Canine Influenza Virus: Current Information and Recommendations

By December 8, 2016Dog Health


Canine influenza is an emerging concern for veterinarians and dog owners alike, so we wanted to share some information and our recommendations regarding this disease.  What we call Canine Influenza Virus (CIV) is actually caused by 2 different sub strains of the influenza A virus, H3N8 and H3N2.  H3N8 is an older strain that is similar to a strain found in horses, that may have infected racing Greyhounds starting back in 2003.  H3N2 is a newer strain of a bird flu originally found in Korea, that caused the rapid outbreak across many states in 2015.  The biggest concern to us veterinarians is that very few dogs have ever been exposed to either strain of flu, and therefore nearly 100% of dogs that are exposed, are fully susceptible to the virus.  In Michigan, we had a couple of confirmed cases last year, and at least one this year.

What do dog owners need to know?

First, the dogs that we see as the most high risk for contracting CIV are dogs that are around other dogs, such as; working dogs, show dogs, dogs that go to grooming, day care, or boarding facilities, dogs in shelters, and even dogs that visit dog parks. Any environment where large numbers of dogs are either held, or are in and out of, are the perfect breeding grounds for both strains of CI virus.

CIV is highly contagious and is spread from dog to dog in several ways. One way is through contact with an infected dog, especially contact with the respiratory discharge from that dog.  Whether they are showing symptoms, or not, it doesn’t matter, as they are still capable of transmitting the virus.  Another way is through the air, like from a cough, sneeze, or even a bark.  Finally, they can also become infected with CIV through contact with contaminated objects, like food bowls or clothing.  The incubation period is fairly short, at 2-4 days post exposure.  While CIV can occur any time of year, we tend to see outbreaks at times of the year when grooming and boarding are more common, like around the holidays.

Hygiene is extremely important in decreasing the spread of CIV, when visiting other dogs. Always be sure to wash your hands well, in soapy water, or at the very least use an alcohol based hand sanitizer.  In high risk environments, it is advisable to even change clothes and shoes.


  • Coughing — either dry and non productive, or wet and producing mucous
  • Sneezing
  • Discharge from Eyes and/or Nose
  • Loss of Appetite
  • Lethargy


Treatment of CIV is based on treating existing symptoms and providing supportive care.  Some dogs with mild CIV may need no treatment or can be treated at home, while dogs with the more serious form will need to be hospitalized.  The most important part of treatment is getting it started quickly.


Based on current data, 80%-90% of dogs exposed to the virus will develop influenza, with most of them having mild symptoms.  Up to 20% of infected dogs will progress on to having the more severe form of influenza, leading to pneumonia, of which 5%-8% will die.

What Do We Recommend

CIV has been found in 40 states across the United States, with Michigan having had some cases in the last year, and Illinois continues to have cases.  We expect this virus to continue to move across all 50 states, and to become more active in our state.  Does this mean we recommend that all dogs should be vaccinated for CIV?  Not necessarily.  At this point, we would recommend vaccination if your dog participates in activities that make them higher at risk for contracting the virus.  These include working dogs, dogs that participate in agility, flyball, dog shows, or other competitions, dogs that go for grooming, day care or boarding, dogs exposed to shelter dogs, or dogs that go to dog parks.  One other recommendation is, if you are going to vaccinate your dog, that you should vaccinate for both strains.

The most important thing to be mindful of, especially when vaccinating for CIV for the first time, is the timing of vaccination.  If a dog has never been vaccinated for CIV before, they need a series of 2 vaccines that are given two to four weeks apart, and then full immunity isn’t reached for at least 2 weeks after the second vaccine.  Once the initial series of 2 vaccines, the vaccine needs to be boostered annually to maintain immunity.  Bottom line, if your dog is going to be in a high risk situation, you need to plan ahead to make sure they are protected, and then keep up with annual vaccines to make sure we keep them protected.

What You Should Do If You Think Your Dog Has CIV

The first thing you should do, if your dog has upper respiratory symptoms, like coughing, sneezing, or nasal discharge, is keep them away from other dogs.  Whether it is CIV, or some other respiratory infection, you want to limit their contact with other dogs to avoid spreading illness.

The next thing that should be done is, have your dog examined by a veterinarian right away, because the key to successful treatment is getting it started immediately.  In order to protect other dogs that may be at the veterinary clinic, if at all possible, leave your dog in the car until you have checked in with the front desk staff to let them know what symptoms your dog is having.  That way, the spread can be contained as best as possible.

CIV is a highly contagious set of viruses that can affect any dog, regardless of age, breed, sex, or health.  Our focus, in these early stages, is education and prevention.  Please feel free to contact us if you have any questions or concerns about CIV and your dog, (810)635-4015