Media hype misrepresents dog flu threat


Despite some media reports to the contrary, dog flu isn’t sweeping the nation.

It’s flu season, sure, but reports of nationwide infections in dogs have been misinterpreted.

Canine influenza virus (CIV) is a highly contagious viral infection that not only affects dogs, but cats as well. At present, two strains have been identified in the United States: H3N8 and H3N2.

Canine H3N8 was first identified in racing greyhounds in Florida in 2004 and is thought to have mutated from an equine influenza strain that jumped from horses to dogs. Canine H3N8 has since been identified in dogs in most US states and the District of Columbia.

Canine H3N2 was first identified in the United Sates in 2015 after an outbreak of canine respiratory illness in the Chicago area. Previously, it had been isolated to South Korea, China, and Thailand, where it was believed to have originated as an avian influenza that jumped from birds to dogs.

Neither strain has been shown to infect humans.

Tracing reports of the “outbreak” are instructive. Earlier this month, the San Francisco Chronicle reported an outbreak of canine influenza in the Bay Area. A few days earlier, FOX news reported that cases of dog flu had “spread to at least 46 states.” That “46 states” figure pops up over and over in other stories from media outlets around the country and appears to trace back to a website called, administered by Merck Animal Health.

That site states that “as of January 2018, Dog Flu has been confirmed in 46 states.” Which may sound like an epidemic on the face of it. But if you break it down, what the site is saying, quite accurately, is that cases of dog flu have been confirmed in 46 states since 2007.

Which is a far cry from saying that there are active cases of canine influenza in 46 states today, which is how many media outlets seem to be reporting the story.

The figures on the site are accurate, but it sure looks likes the media is misinterpreting the data and running with it: the idea of a nationwide outbreak makes for great headlines.

NEWStat reached out to Amy Glaser, director of the Molecular Diagnostic Laboratory at Cornell’s Animal Health Diagnostic Center, which first identified H3N8 in greyhounds in Florida in 2004, for clarification. Glaser confirmed that people are misinterpreting the figures on the website. “It is true that CIV has been identified in samples from dogs in 46 states, but 46 states are certainly not currently experiencing flu transmission in dogs,” Glaser said.

So where are all the sick dogs?

“Canine flu is currently active in only two geographic regions that we know of,” Glaser said. That would be northern Kentucky/southern Ohio and central California. And if you click on that link and look at the map, all those gray dots might look intimidating, but Glaser says it’s the colored ones that count. “The grey dots represent samples from dogs that were flu negative.” Glaser said those dogs were sick but turned out to have “something else” besides canine influenza. “There is no national epidemic that I know of,” Glaser said.

Photo credit: © iStock/jane

NEWStat Interesting/unusual