CHENGDU, China » It was, at first glance, a rather modest initial public offering by a small Chinese company seeking to expand production of the key ingredient used in traditional remedies said to shrink gallstones, reduce fevers and sooth the aftereffects of excessive drinking.

But Guizhentang Pharmaceutical, the country’s largest producer of bear bile extract, apparently overlooked one important factor before submitting its application to the Shenzhen Stock Exchange: China’s increasingly audacious animal rights movement.

Guizhentang’s proposal to triple the company’s stock of captive bears, to 1,200 from 400, provoked a firestorm from those opposed to bear bile farming, a process that involves inserting tubes into the abdomens of bears and "milking" them, sometimes for years.

Protesters in bear suits picketed drugstores, hackers briefly brought down Guizhentang’s website and more than 70 Chinese celebrities, including the basketball legend Yao Ming and the pop diva Han Hong, circulated a petition calling on the stock exchange to reject the IPO.

After some of China’s biggest news media outlets posted harrowing undercover footage revealing cages so tight the bears could barely move, Guizhentang last month withdrew its application, saying it needed more time to put together its filing.

For China’s animal welfare advocates, the victory signaled the growing clout of a movement that is frequently derided as bourgeois, frivolous or worse. Its most vociferous opponents paint animal advocates as foreign-financed traitors who would do away with such hallowed Chinese traditions as dog meat hot pot, ivory carving and dried deer penis.

Deborah Cao, a lawyer who frequently writes about animal rights in China, said campaigns like the one that defeated Guizhentang showed how social media brought together the generation of educated Chinese urbanites who grew up with household pets and anthropomorphic Disney characters. "It’s a bottom-up, grass-roots movement, one that is contributing to an emerging civil society increasingly aware of individual rights and obligations, be it to humans or animals," she said.

Such activism is even more notable given the constraints the Communist Party typically imposes on public lobbying, street protests or any unsanctioned organizing.

Advocates have not yet persuaded the government to enact animal welfare legislation. But optimists say they have started to chip away at the long-held notion that animals exist to satisfy the medicinal and gastronomical needs of humans.

Activists point to the growing visibility of public awareness campaigns targeting the consumption of shark fins as well as a recent spate of vigilante attacks that have blocked trucks laden with cats and dogs from reaching the slaughterhouse. In December, the state-run broadcaster CCTV ran a series of exposis highlighting the illegal consumption of monitor lizards, rhesus monkeys, barking deer and other wildlife, and the police crackdown on black market dealers that followed.

"Animal rights activists are walking an incredibly sensitive tightrope, but I think they’re reaching a tipping point right now," said Jill Robinson, the director of Animals Asia, an organization based in Hong Kong that has been campaigning for two decades to end bear bile farming.

Still, despite what appears to be growing public opposition to the practice, the Chinese government is not prepared to end the lucrative trade in ursodeoxycholic acid, the active ingredient found in bear gallbladders. Although scientists have engineered a synthetic alternative, traditionalists claim it lacks the therapeutic punch of raw bile, which can sell for as much as $24,000 a kilogram, roughly half the price of gold.

Scientists have scrutinized the health effects of bear bile but have come to no definitive conclusions. But sold in powdered form as capsules, or as a tonic, bile is considered by many to be an elixir of sorts. Bile marketers say it fortifies the liver, reduces flu symptoms and improves eyesight.

Yang Tingying, a vendor at the wholesale Chinese medicine market here in Chengdu, the provincial capital of Sichuan, insisted that bear bile cures all manner of liver ailments, including hepatitis. "It’s the best because it’s from nature," she said, pulling out a pair of desiccated gall bladders, which are illegal to sell.

To the distress of its opponents, the industry has grown significantly in the 13 years since Chinese officials first pledged to gradually reduce the number of captive bears to 1,500 from 7,000. These days, there are an estimated 20,000 bears on nearly 100 domestic bear farms, an expansion fueled in part by marketing efforts promoting novel uses for bear bile, such as a hangover cure for well-to-do businessmen who engage in nightly carousing.

Besides China, there are bear bile farms in Vietnam, Laos, Myanmar and North Korea.

For animal welfare advocates, the challenge is to convince Chinese consumers that the barbarity of bile farming outweighs the supposed medicinal benefits of natural bile – or that the risks of consuming bile from sick bears pumped with antibiotics are high.

In addition to circulating videos of harvesting practices, organizations like Animals Asia wield a number of secret weapons, including Sun Li, Caesar and Buddha. They are among the 158 rescued bears that roam the group’s sanctuary near Chengdu. The center receives school groups, celebrities and Chinese reporters, all of who are invariably smitten with the bears.

Most of the animals came from farms closed by the authorities because they had fewer than 50 bears, a violation of industry rules. The bulk of the animals are Asiatic black bears, a threatened species better known as the moon bear.

Nicola Field, the sanctuary’s chief veterinarian, said bears often arrived emaciated, their abdomens riddled with the infections, hernias and tumors that are hallmarks of a extraction process requiring open wounds for thrice-daily milkings.

The bears’ teeth are invariably worn down from gnawing on the bars of their cages and their feet are often in pitiful shape because few of the animals have ever walked on the ground. "The catalog of abuse they’ve endured is appalling," Field said.

The years of pain and confinement are so traumatizing, some of the rescued bears spend endless hours butting their heads against walls or gnawing on their limbs.

Industry supporters have mounted their own pro-bile public relations campaign, stressing China’s history of traditional medicine and suggesting that animal rights advocates are doing the bidding of foreign drug companies out to promote Western medicine at the expense of homegrown remedies.

During a news conference last year called to counter critics, Fang Shuting, chairman of the China Association of Traditional Chinese Medicine, suggested that bears enjoy the process, which he likened to turning on a tap. "Natural, easy and without pain," he said. "After they’re done, the bears can even play happily outside."

His remarks backfired, producing a torrent of ridicule on social media and refutations from experts who said bear farmers could not possibly let the animals leave their cages. "Bears are smart like dogs and remember pain," said Zhang Xiaohai, who has visited a number of bear farms as an undercover investigator for Animals Asia. "They would never willingly come back to be milked again."

But animal rights activists find hope in the attitudes of young Chinese like Guan Zhiling, who was visiting the sanctuary with her high school classmates. "It’s brutal and disrespectful to the bears, and a disgrace to the human race," she said.

© 2013 The New York Times Company