Canine Influenza Update


You may have recently heard about the Canine Influenza outbreak in Chicago, Illinois. The strain responsible for the outbreak has been identified as the canine Influenza A H3N2 strain. To date, there are no reports of this strain of canine influenza in North Carolina. Prior to this Chicago outbreak, the H3N2 strain had only been identified in Korea, China, and Thailand. In 2004 the first canine influenza outbreak of a different strain, H3N8, was identified in Florida racing greyhounds; since that time canine influenza has waxed and waned in the news. Thirty states and Washington D.C. have reported cases of canine influenza H3N8 in the past 11 years. Outbreaks tend to occur in situations where groups of dogs are kept close together– for example racing tracks, kennels, shelters, and dog day care facilities. No human infections have been reported in association with either of the canine influenza strains. In Asia the H3N2 strain has also caused respiratory illness in cats.

Canine influenza is a highly contagious, emerging pathogen in dogs. Since this is a newer virus in the canine population, the majority of dogs do not have immunity. Symptoms are respiratory in nature (coughing, sneezing, nasal/ ocular discharge) and can also include fever, anorexia and lethargy, to name a few. Some dogs may not show signs at all but could still shed or transmit the virus. In dogs that become clinical, both mild and severe forms of the disease have been identified. Thankfully most dogs will develop the mild form. Treatment is symptomatic. It is important to note that the respiratory symptoms seen with canine influenza can be caused by many other factors besides canine influenza, so the presence of these symptoms does not confirm that canine influenza virus is the cause. If your pet is demonstrating signs of illness, the best thing to do is have your pet examined by one of our veterinarians.

A vaccine is available against the older H3N8 strain but no vaccine is available against the new H3N2 strain. Lawndale Veterinary Hospital is monitoring the new outbreak situation and waiting for a new vaccine to be available against H3N2. Deciding whether to vaccinate a dog against canine influenza is a lifestyle decision combined with assessing the prevalence of the virus in a given area. While Lawndale does not recommend the routine vaccination of dogs in our area, we encourage you to discuss any questions or concerns you may have.

A variety of informative resources are available on the topic of canine influenza (these sources were also referenced to support the content of this blog). Please refer to the links below for additional information.

AVMA (Canine Influenza Background)

AVMA (Canine Influenza FAQs)


Cornell University

University of Florida College of Veterinary Medicine

Author: Dr. C. Noureddine, DVM, MS

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