Don’t Let the Flu Get Your Dog Down

When I first started working in the veterinary field “doggy flu” was a fictional disease. Unfortunately, this fiction has become a reality in the past couple of years.


Canine Influenza Virus was first identified in racing greyhounds in Florida in 2004. It was initially a strain that mutated from horse influenza that jumped from horses to dogs. There is another strain of the virus that mutated from an avian influenza virus that jumped from birds to dogs. These strains have been primarily found in the US and other parts of the world.

In January 2018, two dogs who were shipped to Canada were confirmed to have the Canine Influenza Virus. These two dogs are the first confirmed cases of the illness in Canada. This disease will likely be diagnosed more and more frequently. I am going to discuss the virus – how it’s transmitted and signs and symptoms to look out for – in this blog.

Canine Influenza Virus is similar to the human flu, but it is not contagious to humans. As I mentioned earlier, the virus has been around for several years. In fact, there have been multiple outbreaks of this disease in the US, but it is only recently that the virus landed on Canadian soil. Canine Influenza Virus has an aerosol transmission. This means that the disease is transmitted through barking, sneezing and coughing. The virus can also be spread indirectly through objects or people who have been in contact with an infected dog. Dogs that come into close contact with infected dogs are at greater risk of catching the virus. The virus is contagious for 48 hours on surfaces, on clothing for 24 hours and hands for 12 hours. That’s why it is so important to wash hands and clean surfaces and clothing if they have come into contact with a dog who is exhibiting clinical signs associated with the disease.

Unfortunately, sometimes dogs can have a subclinical infection (which means they aren’t exhibiting signs). Dogs are most contagious to other dogs during the incubation period, which ranges from 1-8 days (depending on the strain) after infection. Virtually all dogs exposed to Canine Influenza become infected. Just as with the flu seen in humans, Canine Influenza Virus causes an acute respiratory infection in dogs. Unlike the human flu, there is no ‘season’ for the canine flu and infections can happen at any time of the year. Some common symptoms include a cough, nasal and/or eye discharge, sneezing, lethargy and decreased appetite. Fever is another common finding. These symptoms are very similar to Canine Kennel Cough so diagnosis cannot be done by clinical signs alone.

Fortunately, the vast majority of dogs who contract Canine Influenza Virus have mild symptoms and deaths from this disease are extremely rare. Unfortunately, some dogs develop very severe signs and can succumb to this illness. That is why it is very important to bring your dog to the hospital if any clinical signs become apparent. Treatment for Canine Influenza is mostly supportive because this is a virus and the dog’s immune system has to fight it on its own.

Secondary bacterial infections in the respiratory tract can occur with this illness, so occasionally antibiotics are used to treat dogs with nasal or eye discharge or secondary lung infections. Anti-inflammatory drugs are used to treat fever and inflammation.

Making sure that your dog is eating and drinking properly is critical during the treatment of this illness. Canine Influenza Virus will likely become more prominent in Canada in the next few months. Please speak with us if you are concerned about this disease and we can perform a risk assessment on your dog. We’re just keeping it flu real!

Written by Shanon Chase, RVT