With more and more people turning to natural remedies for both themselves and their pets, many dog owners are calling into question the need for an annual canine flu vaccine. So does your dog really need the vaccine? And what should vets tell their clients to help them make an informed decision?

First, it’s important to remember that in the case of canine influenza, the individual dog does make a difference. The AVMA considers the canine influenza vaccine a “lifestyle vaccine”, meaning not every dog will need it. Rather, the need for the vaccine depends on a dog’s overall health and risk of exposure.

Catching the Disease. Just like kennel cough, canine influenza is incredibly contagious and can spread through highly populated environments like wildfire. If a dog spends a lot of time at a boarding, groomer, or doggie daycare facility, or has recently been adopted from a shelter, he stands a much higher chance of being infected and is an excellent candidate for annual vaccination.

Morbidity vs. Mortality. The canine flu is a relatively “new” virus in the United States, and so most dogs have no natural or vaccine-induced immunity to the disease. In other words, since most dogs have never been exposed to the virus, their bodies will have trouble fighting it off. The AVMA estimates that around 80 percent of dogs infected with canine influenza will develop minor symptoms, with 10-20 percent developing more serious symptoms and complications, such as pneumonia. However, while the morbidity rate for canine influenza (i.e. the number of dogs who become ill) is quite high, the disease’s mortality rate (i.e. the number of dogs who actually die from the illness) remains low. Understanding this difference between morbidity and mortality can help pet owners better understand the risks of canine flu and decide whether their dog truly needs the vaccine.

Deciphering the vaccine. There are lots of conflicting opinions circulating about the canine flu vaccine, both for and against, so it’s important that dog owners understand exactly what the vaccine does and does not do, as well as its potential risk factors. Currently, the canine flu vaccine protects against the H3N8 strain of influenza. It isn’t clear whether the vaccine protects against the newer H3N2 strain. The flu vaccine does not prevent infection entirely; rather, it lessens the severity of flu symptoms in dogs and help the animal fight the infection more quickly and effectively. In terms of risk factors, the canine influenza vaccine is extremely safe for healthy dogs with no underlying diseases. However, smaller dog breeds are more likely to experience side effects from the canine flu vaccine, such as fatigue, diarrhea, vomiting, and pain at the injection site.

Location, location, location. The H3N8 strain of canine influenza has been reported in 40 states and the District of Columbia and is endemic in areas of Colorado, Florida, New York, and Pennsylvania. The H3N2 strain first appeared in the Chicago area and is most common in the Midwest; although it has spread to other areas of the US, it has not yet become endemic in any particular region. All healthy dogs should receive an annual canine flu vaccine if they live in an area where cases of canine influenza are common or where there has been a recent outbreak of either strain of the virus. Similarly, if a pet owner travels regularly with their dog to areas where canine influenza is common, that dog should receive the vaccine as well.

Vaccination is a hot topic these days, especially when it comes to optional vaccines like the canine flu shot. It’s important for vets and dog owners to have an open dialogue about the shot and about each dog’s individual needs. This can help remove the controversy and make dog owners more comfortable and more likely to comply with their vet’s recommendations.