Dog flu prevention is easy, but it will take a trip to the vet.

By Lauren Phillips
Updated July 06, 2018

You may get a flu shot every year—but does your dog?

If your dog hasn’t been vaccinated against dog flu (formally known as canine influenza), it may be time to schedule a trip to the vet.

The dog flu is a contagious respiratory disease, like the common flu in humans. No human has ever caught dog flu, according to the CDC—like how dogs are unlikely to catch the human flu—but the virus is easily spread among dogs. Dog flu can spread especially quickly in spring and summer, when many dogs and people are outside more. Dogs can catch it through direct contact with an infected dog, through an infected dog’s coughs or sneezes, or by playing with a contaminated object an infected dog came into contact with. The illness can spread dangerously quickly in close-quarters situations such as at doggie day cares, in enclosed dog parks, or at grooming centers. (Pets housed in animal shelters are especially vulnerable.)

The virus can even spread by being carried on human clothing, so you could potentially bring the disease home by petting an infected dog on the street and then heading home to your own pup; the virus (again, harmless to humans) can live on hands and clothing for several hours. If you hire a dog sitter or walker who cares for several different dogs in different homes throughout the day, this could easily affect your dog.

Common dog flu symptoms include a low-grade fever (around 103 degrees Fahrenheit), a runny nose, a lack of energy or sleepiness, a cough, eye discharge, and loss of appetite. Not all dogs show signs of the illness, though, so a dog that appears to be healthy could easily spread the virus to other dogs. Most dogs recover within 2 to 3 weeks, but the severity of the illness can vary and lead to pneumonia or even death (for a very small percentage of dogs) in some instances.

A strain of dog flu is currently spreading rapidly across areas of New York City, with reports of canine influenza in Brooklyn and Manhattan. This strain is believed to have come to the United States in 2015, when a Chicago outbreak sickened thousands of dogs across the city; by April 2018, all but four states in the United States have seen at least one strain of the illness.

Fortunately, prevention is easy. There are two strains of the dog flu virus, one of which can affect cats, who can display similar symptoms to dogs. A simple vaccination—like the one offered by Merck Animal Health—can help stop the spread of the dog flu and protect your dog.

“Pups that travel with their families, are social, or visit places like dog parks, doggie daycare, grooming facilities, and boarding kennels are at increased risk for dog flu,” said Dr. Courtney Campbell, veterinarian at VetSurg in Ventura, California, and co-host of Nat Geo Wild’s Pet Talk. “Luckily, dogs can be vaccinated against both strains with a single vaccine. Dogs with a social lifestyle should be vaccinated on an annual basis to prevent illness or decrease the severity of symptoms if they do become sick.”

Instagram-famous pooch Manny (@manny_the_frenchie) visited the Real Simple offices as part of a partnership with Merck Animal Health to help spread the word and promote early vaccination, especially for dogs living in densely populated areas. To learn more about this vaccine (and find a local vet who can vaccinate your dog), visit

To keep your pet safe, talk to your vet about whether your dog is at risk, and whether the vaccine is right for you. Suburban dogs or dogs who don’t frequently come into contact with other dogs may be fine, but if your dog goes to a day care, frequents a groomer or park, or even is walked by a professional walker during the day, you may want to consider a vaccine (with your vet’s approval, of course).

And, of course, if your dog is elderly, a puppy, or has a sensitive immune system, take extra precautions. Should your dog fall ill, schedule a trip to the vet, put your four-legged friend on bed rest, and make sure he or she is drinking plenty of fluids. To prevent him or her spreading the illness, stay away from other dogs for at least three weeks.