It's shocking to think we live in a world where people -- including wealthy and famous celebrities such as Jennifer Lopez -- still kill for fashion. Yet every year, millions of animals are drowned, clubbed to death, crushed in steel-jaw traps and genitally electrocuted, sometimes just for a little piece of fluff on a coat collar.

We can't stop all the suffering that exists, but I believe we can stop this. That's why I recently teamed up withPeople for the Ethical Treatment of Animals during New York's Fashion Week to tell consumers what fur designers and retailers won't: Those cheap price tags on today's fur coats and fur-trimmed garments come at the expense of animals who are literally skinned alive.

Much of the fur now sold in the United States and Canada originates in China, where there is not a single law to protect animals. Undercover investigators who toured Chinese fur farms found raccoon dogs and silver foxes suffering from severe stress, repeatedly slamming their heads and bodies against the crude wire cages enclosing them. Others huddled helplessly in the backs of their cages, paralysed with fear.

These animals have good reason to be afraid. After a brief and joyless existence in barren cages, with no place to hide from the elements, driven mad by confinement, they will be beaten with metal rods or slammed headfirst against the ground, in a crude and cheap attempt to kill them. But these methods often only break the animals' necks or backs, leaving them panting, blinking and completely conscious as the fur is ripped from their bodies.

It's hard to watch, but I ask anyone who wears fur or finds himself or herself tempted by just a "little trim" on a coat, or a sweater with a fur collar, to see the investigators' footage for themselves at www.FurIsDead.com. I don't believe you can watch this video and still think that fur is desirable.

Something else the fur industry won't tell you: Some of the animals killed for their pelts in China are domestic dogs and cats. They are bludgeoned, hanged, bled to death and strangled with wire nooses so that their fur can be turned into trim, toys and trinkets. These animals are no different from our beloved companions.

When PETA-Germany recently visited the animal market in Guangzhou, in southern China, they found animals in cages who still had their collars on, a sign that they, too, had once been companions, stolen to be made into fur coats. Approximately two million dogs and cats are killed for their fur every single year.

The sale of dog and cat fur has been formally banned in a handful of countries, including the United States, but without expensive DNA testing, it's impossible to tell for sure what -- or who -- you are wearing.

The only way to know beyond a doubt that you are not supporting this gruesome industry is to refuse to wear fur. If you've already taken that compassionate step, thank you. Now please take another: Don't buy clothes from designers who work with fur and don't patronize businesses that sell it. Boycott the films, CDs, perfumes and other products of celebrities who wear it. If we all do this together, as a team effort, we can end the use of fur in fashion once and for all.

Heather Mills McCartney, the wife of Paul McCartney, is a member of People for the Ethical Treatment of Animals