Dear Dr. Hershey,
I am worried about the canine flu epidemic in Chicago, and the reports of flu spreading to our area.  Should I get my dog vaccinated for canine flu?

Thank you,
Iman.

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Dear Iman,

The Canine Influenza Virus (CIV) or “flu,” has been receiving a lot of attention lately, and has become an increasing concern for dog owners. CIV (strain H3N8) was first identified in Florida in 2004. It was found in a group of racing greyhounds and was thought to be a variant of the equine influenza virus. Since that time, cases of canine flu have been reported throughout the country.

The most recent outbreak of canine flu was in Chicago.  According to news reports, over 1,000 cases of flu have been confirmed, and there have been some fatalities due to the virus. Shortly after the outbreak occurred, the Chicago CIV strain was identified as a new strain of flu that has not previously been seen in the United States. It is flu type H3N2. Speculation is that this flu strain was brought over from Asia.  

The flu virus is highly contagious, and one of the problems is that dogs are most contagious during the first 48 hours, which is before they start to show signs of illness. Because dogs can spread the disease without their owners knowing it, quarantining of contagious animals to prevent spread is virtually impossible.  

Symptoms of canine flu can include cough, lethargy, fever and nasal discharge. Some dogs, especially the very young, very old, or immune compromised dogs, can develop severe complications, including life threatening pneumonia.  According to the American Veterinary Medical Association (AVMA), “Almost all dogs exposed to CIV will become infected, and the majority (80 percent) of infected dogs develop flu-like illness. The mortality (death) rate is low (less than 10 percent).”

As of May 5, there have been no confirmed cases of canine flu in Minnesota. However, there have been confirmed cases in both Wisconsin and Iowa.  It is very likely that flu will come to Minnesota. So what is a dog owner to do? They certainly don’t want their dog to become ill from canine flu, however, we know that the vaccine (H3N8) will not be fully protective over the Chicago flu strain (H3N2). Also, the vaccine needs to be boostered 2-4 weeks after initial administration, and the vaccine is not considered fully effective until 1-3 weeks after the booster shot.  

According to the University of Minnesota Veterinary Medical Center, “[Dog] owners should still consider vaccinating dogs that visit dog parks, are housed in kennels, or attend show events. Vaccination can reduce the incidence and severity of disease in dogs infected with H3N8, which continues to circulate in the U.S.”  We are also hopeful that the H3N8 vaccine will provide some immunity and perhaps lessen the severity of flu symptoms in dogs exposed to H3N2, although we do not know for sure if that will be the case. There is currently no vaccine available for the H3N2 virus. It is also important to note that the “Kennel Cough” vaccine does not protect against canine flu. That vaccine is for the respiratory bacteria, bordetella bronchiseptica.  

Every veterinarian is taking all of this information into consideration, and making a thoughtful recommendation to their clients about whether or not their canine patients should be vaccinated.  It is important that pet owners make an informed decision.  At Westgate Pet Clinic, we are recommending that all social dogs (dogs that visit dog parks, kennels, and dog shows) be vaccinated for CIV.  

Dr. Teresa Hershey is a veterinarian at Westgate Pet Clinic in Linden Hills. Email her your pet questions at [email protected].