WEDNESDAY, June 14, 2017 (HealthDay News) -- A highly contagious flu that infects dogs and can be fatal is spreading throughout the United States.
"New viruses emerge in animals periodically, and this is an example of a virus that got transmitted from birds to dogs," said Colin Parrish, a professor of virology at Cornell University's College of Veterinary Medicine in Ithaca, N.Y. "It's a new canine virus."
This is an H3N2 flu virus that emerged in Asia in 2005 and spread to the United States, probably in dogs brought over from Korea in 2015, Parrish added.
About 80 percent of the dogs that come into contact with this virus catch the flu, according to Dr. Joe Kinnarney, the immediate past president of the American Veterinary Medical Association.
Parrish said it was first seen in Chicago and spread to other areas in the Midwest. Recent outbreaks have occurred in Florida, Georgia, North Carolina, South Carolina and Texas. This particular strain of flu seems to be more contagious than an earlier dog flu seen in 2004, Parrish said.
"We did have a second introduction of this virus into Los Angeles back in March from dogs brought out of Asia not properly quarantined, and an outbreak occurred there with a different lineage of the virus," said Edward Dubovi, a professor of virology at Cornell's College of Veterinary Medicine.
"If these groups that want to rescue dogs from Asia continue to irresponsibly bring them into the United States, then this flu is going to be reintroduced now and then as they bring in infected dogs," Dubovi said.
The good news is "there's no evidence that this flu infects humans," Parrish said.
But much like human flu, which spreads where people congregate, dog flu spreads when dogs gather, Parrish said. That can include shelters, doggy day care places, kennels, dog shows and dog parks.
People can also transmit this flu to dogs, Kinnarney noted. "I can be touching a dog that has the virus and then go to touch another dog, and I can give that dog the virus," he explained.
Symptoms of the dog flu are just like human flu, Parrish said. Dogs often cough, run a fever and look sick. "If you look at a human and a dog that's had flu, it would be pretty similar," he said.
If your dog comes down with the flu, you should take it to a vet, Dubovi said.
"Like people, we don't have a cure for a virus, so it's giving the dog supportive care," Kinnarney said.
That includes keeping dogs well-hydrated and making sure they eat, he said. "If there is a fever, we will give something to help with the fever. I may put them on IV fluids, and if there are bacterial infections we may add an antibiotic," he added.
"In North Carolina I know of two deaths from dog flu," Kinnarney said.
There is a vaccine that works pretty well, Parrish said. "As far as we know, it's about 60 to 80 percent effective, and if a dog gets [an] infection, the symptoms are less severe, very much like human flu vaccination," he said.
For the vaccine to be fully effective, two doses, given a couple of weeks apart, are needed, Dubovi said.
If your dog is going to be in contact with other dogs, it's probably a good idea to have it vaccinated. If, however, your dog stays home and doesn't congregate with other dogs, a vaccination might not be necessary, Parrish said.
"The dog world is grappling with it," Dubovi said. "Some kennels and doggy day care centers are requiring dogs be vaccinated. The current outbreak rolling through the Southeast seems to have originated at a dog show or two."
The vaccine is very safe, so the main reason for not vaccinating your pet is the cost, Parrish said.
Dubovi advises dog owners to assess for themselves what risk their dog has for contracting this virus.
"If you go to dog shows, if you go to day care, if you board your dog a lot or if you go into dog parks you really should vaccinate," Kinnarney said.
Like human flu, some dogs die from flu. The dogs most at risk are very old or very young or have another medical condition, he said.
What can make this flu serious is if the dog develops a bacterial pneumonia, Dubovi said. Some breeds, such as bulldogs and German shepherds, may be more susceptible to serious lung infection, he said.
Parrish said the flu usually lasts for about a week, but dogs can have a cough that lasts for another week.
This strain of flu can also infect cats, Parrish said. "There have been cases reported in cats, so occasionally cats will get infected," he said.
More information
For more on dog flu, visit the U.S. Centers for Disease Control and Prevention.