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PETS
2007, August 30, Thursday

The Truth About Cats and Dogs (1/2)
Interesting facts you never knew about your favorite pets

Q: Do cats really need to drink milk?

A: We've all seen those charming images of kittens  lapping up a saucer of milk. Yes, it's adorable. But is cow's milk the perfect food for cats? Not at all! 

on the contrary  , some cats (like some people) can't tolerate milk products. For these animals, a saucer of milk means gastric upset.

In the wild, kittens never drink milk after they're weaned, and domestic cats have no reason to either. The  inability to digest milk usually starts around the age of 12 weeks.

On the other hand, if your cat likes and can tolerate milk, feel free to offer it as an occasional treat. Milk is a good source of nutrients for those cats who don't find it upsets their  tummy. But if you never give milk to your cat, she's not missing anything important.

Q: Do cats purr only when they're happy?

A: Expert cat observes 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 needs a friend, is happy or is in pain . It seems to be a sound that both conveys and creates comfort.

Here are a couple more interesting facts about purring: While all the smaller members of the cat family 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.

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.

Cats purr at a frequency of 25 vibrations per second.

Vocabulary Focus

wean (v) ---to start to give a young animal solid food, instead of its mother's milk

digest (v) ---to change food in the stomach into substances the body can use

convey (v) ---to express a thought, feeling or idea so that it is understood by others

vibration (n) ---the process of shaking with small, quick movements

Specialized Terms

gastric (adj) --- 胃的 relating to the stomach