Canine Influenza - H3N8; H3N2
Key Points about Canine Influenza
- Dog flu is a disease of dogs. No human infections with canine influenza have ever been reported.
- There are two different influenza A dog flu viruses: an H3N8 virus and an H3N2 virus.
- Canine influenza H3N8 virus has been known to exist for more than 40 years.
- H3N8 originated in horses.
- H3N8 first recognized in dogs in 2004.
- Canine influenza H3N2 is an avian flu virus that adapted to infect dogs.
- Canine H3N2 is different from human seasonal H3N2 viruses.
- Canine H3N2 virus first detected in dogs in South Korea.
- Detected in U.S. in April 2015.
- It is not known how canine H3N2 virus was introduced into the United States.
- The signs of this illness in dogs are cough, runny nose, and fever; but not all dogs will show signs of illness.
- The severity of illness dogs can range from no signs to severe illness resulting in pneumonia.
- Most dogs recover in two to three weeks.
- The percentage that dies is less than 10 percent.
- Nearly all dogs are susceptible to infection.
- Dogs frequently or regularly exposed to other dogs – for example, at boarding or day care facilities, dog parks, grooming salons, or social events with other dogs present – are at greater risk of coming into contact with the virus.
- Canine flu can spread to other dogs by:
- direct contact with aerosolized respiratory secretions (coughing and sneezing) from infected dogs.
- uninfected dogs coming into contact with contaminated objects.
- moving contaminated objects or materials between infected and uninfected dogs.
- Dog owners whose dogs are coughing or showing other signs of respiratory disease should not expose their dog to other dogs, and should contact their veterinarian.
- A vaccine to protect dogs from influenza A H3N8 has been available in the US since 2009.
- It is not known if this vaccine will offer protection against the H3N2 dog flu virus seen recently.
For more information, visit www.cdc.gov/flu/news/canine-influenza-update.htm or