Facts About Canine Influenza

Canine influenza, also known as dog flu, has been in the news again lately, following a reappearance in several states of the virus that affected over 1000 dogs in the Chicago area last spring. The recent outbreak at the start of 2016 has affected 80-90 dogs in the Seattle area as well as at least one dog in Montana.

Canine Influenza Virus (CIV) is a very contagious virus that began in horses and birds before spreading to dogs. Canine influenza is not typically fatal, and with treatment, the dog can recover fully within a week to a month. However in most severe cases (less than 10% of dogs who contract it), CIV can lead to high fever, pneumonia and death. Similar to our previous post on Parvovirus, we have pulled together some facts about canine influenza, how it’s spread, symptoms and treatment.

How is canine influenza spread?

As mentioned above, CIV is very contagious, and can spread from dog to dog through shared food bowls, toys or even the air around them. As a result, outbreaks often occur in places where numerous dogs come in contact with each other, including kennels, dog day cares and dog parks.

There are two known strains of CIV that have affected dogs in the US. H3N8 influenza A virus is closely related to an equine influenza virus and is believed to have first spread from horses to dogs at a racing facility in Florida in 2004. A second strain, H3N2, is the virus that caused the dog flu outbreak in Chicago in 2015 and is a close relative of an avian flu virus that first spread to dogs in Asia in 2006. One key difference between the two strains is that H3N2 has caused infection and respiratory illness in cats.

Even though it is highly contagious, CIV does not live long in the environment, so isolation of infected dogs and a thorough cleaning of the shared area can help limit its spread. (Note: According to the CDC, “there is no evidence of transmission of canine influenza virus from dogs to people.”)

What are the symptoms of canine influenza? How is it treated?

Symptoms of canine influenza include:

  • Coughing
  • Sneezing
  • Runny nose, with a yellow-green discharge
  • Lethargy
  • Loss of Appetite
  • In rare cases, fever and onset of pneumonia

It may take up to 10 days after exposure to CIV for symptoms to manifest. Some of these symptoms are similar to bordetella or kennel cough, however canine influenza often results in a “more moist cough than bordetella’s dry cough.” If your dog develops these symptoms, a visit to your vet is recommended as soon as possible.  The vet will also recommend that you keep your dog indoors and away from other dogs until they can determine the cause and begin treatment.

Treatment of the milder form of canine influenza (again, this is the more common form) includes rest, fluids and sometimes medication. The severe form often requires hospitalization. Again, dogs with canine influenza should be isolated from other dogs until they recover.

How can you prevent canine influenza?

“Preventing canine influenza or any other “kennel cough” relies on the same principles as humans trying to avoid the common cold,” writes veterinarian Dr. Ingrid Pyka. “Prevention depends on minimizing exposure to the virus.” This is not an easy thing to do, especially due to the fact that an infected dog may not show symptoms right away.

So should you avoid all possible locations like kennels, groomers and dog parks at all times? That doesn’t seem feasible, nor acccording to the American Veterinary Medical Association (AVMA), is it required, unless there is an established outbreak (like the one taking place in Seattle this month). The AVMA writes:

Dog owners should be aware that any situation that brings dogs together increases the risk of spread of communicable illnesses. Good infection control practices can reduce that risk, so dog owners involved in shows, sports, or other activities with their dogs or who board their dogs at kennels should ask whether respiratory disease has been a problem there, and whether the facility has a plan for isolating dogs that develop respiratory disease and for notifying owners if their dogs have been exposed to dogs with respiratory disease.
As long as good infection control practices are in place, pet owners should not be overly concerned about putting dogs in training facilities, dog parks, kennels, or other areas frequented by dogs.

As of November 2015, there are H3N8 and H3N2 canine influenza vaccines on the market that may be available from your vet. These vaccines are in addition to the “core” vaccines provided by your vet. Your vet may recommend this vaccine if your dog is at increased risk for disease due to various factors (frequent kennel boarding, recent outbreak in the area and others).

For more information about canine influenza, contact your veterinarian. To read more about canine influenza, its history and how it’s treated, here are some online resources:

Canine Influenza FAQs from the American Veterinary Medical Association (AVMA)

Key Facts about Canine Influenza (Dog Flu) from the Centers for Disease Control and Prevention (CDC)


Image Credit: “Let Sleeping Dogs Lie” by Fool4myCanon is licensed under CC BY-SA 2.0. Image is cropped.

This blog post is an updated version of a blog post first published in Dog Tails in April 2015.

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