Canine Influenza: What to Do When Your Dog is Under the Weather

By Chelsea Hunt-Rivera / May 28, 2018
Canine Influenza

What is Influenza

Influenza, often referred to as the flu, is a profoundly contagious, viral infection that affects the respiratory passages, specifically the lungs, nose, and throat. Influenza commonly causes severe aching, fever, and excessive buildup of mucus in the throat and lungs. The flu typically occurs in widespread epidemics. Without appropriate treatment, influenza can lead to death.

Canine Influenza

Can Dogs Get The Flu

Yes. Canine influenza exists and is something that all pet owners should be implicitly aware of in order to prevent their dog from contracting the disease.

Furthermore, while the canine influenza virus can stand alone, it is commonly involved with additional infections. The combination of these infections can lead to an illness known as Kennel Cough. Ensuring that you know the causes and symptoms of the CI virus can also help protect your dog against secondary ailments.

What is H3N2

In the United States, two strains of canine influenza virus (CI virus) have been reported. The first strain recorded in 2004 was an H3N8 influenza A virus. The strain is very comparable to an equine strain of the influenza virus that has been recognized in horses for over 40 years. Experts believe that a mutation occurred in the equine strain and produced the canine strain of the virus.

In 2015, a strain of canine influenza termed H3N2 caused an outbreak of the virus in Chicago. The strain responsible for the outbreak was nearly genetically identical to a strain that had only been reported in Asia up until that point. Experts believe that the strain was a result of an avian influenza virus (likely from live bird markets) passing directly to dogs in Korea, China, and Thailand. However, since the 2015 outbreak, there have been thousands of dogs diagnosed with H3N2 canine influenza across the United States.

Types of Canine Influenza

Most veterinarians will diagnose a dog with one of two forms of the virus: Mild or Severe. The severity of the illness will dictate several important factors including the symptoms that are present and treatment that will be necessary for the dog to make a full recovery.

Canine Influenza SymptomsCanine Influenza

General symptoms of the canine influenza virus include:

  • Coughing
  • Sneezing
  • Loss of appetite (anorexia)
  • Fever
  • Nasal discharge
  • Red, itchy eyes
  • Overall body aching and physical distress

Symptoms of Mild Forms of Canine Influenza

Dogs with a milder form of canine influenza often have a typically wet cough and a thick, green, mucusy nasal discharge. Occasionally dog owners report a dry cough, but not often. Dogs infected with milder forms of the CI virus will commonly develop secondary bacterial infections, usually a bacterial upper respiratory infection.

Symptoms of Severe Forms of Canine Influenza

One of the first clinical signs of a severe form of the CI virus is a high fever (over 103 degrees Fahrenheit). If the dog is infected with a severe form of canine influenza, symptoms will typically develop rapidly and need immediate medical intervention.

A dog that does not receive immediate, appropriate treatment is at a high risk of developing pneumonia (specifically hemorrhagic pneumonia). Bacterial pneumonia will lead to further complications and difficulties in treating the dog.

H1N1 (Swine Flu) Influenza Symptoms in Humans vs. H3N8 Dog Flu Symptoms

In several ways, the H1N1 virus in humans and the H3N8 virus in dogs are comparable.

Both of the viruses are mutations from one species to another. Additionally, both viruses are new infections, neither humans or dogs had been exposed to the virus before. Furthermore, the H1N1 virus and the H3N8 virus both cause similar symptoms including fever, nasal discharge, coughing, lethargy, and an overall aching of the body.

Causes of Influenza Virus in Dogs

The most prevalent way for the CI virus to spread is through respiratory secretions contaminating common areas. A dog’s respiratory secretions from coughing, sneezing, and nasal discharge can easily contaminate objects such as food and water bowls, the walls and floors of kennels, collars and leashes, and clothing and skin of their owners.

The CI virus can survive on surfaces for up to 48 hours, on clothing for 24 hours, and on the skin for up to 12 hours. Any dog that comes in contact with the contaminated object is at risk for contracting the CI virus.

Is the Flu Contagious

Canine influenza is extremely contagious. If your dog comes in contact with the virus there is a high probability that they will become infected.

