NATIONWIDE — Outbreaks of the dog influenza virus increased last summer, and now there are reports of the canine illness, according to a report in Newsweek.

Cases of canine influenza have again been popping up around the country.

“Experts feel dog flu is now endemic in Colorado, Pennsylvania, Florida and now here in California. There’s some controversy over where it originates from; some experts think it came from horse influenza and some think from avian influenza,” Dr. Kyle Frandle, a veterinarian at Los Gatos Dog & Cat Hospital, told Mercury News

This past June, the dog flu was confirmed in more than 30 states, including Georgia, Massachusetts, New Jersey, Alabama, California, Texas, New York, Iowa, Michigan, Wisconsin and Indiana, according to Cornell's Animal Health Diagnostic Center.

Dog flu has yet to be passed to humans or vice versa, but it has a 10 percent mortality rate for canines, experts say.

H3N2 causes a respiratory infection in dogs that looks like “kennel cough.”

Is dog flu the same as human flu?

According to the Center for Disease Control, the H3N2 canine influenza virus is an avian flu virus that adapted to infect dogs. Although H3N2 viruses have been reported to infect cats, dog flu is a disease of dogs. This virus is different from human seasonal H3N2 viruses. Canine influenza A H3N2 virus was first detected in dogs in South Korea in 2007 and has since been reported in China and Thailand. H3N2 canine influenza has reportedly infected some cats as well as dogs. It was first detected in the United States in April 2015. It is not known how canine H3N2 virus was introduced into the United States. 

What are the symptoms? 

Symptoms include sneezing, nasal discharge and frequent coughing that can last for two weeks or more. Some dogs develop more serious disease and pneumonia that requires hospital care.

Most dogs that get canine flu recover, but in the same way the flu affects older humans and those with weakened/new immune systems, young and very old dogs are at a higher risk.

How is it transmitted? 

The disease is transmitted "through droplets or aerosols containing respiratory secretions from coughing, barking and sneezing,” according to the American Veterinary Medical Association. “Dogs in close contact with infected dogs in places such as kennels, groomers, day care facilities and shelters are at increased risk of infection.”

The virus can survive on kennel surfaces, crates, food and water bowls, collars, leashes, toys, beds, vehicles and on clothing and hands for 12 - 24 hours before it dies.

The virus is easily killed by most disinfectants, hand-washing with soap and water, normal laundering of clothing and bedding and washing food bowls, water bowls and toys with soap and water.

What's the best way to prevent? 

Vaccines are available for dogs for H3N2. Two doses of the vaccine must be given for optimum immune response. The doses are administered over a two to three-week period and establish immunity within one to two weeks after the second dose.

And while the vaccine might not completely prevent infection, it will make it less likely. The vaccine is recommended for dogs that frequently board or that are out in social settings.