Respiratory Disease Outbreak 2023 – Learn More

Canine Influenza Virus

Canine influenza (CI, or dog flu) is caused by the canine influenza virus (CIV), an influenza A virus. It is highly contagious and easily spread from infected dogs to other dogs by direct contact, nasal secretions (through barking, coughing or sneezing), contaminated objects (kennel surfaces, food and water bowls, collars and leashes), and by people moving between infected and uninfected dogs. Dogs of any breed, age, sex or health status are at risk of infection when exposed to the virus.

The symptoms of a CIV infection resemble those of canine infectious tracheobronchitis (“kennel cough”). Dogs infected with CIV may develop a persistent cough, a thick nasal discharge and fever (often 104-105oF). Other signs can include lethargy, eye discharge and decreased appetite. The majority (80%) of infected dogs develop flu-like illness ranging from mild to severe illness. Some infected dogs may not show any signs of illness, but can still be contagious and able to infect other dogs. Most dogs recover within 2-3 weeks. However, some dogs may develop secondary bacterial infections which may lead to more severe illness and pneumonia. Anyone with concerns about their pet’s health, or whose pet is showing signs of canine influenza, should contact their veterinarian.

Currently, two strains of CIV have been identified in the U.S. The H3N8 and now the H3N2 virus strain.

Vaccines are available for both the H3N8 and H3N2 strains of canine influenza virus. The CIV vaccination is a “lifestyle” vaccination, recommended for dogs at risk of exposure due to their increased exposure to other dogs – such as boarding, attending social events with dogs present, and visiting dog parks. We are happy to provide you with additional information about the vaccines and whether you should consider vaccinating your dog.

Canine influenza can occur year round. So far, there is no evidence that canine influenza infects people.

Written by: Dr. Lauren Strine