Bridget Andersen, DVM

Approximately 4 months ago there was an outbreak of a strain of the Canine Influenza virus in the Chicago area.  While it was first believed that the virus was the same Influenza strain (H3N8) first isolated in Florida in 2004, subsequent studies have shown that this outbreak is more closely related to the Asian strains of Influenza A H3N2.  These viral strains have been affecting dogs in China and South Korea since 2006 and this virus outbreak likely came from that region.

Since the outbreak in Chicago was confirmed with a broadly targeted Influenza-A matrix PCR test, cases have also been confirmed in other parts of Illinois, Wisconsin, Indiana, Michigan, Minnesota, California, New York, New Jersey, Ohio, Iowa, Georgia, and Alabama.  Both strains of  Influenza virus (H3N8 and H3N2) cause coughing, nasal discharge, high fever, loss of appetite, and lethargy.  The clinical signs of H3N2 may be more severe as this may be a more virulent strain based on the widespread nature and short time frame in which the virus spread.   While thousands of cases have been confirmed, only 6 dogs have died from the virus.

There is a vaccine developed to protect dogs from the H3N8 strain of the virus.  It is unknown whether the currently available canine H3N8 flu vaccines will protect dogs against the H3N2 strain.   However, at this time it is recommended to vaccinate high risk dogs against the H3N8 strain with the currently available strain because the H3N8 strain is still a risk, and because there might be some cross protection against the H3N2 strains of the virus.   High risk dogs include dogs with high exposure to other dogs such as doggy day care, dog parks, boarding facilities, dog shows, sporting events, and dogs living in inner cities.

Currently at Animal Medical Hospital, we are only recommending the vaccine for dogs or their owners who are traveling to endemic areas and are coming into contact with dogs in those areas.   If an outbreak of the virus is reported in North Carolina, we will likely change our protocol and we will notify our dog owners immediately.

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