If you follow the news or take your pet to boarding or day care facilities routinely, you may have heard about the canine influenza virus.  This virus is actually a fairly recent discovery in the veterinary world.  There is also still a lot being learned about it.  For these reasons, there are a lot of pet parents who have questions about this disease.  In this post, we take an opportunity to share what is known, so far, about canine influenza.  The better we understand this disease and how it affects our beloved pets, the more we are able to protect them and minimize future outbreaks.

What is canine influenza?

Canine influenza is a flu virus that behaves similarly to the human flu virus, but affects dogs.  It is caused by an influenza A virus, and there are currently two known strains.  The first strain, H3N8, was identified in Florida in 2004, in racing greyhounds.  It was thought that this strain developed from the equine H3N8 and jumped from horses to dogs.  The second strain, H3N2 originated in Asia and was first isolated in the US in 2015 from dogs living in the Chicago area.  Since this time, both strains have spread to several other states. Florida has had multiple reported outbreaks of both the H3N8 and H3N2 versions of the virus. 

Can I get canine influenza?

While canine flu is an influenza virus, it is a different strain than the typical human influenza viruses.  To date, there has not been any known transmission of flu from dogs to people.  However, in 2016 there was a report of several cats in an Indiana shelter contracting the H3N2 canine virus.  Given that occurrence, and knowing the original strain was thought to come from horses, it is still a concern that canine influenza could transmit to other species.  This may be more likely in environments with consistent close contact between dogs and people and lower hygienic standards.

How does my dog get canine influenza?

Like in humans, flu is spread via respiratory secretions like what escapes through a cough or sneeze. Therefore, this illness is more likely to spread in environments where dogs are kept in close quarters to other pets.  Shelters, boarding facilities and dog parks are prime examples of at risk locations.  Items contaminated with these secretions such as water bowls, bedding, leashes or even people moving between infected and uninfected dogs can also help spread disease. 

Once a pet has contracted the flu virus, there is usually a 2-4 day incubation period where they will not show any signs of illness.  However, pets are still quite contagious during this window.  After this 2-4 day window, some pets will become sick.  However, roughly 20% of pets will not get sick, but remain contagious for up to 7 days.  It is because of these asymptomatic (showing no signs of illness) pets that this virus can be so difficult to contain. 

What are the symptoms of canine influenza?

The most common symptom of canine influenza is a persistent (1-3 week) cough.  This symptom occurs in up to 80% of dogs who have been exposed to the virus.  Other symptoms of flu are thick nasal discharge, fever, lethargy, eye discharge and decreased appetite.  Because all of these symptoms can be found in pets with canine infectious tracheobronchitis (Kennel Cough), flu is commonly mistaken for this disease in the early or mild form.  Some people may ask, “what makes the flu different?” The significance of a canine flu infection is that it compromises the normal defense mechanisms in the respiratory tract.  This creates a huge risk for secondary bacterial infections and pneumonia.  While it is rare (<10%) some pets can even die from the flu and it’s complications.

How do we test for canine influenza?

If a new cough is noted, it is recommended to have your pet examined by a veterinarian.  This is especially important if he has had recent exposure to other dogs or spent time in a boarding or daycare facility.  If there is concern for flu, the veterinarian may recommend taking a sample nasal swab and sending it to the lab for testing.  It is important that this particular test be done within the first 4 days of illness, otherwise it may no longer be able to detect the virus, even if that was the cause of disease.  There are also blood tests that can be done later in the disease to see if a pet has been exposed to flu in the past.

How do we treat canine influenza?

There is no specific treatment for canine flu, but many pets will require some supportive care for their fever, dehydration or decreased appetite.  They may also need treatment of secondary bacterial infections such as pneumonia.  In severe cases, pets may need to be hospitalized for a few days.  Because the flu is highly contagious, it is imperative that any ill pets be isolated as best as possible during their treatment.  The flu virus typically sheds for 7 days, so a full week of isolation is recommended to prevent other pets from contracting the disease.  When the H3N2 strain of the virus is confirmed, it is recommended that some pets be isolated for up to 21 days.  Thorough treatment of any bowls, bedding and containment areas is also very important in preventing spread.

How do we prevent canine influenza?

There are vaccines available for canine influenza. The older version of the vaccine covers for just the H3N8 strain, since it was the first discovered.  The newer version of the vaccine covers for both the H3N8 and the H3N2 strains.  This is the version of the flu vaccine most commonly recommended for pets at risk.  This particular vaccine is recommended for the same reasons a Bordetella vaccine would be recommended such as visits to boarding or grooming facilities, social events with dogs and dog parks.  If your pet has never been vaccinated for the flu, an initial vaccine is given, then boostered 2-4 weeks later.  While there is still a lot of investigation into how often this vaccine needs to be administered, it is typically given annually thereafter.

How can we help?

If you feel your pet may benefit from the flu vaccine, or you have more questions regarding this disease or the prevention, the vets and staff at West Park Animal Hospital would be happy to help. As always, the veterinarians at West Park Animal Hospital want you to feel comfortable with the care your pet is getting. We’ve designed all of our appointments to provide ample time to discuss all of your concerns and answer your questions. What is most important to us is that we provide your pet with the highest level of care by creating an individual plan for each of our patients. If you’d like to discuss more about your pet’s needs, call us at (813) 749-6863 for an appointment or conveniently schedule one on our website.