finally, purring has a calming effect. Because of this quality, cats often serve as therapy
animals in health care facilities, especially nursing homes. But a person doesn’t need to
be sick to benefit from feline therapy. “Nothing can be quite so therapeutic as a purring
kitty on your lap,” says Shojai. “My cat, Seren, seems to know when I need this sort of
purr therapy. Petting her calms and reduces my stress.”

Do you need a break from everyday pressures and hassles? Hang out with your purring
kitty and feel those stresses melt away.

By Susan McCullough for The Daily Cat