Are pigs dying of swine flu, too?

Answers to your questions about the news.
April 27 2009 5:56 PM

Are Pigs Dying of Swine Flu, Too?

No, it's just another day in the sty.

Click here to read more from Slate on the swine flu. 

Depressed pig. Click image to expand.
A veterinarian vaccinates a pig

Swine influenza has killed 149 people in Mexico so far and infected many more worldwide. So how many pigs have died in the outbreak?

No more than usual. The mutation that permitted swine influenza to jump from pigs to people has nothing to do with the virulence or incidence of the disease among swine. So far, there have been no reports of an uptick in pig mortality.

If anything, pigs are safer than people. The mortality rate for swine influenza among swine is somewhere between 1 percent and 3 percent, far lower than the 9 percent mortality rate among people that has been reported in Mexico. When flu viruses jump in the other direction—from human to pig—they've tended to be more deadly for the animals. Many researchers believe humans transmitted the infamous 1918 influenza strain to pigs, causing a deadly epidemic among swine in the 1930s.

Just like people, pigs contract the flu via the transfer of bodily fluids—mostly from the sneezes or coughs of other pigs. They begin to exhibit symptoms within 24 hours, including fever, coughing, discharge from the eyes and nose, and sneezing. Some swine will refuse to eat or show signs of pig depression, such as lethargy, hanging their heads, or declining to socialize with other swine. (Once a pig has been diagnosed with the flu, it's placed in isolation.) Most pigs recover from the swine flu in five to seven days with rest and proper hydration.

Got a question about today's news? Ask the Explainer.

AP video: Obama addresses the swine flu outbreak.

Brian Palmer is Slate's chief explainer. He also writes How and Why and Ecologic for the Washington Post. Email him at Follow him on Twitter.



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