A new strain of canine influenza virus has been in the news a lot lately. The virus has infected dogs in the Midwest and appears to have originated in Asia. The strain, called H3N2, was originally isolated nearly ten years ago but has never before been implicated outside of South China and South Korea. It is uncertain how it made its way to Chicago a few weeks ago where it has infected more than 1,000 dogs and has been blamed on 5 deaths. Doctors at both Cornell and Wisconsin Universities are working feverishly to simplify the diagnosis and treatment of this disease. At this time the virus appears to be confined to Illinois, Wisconsin, Indiana, and Ohio.
There is another strain of Canine Influenza that was responsible for a large outbreak in 2004, the H3N8 virus. That outbreak, which began at a Grey Hound race track, was responsible for thousands of cases and hundreds of deaths and was originally implicated in this latest outbreak. There is a vaccine for the H3N8 strain but it is unclear whether or not the vaccine will offer any cross protection against the new H3N2 virus. At this time there is not a vaccine for the H3N2 Asian flu.
Symptoms of canine flu vary from mild to severe and are very similar to the symptoms we humans experience with the flu. Lack of appetite, cough, runny nose, malaise and fever are common, and mild cases can last anywhere form 10-30 days. Severe cases, on the other hand can cause a terrible pneumonia and are associated with fevers in excess of 104 degrees Fahrenheit. It can even evolve into a hemorrhagic form which causes the affected dog to cough up blood. If symptoms persist for more than 2 or 3 days, your dog should be hospitalized for supportive care. Dogs with symptoms should immediately be kept away from other dogs for a minimum of 2 weeks. Definitive diagnosis is tricky and often cost prohibitive. Currently there are no specific tests available for your veterinarian to diagnose this new strain and tests for the H3N8 strain will not work. Scientists are working to develop a commercially available test though. The best advice for now is to quarantine dogs with the above symptoms for a minimum of 2 weeks. This quarantine can be done at home. Pet owners are encouraged to keep their dogs out of dog parks, pet stores, and anywhere else where nose to nose contact is commonplace.
In summary, this new strain of Canine Flu appears to be confined to the Midwest. There is not, at this time, a commercially available test for your veterinarian to diagnose this new strain, and there is not a vaccine yet. With that said, the veterinary community is watching this outbreak closely and as long as pet owners are aware of the symptoms and what to do should they see any of them, most dogs should do fine with supportive care either at home or in a hospital.