In my home state of Florida where a significant but generally contained canine influenza outbreak occurred in 2017, most grooming shops, kennels, and agility facilities are still requiring participants to be up to date on the 2 strain canine influenza vaccines despite all signs indicating that the disease has run its course and is in the rear view mirror at this point. Some veterinarians are still recommending it as well. The questions remains, is there any merit in continuing the vaccination program when there is no current outbreak?
The short answer is, not really, but I do not necessarily disparage the aforementioned organizations for mandating a current vaccine. Liability and reputation is a major concern in this day and age and they are simply covering their rears in the event that a dog got sick with flu, they can point to their policy in proving that they are doing their due diligence to proactively engage in preventive protocols.
Realistically, however, we need to look no further than the Midwest for proof that a post outbreak continued vaccination protocol does little to prevent a new outbreak. The Midwest was hit particularly hard with the H3N8 canine influenza outbreak in 2015. Given the severe morbidity of that particular strain of canine influenza, many veterinarians and dog facilities continued to recommend yearly vaccine against the H3N8 strain. In 2017 when cases of a new H3N2 strain began to arise, there seemed to be no cross protection against the novel strain. In effect, the previous canine influenza immunization ultimately had little to no benefit in preventing the new strain of flu.
Luckily, the new strain was quickly identified and a two strain (for the previous H3N8 and the new H3N2) canine influenza virus was developed and put into production. The disease made its way to Central Florida as well, but between the prompt development and distribution of the vaccine and recognition by the dog show and dog agility circuits to by in large shut down events until the outbreak ran its course, the the 2017 canine influenza outbreak was generally well contained.
Given the highly mutagenic nature of the canine influenza virus, the predictability of the efficacy of a given strain is not very reliable. Thus in my opinion, there probably is little benefit in continuing to vaccinate for a canine influenza outbreak that seems to have run its course. Of course, I still vaccinate for it when requested, as it is usually requested as the result of the policies of a groomery, kennel or other facility that dogs frequent in large numbers that require the vaccine. From a general standpoint, however, I am not recommending the vaccine at this point. When canine influenza rears its ugly head again, it will most likely be a new strain.
Dr. Roger Welton is a practicing veterinarian and well regarded media personality throughout a number of subjects and platforms. In addition to being passionate about integrative veterinary medicine for which he is a nationally renowned expert, Dr. Welton was also an accomplished college lacrosse player and remains to this day very involved in the sport. He is president of Maybeck Animal Hospital , runs the successful veterinary/animal health blogs Web-DVM and Dr. Roger’s Holistic Veterinary Care, and fulfills his passion for lacrosse through his lacrosse and sport blog, The Creator’s Game.