Canine Influenza

Canine Flu Incubation Period

The incubation period for the canine flu is approximately two to four days. In other words, it generally takes two to four days after contact with the virus for dogs to begin showing clinical signs of contracting influenza.

Is the Influenza Virus Zoonotic?

If a disease is zoonotic, it can be transmitted between animals and humans. There is presently no evidence proving that the canine influenza virus is zoonotic although there is a possibility of the virus changing over time.

A notable occurrence in which influenza was classified as zoonotic was the 2009 outbreak of the H1N1 virus, better known as Swine Flu. In the case of H1N1 influenza, humans contracted the virus from pigs (swine). Subsequently, dogs, cats, and ferrets then died after contracting H1N1 from humans.

Diagnosing Canine Influenza

In order to diagnose canine influenza, your veterinarian will first administer a physical exam and order a blood test (often a complete blood count or CBC).

Canine Influenza

Because the clinical signs of canine influenza closely resemble symptoms of other illnesses, additional extensive testing will be necessary for an accurate diagnosis.

The additional tests may include:

  • Chemistry tests
  • Electrolyte tests
  • Urinalysis
  • X-rays

These tests will be able to rule out other conditions, such as certain infectious diseases, as well as give the veterinarian information on how the kidneys, liver, and pancreas are functioning.

Treating Canine Influenza

There is not a specific treatment plan for canine influenza. Comparable to the flu diagnosed in humans, canine influenza generally has to run its course before the dog starts feeling better.

In mild cases of canine influenza, treatment may be as simple as resting at home and monitoring the illness to make sure it doesn’t get worse. If the dog’s coughing is severe, veterinarians may prescribe cough suppressants to soothe the dog’s throat. Additionally, if the dog has developed a secondary bacterial infection, antibiotics will be necessary as well.

A dog infected with a severe form of the canine influenza virus may require hospitalization and treatment with intravenous fluids, antibiotics, and oxygen therapy.

Sadly, severe cases of the CI virus may end in the death of the dog, despite treatment.

Canine Flu Duration

In most cases, symptoms of the canine influenza virus will last between 10 and 30 days.

Preventing Dog Flu

Because dogs do not have naturally acquired immunity to the virus, they are all at risk of contracting influenza. So what can pet owners do to prevent their dog from becoming ill with the CI virus?

First, be aware of any influenza outbreak in your area and act accordingly. Make sure to keep your dogs bowls clean. Also, avoid contact with objects that other dogs may have contaminated.

Additionally, pet owners should understand the potential risks involved with regularly boarding their dog as kennels can be a breeding ground for canine influenza.

Canine Influenza

What Dog Owners Should Know About The Canine Influenza Vaccine

It’s very possible that your veterinarian has tried to sell you on vaccinating your dog with the canine influenza vaccine.

First of all, dog owners should understand that the canine influenza vaccine does not completely prevent the disease. The vaccine is geared to minimize symptoms and reduce the risk of shedding the virus. In this sense, the vaccine helps to decrease future outbreaks.

However, with all vaccines, the CI virus vaccine comes with its own set of risks. Before jumping to vaccinate against canine influenza, dog owners should first consider their dog’s individual risk. Dogs with limited exposure to other dogs and indoor dogs who do not frequent boarding facilities or dog parks are at a much lower risk of contracting the virus.

The best thing to do is talk to your veterinarian about your dog’s risk of contracting the CI virus and deciding whether the vaccination is necessary. Your

Canine Influenza

veterinarian will also be able to provide information about how common canine influenza is in your particular area.

Canine Influenza: A Final Thought

When pet owners can fully recognize just how awful a virus can be, it can be scary to imagine it infecting their fur baby. Regardless of who it’s affecting, the flu is nothing to shrug about. The virus’ horrific symptoms and its ability to be quickly spread are among the many reasons why dog owners should be on high alert for potential signs and causes. Talk to your veterinarian about the best way to prevent your pup from contracting the virus.


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About the author

Chelsea Hunt-Rivera

Chelsea Rivera is a Dedicated Pet Parent who loves to create amazing content for pet owners and is helping change pet wellness as the Head of Content for