Canine Influenza – Are my dogs at risk?

Canine influenza or the “dog flu” is an Influenza A virus that affects dogs and causes respiratory signs such as coughing and discharge.  Canine influenza was first identified in Florida amongst racing greyhounds in 2004 the H3N8 strain which is thought to have spread from horses to dogs. This virus spread to other parts of the country after the many canine victims of Hurricane Katrina in 2006 were shipped around the country for rescue. A vaccine for this virus was developed in 2009.  The virus is highly contagious but like any strain of influenza the right circumstance of density, shared germs and stress determine whether an animal contracts the disease.  Dogs in boarding facilities and kennels are therefore more susceptible to contracting the flu.

In 2015 a new strain of Canine influenza H3N2 emerged in Chicago affecting dog daycare facilities and requiring some to temporarily close.  It is thought to be mutated from an avian influenza virus reported in the Asia in 2006.  It has since been identified in many parts of the country.  Clinical signs include coughing, congestion, eye and nose discharge and in some cases a fever.


Currently there is a low risk of canine influenza in California and the central coast- however the constant movement of people and their pets within the country makes it a possibility at any time.  The virus is spread through airborne viral particles during coughing and barking.  Clinical signs can range from very mild to more serious including the need for hospitalization.  Vaccination is recommended for pets who frequent daycare, grooming or boarding in areas where the virus has been identified. 

Here are further links to learn about the Canine influenza virus including a map of confirmed cases of the H3N2 strain from Cornell university:





Blog Post Author:
Merrianne Burtch, DVM, DACVIM