You May Think That When A Kitty Purrs, It's Happy. Not Necessarily So, Say The Authors Of A New Book On Cats.

Cats. Even since the ancient Egyptians domesticated them mankind has been captivated by these proud felines. Yet their behavior will perplexes many people.

Enter Dr. Marry Becker, resident veterinarian on US television show Good Morning America, and Gina Spadafori, a pet columnist. Their book - Do Cats Always Land on their Feet? - is the latest attempt to fathom these intriguing pets

Following are some excerpts from the book.

Do Cats Purr Only They're Happy ?

Expert cat observers know that purring isn't just a sound of contentment. Cats also purr when they're injured, while giving birth - even when they're dying.

Purring has been described as something a cat does when he's with a friend or need a friend is happy or is in pain. It seem to be a sound that both conveys and creates comfort.

Here are several more interesting facts about purring .

• While all the smaller cats, including servals and ocelots, purr, some of the big cats can't Lions and tigers can roar and rumble, but they can't purr on the inhale and the exhale the way a little cat can.
  
  Little cats purr, but they can't roar. We think the little guys got the better part of the deal.
  
  

• No one can completely explain the mechanics of a cat's purr. It remains a scientific mystery. Best guess the sound is caused by the passing of air over structure in a cat's voice box.
  
  

• A purring cat can lower human blood pressure and relaxes both the cat and the person petting him. There is even some evidence that purring can help speed the healing process in cats.