The Washington PostDemocracy Dies in Darkness

Why are there so many dead pigs in China’s rivers?

Dead pigs wrapped in plastic sheets on the banks of the Gan river in China’s Jiangxi province on March 18. (AFP/Getty Images)

Another 170 were found last week, bobbing in a Yellow River tributary in northwestern Qinghai Province. No one knew where they had come from or when they had arrived. Locals just knew that these pigs were dead.

“The source of the dead pigs is still under investigation,” China’s state media reported Wednesday.

It was a similar story last month, when 157 dead pigs were fished out of a Yangtze River tributary. Officials said they had no idea what was causing the pig deaths.

And it was a similar story last year, when 6,000 dead pigs were pulled from Shanghai’s waterways in three days. Over the next 10 days, 10,000 more were foundImages showed Chinese workers clustered around trucks brimming with dead pigs.

Cities pulsed with gossip. People fretted over food safety. Was the water safe to drink? What had killed the pigs?

Answers — then as now — have been scarce.

The government has done everything it can to stamp out conspiracy theories involving the deluge of dead pigs. It censored China’s vociferous microblogs, which suggested the public should organize peaceful protests. Bloggers perceived something bigger — and perhaps darker — going on with the dead pigs.

“[Officials] are only giving the runaround,” said Shanghai microblogger Huang Beibei, who photographed the deceased swine in grisly detail. “Who believes what they are saying?”

Locals authorities had their own theories. There did not appear to be any pig disease or epidemic. But it had gotten colder. Perhaps the pigs had frozen to death en masse and fallen into rivers?

Others theorized a police crackdown on the pork black market forced traders to kill and dispose of their pigs. Yet another hypothesis held that farmers are feeding their pigs bits of arsenic to make their skin shine — and have perhaps gone a bit overboard. One joke, according to the Post’s William Wan, is that pigs are killing themselves after refusing to breathe China’s polluted air.

The government, the Associated Press reported, has not commented on any of the theories.

But dead pigs isn’t just a Chinese problem. It’s happening in America as well. A virus never before seen in the United States has killed millions of baby pigs in less than a year. With little known about how it spreads or how to stop it, it’s threatening pork production and pushing up prices by 10 percent or more, the AP reports.

Scientists think porcine epidemic diarrhea, which does not infect humans or other animals, came from China, but they don’t know how it got into the country or spread to 27 states since last May. The federal government is looking into how such viruses might spread, while the pork industry, wary of future outbreaks, has committed $1.7 million to research the disease.