by Jess Franklin, DVM
As of 4/4/2015, there have been more than 1000 reported cases of dogs sick with canine influenza in Chicago. So far, Ann Arbor Animal Hospital has not seen a case of canine influenza, and we are not seeing any increase of contagious coughing in dogs. Our last extensive testing 2 years ago for viral and bacterial causes for coughing dogs did not demonstrate any influenza titers to our sick dogs. This means that our dogs are highly susceptible to canine flu.
In contrast to our typical Bordetella-related contagious canine cough, influenza is rapidly spread. Some of the patients will be very sick with pneumonia, and antibiotics do not have a direct effect on influenza virus infection. Fortunately, most dogs will recover with rest and supportive care.
Chicago is 4 hours away by car, and family members may bring their dog family to visit here. This disease is highly contagious, and our resident dog population is not currently vaccinated or protected by previous exposure.
Try to avoid contact with the Chicago dog population. If you are traveling, leave your dog here; if a family member from Chicago is planning to come here, we recommend they plan to not bring a Chicago dog here.
Vaccination is possible but there is a delay in immunity. Two vaccine injections need to be administered the first year, at least 2-4 weeks apart, and protection would be considered effective 7 or more days after the second vaccine. That leaves a minimum of 21 day lag time. The second year or annual booster is a single injection, and protection might be sooner than 7 days post-booster. So far, it is the experience of veterinarians working for both vaccine manufacturers, Merck and Zoetis, that the vaccine is effective if given before exposure in lowering symptoms or preventing the disease. There does not appear to be a problem of canine influenza vaccine becoming ineffective because of virus strain change from outbreak to outbreak.
More recent information has surfaced about this current strain of canine flu. Vaccines offered currently by Zoetis or Merck are not effective in protecting against the current strain. The vaccines are however, well tolerated and may provide some benefit. The current strain of flu is h3n2 and the vaccines were created to treat h3n8. Please see our most recent article about the canine flu or visit Cornell University's website.
I am conservative about vaccines, and do not recommend vaccinating every animal for every disease, but I expect Chicago’s problem will be here soon. Dogs at play groups, dog parks and boarding are at highest risk. We now stock canine influenza vaccine, and recommend it for the public mixing dogs.