Photograph by Justin Sullivan, Getty Images
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Veternariary technician Justin Jones (left) tries to distract a dog as he preapares to give a canine influenza immunization at Los Gatos Dog and Cat Hospital on January 25, 2018, in Los Gatos, California.

Photograph by Justin Sullivan, Getty Images
Explainer

No, Killer Dog Flu Isn't the Next Human Pandemic

A study about a new strain of canine influenza made waves this week. Here's why claims about it triggering a human pandemic should give you pause.

Rumors are spreading that the next flu pandemic may come from humanity’s best friends: dogs.

On Tuesday, researchers reported that they identified a new strain of dog flu, called H1N1, in dogs from southern China. If H1N1 rings a sickly green bell, that might be because a pandemic of swine flu went by the same name in 2009. The U.S. Centers for Disease Control and Prevention estimates that the 2009 swine flu affected over 60 million people in the U.S. and killed more than 12,000.

So if Snoopy has the sniffles, do you need to lock him in quarantine? Here’s everything you need to know about dog flu.

Canine Influenza: What You Need to Know

Humanity's best friend is at risk of catching canine influenza year-round. Do you know if your beloved pooch is at risk and in need of a vaccine?

What is dog flu?

Canine influenza virus (CIV) is the strain of the flu that infects dogs, and it’s a pretty recent phenomenon. Unlike human cases of the flu, which have been described for thousands of years, dog flu first appeared less than 20 years ago.

In 2004, a greyhound at a Texas racetrack tested positive for H3N8, a strain of influenza that until then had only been seen in horses. The track was also used for dog racing, so it seems that the virus infected a horse, mutated, and then had a chance to jump across species. Another outbreak of dog flu, H3N2, appeared in Chicago in 2015 after the virus jumped from birds to dogs. That strain is currently spreading among dogs in New York City.

A flu-ridden dog may have a runny nose, lose his appetite, become lethargic, and run a fever; basically, the same symptoms that a person has when they catch the flu.

Will I catch the flu from my dog?

It’s never happened before, and despite the results of the new study, it’s very unlikely to happen anytime soon. The particles on the surface of the virus are like keys that match the distinctive “locks” on an animal’s cells. Canine influenza virus has the key to infecting dogs, and since the virus only causes an infection once it’s inside a cell, it would take a significant mutation to the key for it to infect you. (For instance, a "zombie virus" that's a hybrid of rabies and the flu is improbable, but not impossible.)

Just ask the CDC: In 2016, they used their Influenza Risk Assessment Tool to assess dog flu by characteristics such as preferred host, susceptibility to antiviral drugs, disease severity, and likelihood of human-to-human transmission. They found only a low risk of potential pandemic.

But what about the new study? Doesn’t it say “pandemic?”

The study published earlier this week identified a new strain of dog flu that is related to the 2009 swine flu, which is now called pandemic H1N1.

Like a human has 23 chromosome pairs, a flu virus has eight gene fragments. The viruses can mix and match their genes with other strains, creating new varieties that might jump from pigs to people, as happened in 2009. This crossover happens fairly frequently because the locks on human cells are similar to the locks on pig cells. The jump from pigs to canines was unexpected, though, because their locks are more dissimilar.

But only three of the new dog flu’s genetic fragments came from the 2009 strain of H1N1, and the study authors note that certain factors in that region of China, including widespread feral dogs and dog meat markets, make canine-to-human transmission of the flu more likely. (Here's how we know the 1918 flu pandemic originated in China.)

The study is also not an urgent call to action. Veterinarians collected the samples that contained H1N1 between 2013 and 2015, and so far, the dog flu has only jumped from dogs to cats. Still, the authors recommend further surveillance of the disease.

According to their website, the CDC already conducts year-round surveillance of influenza in animals, and the health agency and the U.S. Department of Agriculture both have protocols in place to respond in “the unlikely event that canine influenza becomes a threat to humans.”

What should I do if I think my dog has the flu?

Vaccines against canine influenza are available, and if Spot has a cough, the first thing you should do is call your vet and see if you should set up an appointment. For the time being, try to keep him away from other dogs who might catch whatever he has. At the vet’s office, there are tests to tell whether your pooch has the flu.

Once a dog is diagnosed with the flu, treatment is straightforward. They’ll need to get lots of rest and stay hydrated for the duration of the disease, which may last up to a month. And since they won’t get you sick, you can give them plenty of cuddles!