Could your dog unleash a flu pandemic?

Dog lovers might be distressed by the latest research on flu pandemics.

 That all spells trouble for humans, because they spend so much time at close quarters with their canine friends, the researchers noted.

Why dogs? 

"The majority of pandemics have been associated with pigs as an intermediate host between avian [bird] viruses and human hosts. In this study, we identified influenza viruses jumping from pigs to dogs," said study author Adolfo Garcia-Sastre. He's director of the Global Health and Emerging Pathogens Institute at the Icahn School of Medicine at Mount Sinai in New York City.

15 years ago, researchers found that a flu virus in a horse infected a dog, leading to the first circulating flu viruses in dogs. Five years ago, researchers identified a bird-origin flu virus circulating in farm dogs in China.

"In our study, what we have found is another set of viruses that come from swine that are originally avian in origin, and now they are jumping into dogs and have been reassorted with other viruses in dogs," said Garcia-Sastre.

"We now have H1N1, H3N2 and H3N8 in dogs. They are starting to interact with each other. This is very reminiscent of what happened in swine 10 years before the H1N1 pandemic," Garcia-Sastre said.

The findings, published in the journal mBio, show the need to take steps to limit the circulation of flu viruses in dogs, according to the researchers.

One more host

"The United States is free of avian influenza because every time avian influenza has been detected in poultry in this country, the chickens or turkeys are culled and eliminated from circulation," Garcia-Sastre explained in a journal news release. "There are attempts to restrict influenza virus in pigs through vaccination and one could consider vaccination for dogs."

Future studies will assess whether humans are immune to canine H1N1 or not, the researchers said.

"If there is a lot of immunity against these viruses, they will represent less of a risk, but we now have one more host in which influenza virus is starting to have diverse… characteristics, creating diversity in a host which is in very close contact to humans," said Garcia-Sastre.

"The diversity in dogs has increased so much now that the type of combinations of viruses that can be created in dogs represent potential risk for a virus to jump to a dog to a human," he said

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