Almost a year after the outbreak in Chicago, we now know a lot more about Canine Influenza. Most importantly, we know now that there is no cross protection between the strain we have been vaccinating for (H3N8) and the most recent outbreak strain (H3N2). One originated in horses, and the other in birds, and the viruses are distinct.
Within the last couple of months, two conditionally licensed vaccines for the newer strain have become available. Conditional licensure means they have not yet been proven to be effective, but they are safe with reasonable expectation of effectiveness. The companies have of course done their own studies that show good results. Even the fully licensed H3N8 vaccine is indicated for control of disease and decreased viral shedding, not for prevention of disease or shedding, so these vaccines will not perfectly protect all dogs, but they should decrease severity of disease when dogs are infected, and the vaccines have a manufacturer guarantee that covers testing and treatment for dogs that become infected after proper/complete vaccination.
There are no big outbreaks in our area (IN/IL/WI/OH), but there are still a few cases being reported in the Midwest. We will continue to keep track of this.
Unfortunately, because this is a hospital first, with boarding and grooming also located here, we cannot simply turn away sick animals to avoid contamination, as some kennels are advertising that they do. Moreover, dogs can shed virus even if they never get sick, for several days prior to onset of signs, and for up to two weeks after they stop showing symptoms if they do get sick, so the absence of symptoms does not guarantee that no spreading of virus is taking place.
So, what does this mean for our boarders and patients?
We will continue to require influenza vaccination for our boarders. For maximum protection, this should be given two weeks prior to a boarding stay. We know that many of you are in here frequently and a two week lead time is difficult, but this will provide the best protection for all of our guests if we can do this for as many dogs as possible.
- For boarding dogs that have never been vaccinated, we will begin vaccination with the new strain (H3N2). This requires a two-dose initial series, with doses given 2-4 weeks apart, similar to the H3N8 vaccine that we have been using. There are no known outbreaks of H3N8, but American Animal Hospital Association still recommends vaccination with both strains for best protection. Due to financial considerations, we will not require both vaccines unless there are further reports of H3N8.
- We are recommending that ALL of our boarders and frequent grooming dogs start vaccination with this new strain as well. Again, this is a series of two injections regardless of previous vaccination with H3N8. Because we know that two additional vaccines adds a lot to the cost of boarding, we will continue to accept current H3N8 vaccines as adequate, until the new vaccine is fully licensed OR there are increasing reports of new cases.
- We have reason to believe that once the new vaccine is fully licensed, the manufacturer will be able to release a combination product with both strains, which will be our preferred product assuming nothing changes as far as new strains. Dogs that have been previously vaccinated with both one-strain vaccines will need just a yearly booster of the combination. Dogs that have had only one strain will require two doses for full protection.
- Merck (manufacturer of our H3N8 vaccines) will continue to pay for testing and treatment for dogs that develop H3N2 influenza, if they have been vaccinated with either H3N8 or H3N2, through the end of this year. This does NOT mean that previous H3N8 vaccines are protective, but it does give you some financial fallback in case of infection.
Thank you for allowing us to care for your pets, and for helping us decrease the risks of disease for all of our guests!