In the summer of 2015, Atlanta experienced one of the largest outbreaks in the nation of Canine Influenza Virus (H3N2), second only to the initial outbreak in March 2015 in the Chicago area. Since that time, the H3N2 strain has been identified across the United States and continues to emerge in new locations even today.  Between the two strains of canine influenza (originally H3N8 and now H3N2), over 42 states have been affected.  Most recently, CIV H3N2 has also been found in a group of cats in northwestern Indiana, indicating that our feline patients are also susceptible to infection.  

As canine flu continues to pop up across the country, doctors from BluePearl Veterinary Partners are offering guidance for concerned pet parents.


What is canine flu?

Canine flu is a highly contagious respiratory infection caused by the influenza virus. Doctors believe the current epidemic stems from a new strain of the virus that originated in Asia, and it is unknown if the current flu vaccine provides any protection from it. Also, unlike the earlier strain, the virus can cause illness in cats, too.

How is it spread?

The virus is easily spread between dogs, either through direct contact or from aerosol particles via sneezing or coughing. Almost all dogs, regardless of breed or age, are susceptible to the flu.

What are the symptoms?

Signs of infection typically develop within 2-5 days of exposure to the virus and are similar to a bad a bad case of “kennel cough.” Common symptoms include

  • High fever
  • Loss of appetite
  • Coughing
  • Nasal discharge
  • Lethargy


Like treating the flu in humans, there’s no specific medication that can be prescribed. The focus is on providing supportive care, such as proper hydration, and preventing secondary bacterial infections through the use of antibiotics.

Preventing the disease from spreading

Pets diagnosed with canine flu should be isolated from other pets for 10-14 days.

“If your pet begins exhibiting any of the symptoms of canine flu, your first step should be to call your primary care veterinarian,” said Dr. Jennifer Welser, chief medical officer of BluePearl Veterinary Partners.

Is there a vaccine?

Since the Atlanta outbreak, two companies (Merck and Zoetis) have developed vaccines that are now available with conditional licensure for the newer H3N2 influenza strain.  There is no cross-protection between the original H3N8 vaccine and the new H3N2 vaccine, thus for complete canine influenza protection, dogs would need to receive both vaccines until a bivalent vaccine is manufactured, which likely will take several years to do.  A vaccine is not available for cats.