Dog flu, also know as canine influenza (CIV), is a very contagious viral disease that first appeared in Florida at a greyhound racetrack in 2004. This respiratory disease spread very rapidly. Researchers at University of Florida worked with Cornell University virologists to identify this new disease. This flu virus, called H3N8, is related to equine influenza and has now spread to 45 states. There is a vaccine that is very safe and effective that contained the disease.
In 2015 there was another severe outbreak of respiratory disease. This time in the Chicago area and over 1,000 dogs were affected. This virus was typed as H3N2 canine influenza virus. This new CIV infection is of avian origin and closely related to the South Korean virus. It has now spread to 31 states. In July of this year there were positive flu cases in New York City (36), Michigan (77), Connecticut (12) and Pennsylvania(2). There have also been positive cases in Massachusetts and New Jersey. As you can see it is headed this way.
Canine Influenza is a highly contagious respiratory virus that causes fever, lethargy, loss of appetite, nasal discharge and cough. The cough and runny nose can mimic the typical signs of “kennel cough”. The veterinarian may suspect the new CIV when a coughing patient has a high fever, severe depression, and anorexia. In this case bloodwork and radiographs are the next step to look for pneumonia and swabs are taken to send to Cornell for cultures and viral isolation.
The new flu, H3N2 has a longer contagious period up to 24 days, making it more of a concern. The virus spreads rapidly from dog to dog via the cough and nasal discharge fluids. Contaminated objects such as toys, dog bowls, clothing, will harbor the virus for days. This is especially a problem at boarding facilities, groomers, dog parks and any area where dogs co-mingle. Some dogs only show mild clinical signs and will carry the virus that quickly spreads to uninfected dogs.
Treatment consists of supportive care while the viral infection runs it course. Antibiotics are often prescribed to prevent secondary bacterial infections. Coughing dogs should stay at home for the protection of other dogs and to rest. A visit to the veterinarian is a good idea to get advice on treatment and diagnostics. The staff may want to keep the dog isolated and avoid contact with other dogs in the waiting room. At our hospital we ask the client to wait with the dog in the car until a technician can escort the dog and owner into a separate isolation exam room with its own exterior door.
Canine influenza is best prevented by vaccination. A safe and effective CIV vaccine that prevents against both strains (H3N8 and H3N2) is now available. If you board your dog at a kennel or daycare, be sure that the facility is well managed and clean and has a plan for isolating dogs with signs of respiratory disease. A boarding facility that requires vaccinations for contagious disease is an extra measure of prevention.
Dogs, with social lives that are already protected with the original CIV vaccine, should be vaccinated with the new H3N2 vaccine. Although both strains of CIV are H3 viruses and share some traits in common, the antigens of H3N2 are different from the H3N8 virus strain, so the vaccine from one strain may not provide protection against the other strain.