Jasper is an Asiatic black bear, also known as a moon bear because of the yellow crescent on his chest. In 2000 he came to the Animals Asia Moon Bear Rescue Centre in Chengdu, China, from a bear farm.

When Jasper arrived his rescuers had to cut him out of a tiny "crush cage" that pinned him down so the farmer could extract lucrative bile from his gall bladder. Bear bile is used in traditional Chinese medicine and fetches a tidy price. In China, the wholesale price is around 4000 yuan (approximately $580) per kilogram; each bear produces up to 5 kilograms a year. But it comes at terrible cost.

Jasper spent 15 years in his cage. Other bears spend up to 25 years in cages no bigger than their bodies, barely able to move. Bears are milked for bile twice a day. In China, farmers use a crude catheter inserted into the gall bladder or a permanently open wound. In Vietnam, they use long hypodermic needles.

Over the past 10 years, Animals Asia has rescued 260 bears from Chinese bear farms. These are the lucky ones. The official number of farmed bears in China is 7000, but Animals Asia fears the real figure is closer to 10,000.

Despite its obvious cruelty, bear farming is legal in China. While CITES, the Convention on International Trade in Endangered Species, lists Asiatic black bears at the highest level of endangerment, China grants them only second-level protection, which allows them to be farmed. There are no reliable estimates of the remaining wild population in China, though some have put it as low as 15,000.

Bear farming is also practised in Vietnam, where it is illegal but remains widespread because of a lack of enforcement. There are around 4000 bears on Vietnamese farms and yet more in Laos, Cambodia and Korea.

In China, bear farming is justified on the grounds that it satisfies local demand for bile, hence reducing the number of bears taken from the wild. Farms are allowed to breed bears in captivity and hunting wild bears has been illegal since 1989. Despite this, many wild bears are still poached for their whole gall bladders or to restock the farms. Bears sometimes arrive at the rescue centre with missing limbs after being trapped in the wild.

The rescue programme was sparked in 1993 when Animals Asia founder Jill Robinson visited a bear farm. After years of government lobbying the rescue centre was set up in 2000 and now houses up to 175 bears.

Broken bodies

Those bears who reach the centre have invariably suffered serious physical and psychological trauma. Rescued bears can't be released into the wild because of the long-term damage caused by their incarceration. All need surgery to remove damaged gall bladders and many need additional surgery and long-term medical care due to missing claws or paws, infected and necrotic wounds and broken and missing teeth caused by biting at bars or because farmers break them to make the bears less dangerous. Many also have liver cancer as a result of being continually milked for bile, plus a litany of other ailments including blindness, arthritis, peritonitis, weeping ulcers and ingrown claws.

In contrast to the horrors of bear farming, the rehabilitation process is amazing and inspiring to witness. It takes around a year to rehabilitate a bear. Although a handful have to be kept alone for the rest of their lives, most can eventually be housed with other bears. The transition in personality from animals who are violent and fearful to ones who are trusting, inquisitive and completely at ease with people is truly remarkable, Robinson says. She is right. I have visited the rescue centre and it changed my life. That is how powerful the bears' stories are.

Watching rehabilitated bears play is a joy. Many continually seek out playmates, an indication that they have substantially recovered from their trauma. I once saw two bears called Aussie and Frank frolicking on a hammock. When Aussie saw Jasper ambling over, he jumped off the hammock, approached Jasper, and they began play-fighting. The deep trauma they had experienced wasn't stopping them from enjoying themselves. Yet some bears have behavioural scars and flashbacks from their unspeakable abuse. Aussie still scampers back to his den when he hears a strange noise.

Despite the rescue programme bear bile extraction remains a cause of wanton and remorseless abuse. It is hard to change attitudes when bear bile has been used in Chinese medicine for more than 3000 years to treat "heat related" ailments such as eye and liver diseases. Today it is used to treat conditions from hangovers to haemorrhoids.

There is some evidence from western medicine that a synthetic version of the active ingredient in bear bile, ursodeoxycholic acid, can treat a range of diseases, including hepatitis C. Yet traditional Chinese medicine still insists on using natural bear bile, which is often contaminated with pus, blood, urine and faeces. While healthy bear bile is free-flowing and orangey-green, veterinarians describe bile leaking from the diseased gall bladders of rescued bears as "black sludge".

The moon bear rescue project raises a number of important questions. For example, why do bears show large individual differences in response to persecution, and variations in recovery? Rescued bears are powerful ambassadors, but should so much time and money be invested in saving the lives of individuals who will not make any direct contribution to saving their species? How can people from outside China work to free bears while respecting their Chinese colleagues and remaining sensitive to cultural traditions? It also raises questions about how people can act in undignified and shameful ways that ignore the horrific pain and suffering of highly sentient animals.

Efforts to stop bear farming are ongoing. Soon after Robinson founded Animals Asia in 1998, she negotiated an agreement with the Chinese government to work towards the elimination of bear farming. All farms are inhumane, but the very worst are identified for closure by the government and the farmers have their licences permanently revoked. It is from these farms that bears come to the rescue centre. Animals Asia compensates the farmers so that they can start another business or retire. More than 40 farms have so far been closed, and China has not issued any new licences since 1994.

Animals Asia has also submitted a proposal to the government to help wind down the industry, including offers to help bear farms become rescue facilities.

There is still much to be done to right the wrongs of bear farming. Robinson looks to the day when all farmed bears will wake with the sun on their backs and without fear in their hearts. Each bear surely appreciates the effort. Just look into their eyes. I have.