The flu isn’t a problem just for humans, pigs, horses and birds—dogs can get it, too…and they can die from it. If you’re surprised by this news, you’re not alone.

As early as 1999, researchers began catching on to an illness that was striking greyhounds at racetracks across the country. The dogs would rapidly develop a cough, nasal discharge and fever—and some died from respiratory complications, mainly pneumonia. When the virus was analyzed, it was discovered that the dogs were infected with a variation of the equine influenza (H3N8) virus, the flu virus that infects horses. The virus had mutated to the point that it could not only infect dogs of all types, but it could also be transmitted from dog to dog—and could legitimately be called a canine influenza virus, or CIV.

I recently called Cynda Crawford, DVM, PhD, clinical assistant professor of shelter medicine at the College of Veterinary Medicine at the University of Florida in Gainesville and one of the first researchers to study CIV. Dr. Crawford estimates that thousands of dogs have been infected, though exact numbers are unknown. Unlike the human flu, which affects most people during winter, CIV strikes evenly throughout the year. In about 1% to 5% of cases, the dogs die, according to Dr. Crawford’s personal experience, but she said that most do recover without any complications.

That’s good, but what about the future, since flu germs can sometimes mutate and spread like wildfire?

WHERE DOG FLU HITS THE HARDEST

CIV has obviously not reached epidemic proportions (or we would have heard more about it). But that doesn’t mean that it won’t in the future. “Flu viruses are unpredictable and sporadic in terms of where and when they strike,” Dr. Crawford said. Similar to flu in people or horses, the viruses can arise suddenly and then spread rapidly—exponentially—through a population. Who should be most concerned about CIV?

  • Dr. Crawford said that, at the moment, the virus seems to be most active in the mid-Atlantic states (from New York south through Maryland), California, Colorado and Texas. Dog owners who live in those states should be especially alert for news about confirmed cases in their communities.
  • Owners (in any state) who regularly put their dogs in places where they’ll interact with lots of other dogs should also be on guard. For example, compared with dogs who hang out mainly inside the home or in the yard, these dogs are at higher risk—dogs that often go to kennels, show dogs that perform in competitions, working dogs (such as police dogs and those that help the blind) and even dogs that interact with other dogs in parks.
  • Owners (in any state) who hear about a local outbreak through a news outlet or a neighbor should be extra alert.

HOW IT SPREADS

CIV spreads much like flu in people—through touching contaminated surfaces, sneezes, coughs or direct contact with an infected dog (such as dogs licking each other’s faces or drinking from an infected dog’s bowl). A person can’t be infected by the virus, but a person who doesn’t wash his hands after touching an infected dog could spread the virus to a healthy dog.

Dogs of any age are susceptible. Infection is generally characterized by fever, cough, sneezing and discharge from the nose and sometimes the eyes—but the cough is the main sign. It can persist for one to two weeks and sometimes even longer, and in some cases, it can lead to pneumonia—and the pneumonia is what can lead to serious complications and death.

If your dog experiences CIV symptoms, call your vet immediately (the vet will need time to prepare for your dog’s visit so that other dogs in the waiting room are not exposed.) Then the vet can test for the virus through a nasal swab or blood test. There’s no specific medication to clear it up, but letting the dog rest and not encouraging exercise (such as by throwing a Frisbee) will help your pet fight off the virus.

If your dog has CIV, look out for signs of pneumonia (worsening cough, no appetite, lethargy, increased effort to breathe and a body temperature of 103°F degrees or higher—stick a digital thermometer into the rectum). If you notice any of these symptoms, call your vet for further instructions.

TO PROTECT YOUR PUP

One interesting development is that two years ago, Merck Animal Health introduced a vaccine for the dog flu. This product, Nobivac canine influenza H3N8, is effective at limiting the severity and duration of the infection, lowering the risk for pneumonia, and making your dog less contagious to other dogs. But it will not make a dog less likely to get the flu. Pfizer Animal Health recently introduced its own version of the vaccine, Vanguard CIV. Again, this doesn’t prevent infection.

Whether or not you decide to get your dog vaccinated, stay in touch with other dog owners in your area and alert each other if any cases of dog flu appear.

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