Millions of Americans have already gotten their annual flu shots, but they may not know that their furry friends might be in need of flu vaccinations, as well.
Canine influenza, aka dog flu, is a contagious respiratory disease caused by specific Type A influenza viruses, according to the Centers for Disease Control and Prevention (CDC). There are two known doggie flu viruses — the H3N8 and the H3N2.
The H3N8 virus has been around for nearly 40 years and was a horse-only illness until 2004 when it suddenly spread to dogs. But it's the H3N2 virus that has been making the news ever since it found its way to North America last spring.
In fact, more than 1,500 dogs across 26 states have tested positive for the H3N2 virus since March 2015, according to Cornell University. The outbreak is thought to have originated in Chicago when an infected dog from South Korea arrived at O'Hare International Airport, NPR reports. This most recent flu has even caused illness in cats.
Canine flu symptoms include high fever, loss of appetite, coughing, nasal discharge, and lethargy; however, some dogs are considered silent carriers because they show no symptoms.
Is Your Dog at Risk?
"The canine flu is not necessarily seasonal the way we think of human flu," says Grace Anne Mengel, VMD, staff veterinarian at Penn Vet's Ryan Hospital. "That said, the factors to consider when contemplating the canine flu vaccine are lifestyle factors."
Dogs who spend time in kennels, shelters, doggie daycares, and dog parks "may be at higher risk for infectious respiratory diseases, such as canine influenza," says Dr. Mengel. "Respiratory disease can be spread by aerosol transmission, so any close contact with other dogs — especially in an indoor environment — can raise the risk of disease transmission."
But even if your dog does fit that description, there's no need to panic or rush to get a vaccination. "Contact your vet and ask for advice," recommends Cindy Otto, DVM, PhD, director of the Penn Vet Working Dog Center at the University of Pennsylvania School of Veterinary Medicine. "If there is an outbreak in your area, your vet is going to know first. And if your area is at higher risk, then that's the time to start thinking about it."
'Can I Catch the Dog Flu?' and Other Questions
There are a few more things to keep in mind when considering getting the flu vaccine for your pet, including how effective and long-lasting it may (or may not) be.
"The original influenza that was reported in dogs that was potentially caught from horses — that's what the vaccine is directed at," says Dr. Otto. "The big outbreak we've had recently is a different form of the flu and there's concern that this vaccine may not be protective. But no vaccine is 100 percent protective, and flu vaccines, in particular, are really tough because the flu is willing to change."
Another challenge regarding the dog flu shot: Medical experts have yet to determine how long the immunization period lasts. "The vaccine was approved for once a year, but is it as effective at the end of the year as it is in the beginning? We just don't know."
And yes, there can be side effects, says Mengel. "The most common ones are the same as with most vaccines, which include soreness at the site of injection and lethargy for 24 to 48 hours after vaccination," she says. "More serious reactions are rare, but include vomiting, facial swelling, hives, and difficulty breathing."
While it's likely to spread among dogs, there have been zero reports of humans being infected with either of the viruses. So if your four-legged companion does get the flu, can he still snuggle up in your bed?
"While we don't have any evidence that it jumps species, we also know that the flu can potentially do crazy things," says Otto. "So if your dog is sick, I'd advise letting them sleep in their own bed. It's better for you and better for them."
Ultimately, it sounds like the age-old home remedy for the flu still applies: lots of fluids, rest... and belly rubs.