The Canine Flu(s) Blues

By Robert J. Weiner VMD DABVP (canine and feline)
County Animal Hospital, New City, New York

If you are traveling on vacation it is possible your dog will also be vacationing at a boarding facility. Perhaps your dog enjoys meeting other dogs in the park or goes to doggie day care. If so, it is likely that at some point your dog will bring home “infectious canine cough”, also known as kennel cough. Infectious canine cough is not caused by a single agent and veterinarians cannot immunize against all possible causes. We do vaccinate against the most serious agents. These include Bordetella bronchiseptica (same genus as the bacteria that causes whooping cough in children), canine distemper virus and canine parainfluenza 3 virus.

Similar to the situation with humans the list of infectious agents that affect our dogs is constantly evolving. In 2004 veterinarians first became aware of canine influenza. At that time a strain of Influenza A, H3N8, was identified. This was an equine flu virus that mutated and was able to infect dogs. It was isolated from Greyhound race tracks in Florida. Dogs had no prior experience with influenza and as a result the virus spread rapidly across the country in epidemic fashion. Many dogs died. A vaccine was developed. H3N8 has pretty much disappeared except for the Northeast where self-limiting outbreaks occasionally occur. In 2015 an outbreak of a flu-like illness occurred in the high-density animal shelters in Chicago. The Animal Diagnostic Laboratory at Cornell University veterinary college identified a new strain of Influenza A, H3N2. This outbreak has continued in the Midwest and this year there have been outbreaks of H3N2 in Florida, Texas and North Carolina. A few cases have been reported in Chemung County in New York State. This newer strain is a bigger problem than H3N8 because dogs shed the virus and are contagious for a much longer period of time. As of the date of this writing (August 2017) it has not been reported in Rockland County, but one imagines that it will arrive here eventually. There is now a vaccine for H3N2 and a bivalent vaccine that immunizes against both strains, which makes sense in the Northeast. Canine influenza is not contagious to humans, but H3N2 can affect cats. There is no influenza vaccine for felines.

Veterinarians generally recommend influenza vaccine for those dogs whose lifestyle frequently puts them in contact with other dogs.

For more information about canine influenza see:

As published in the October 2017 issue of New City Neighbors Magazine