An Update on the Canine Influenza

You may have heard about outbreaks of “dog flu” affecting pets across the country. This highly contagious and, for some dogs, potentially serious respiratory infection is caused by canine influenza virus (CIV) H3N2 or H3N8. Chances are, if your dog is exposed to CIV, he or she may become infected. Dogs that are frequently in contact with other dogs may be at high risk of infection with CIV H3N2 or H3N8. This includes dogs that are boarded, enrolled in day care, often visit the local dog park, or even have contact with dogs while visiting the veterinary clinic. If you have a puppy, elderly or pregnant dog or a dog that is immunocompromised, you should take extra precautions. The good news is that our office now has a vaccine known as Vanguard® CIV H3N2/H3N8 which is available to help prevent disease associated with both types of CIV to provide maximum protection.
Please call our office to discuss your dog’s risk for CIV. This is particularly important if you plan to board your dog in the near future or regularly send him or her to a grooming or daycare facility. We’ll answer all your questions about dog flu and help you decide whether vaccination is right for your pet. You can also visit for more information.

Frequently Asked Questions

What is dog flu?

  • Dog flu is a contagious respiratory disease. It is caused by two specific Type A canine influenza viruses (CIVs): H3N2 and H3N8.

I’ve been hearing a lot about a new strain of dog flu. What does that mean?

  • The “new” strain, CIV H3N2, was identified in Asia in 2006 and in the U.S. in 2015 during a major outbreak of respiratory illness in Chicago.
  • The other strain of dog flu, CIV H3N8, was first identified in the U.S. in 2004.
  • In 2017, dogs in Florida, Georgia, North Carolina, South Carolina, Texas, Kentucky, Tennessee, Missouri, Louisiana, Illinois and other states were diagnosed with CIV H3N2.
  • Zoetis provides the Vanguard CIV H3N2/H3N8 vaccine for protection against both highly contagious strains of CIV.

What are the symptoms of dog flu?

  • Symptoms of dog flu may include reduced appetite, high fever, cough, runny nose and lethargy.
  • Dog flu symptoms are similar to those of other bacterial and viral causes associated with Canine Infectious Respiratory Disease (CIRD).
  • As with flu in humans, symptoms and severity of infection may vary from dog to dog.
  • Dogs with CIV H3N2 infection may show more severe signs than dogs with CIV H3N8, or they may show very mild signs of infection.

Is dog flu a very serious illness?

  • Both CIV H3N2 and CIV H3N8 are contagious, and nearly all dogs exposed to dog flu will become infected.
  • About 80% of infected dogs will show symptoms.
  • Both types can cause serious illness in dogs that are very young or very old, as well as dogs with weakened immune systems.
  • The death rate for dog flu in general is less than 10%

How is dog flu transmitted?

  • Dogs catch the flu from each other in some of the same ways we pass flu among ourselves:
  • Droplets from sneezing or coughing from an infected dog.
  • Contact with infected pets or objects at dog parks, day cares, groomers and more.
  • The virus can survive on your hands for up to 12 hours and on clothing for up to 24 hours — so even though humans don’t become infected or sick with CIV, we can still transmit the virus to dogs.

My dog has previously been vaccinated against CIV H3N8. Does that vaccine also help protect against CIV H3N2?

  • The CIV H3N8 vaccine has not been shown to cross protect for CIV H3N2.
  • When vaccinating dogs to help prevent respiratory infections, it is important to understand that vaccination does not guarantee that a dog won’t become infected. It should be anticipated that vaccination will help to reduce the severity of signs of infection and help to decrease the amount of time that dogs will be capable of spreading the infection.
  • Generally speaking, flu shots are specific for strains of influenza.
  • A single vaccine for both flu strains, Vanguard CIV H3N2/H3N8, is now available.

What treatments are available for dog flu?

  • Dog flu cannot be cured with medication.
  • Supportive care is available — sometimes it is as basic as making sure a dog is resting, eating and staying well-hydrated.
  • Sometimes antibiotics and other medications also are given to help ease signs of infection or guard against secondary infections.
  • Your veterinarian can talk with you about specific treatment options for your dog’s infection.
  • Keep pets with signs of respiratory infection away from other pets until your veterinarian tells you otherwise.

What else can I do to keep my dog safe?

  • If there is a dog flu outbreak in your area, exposure may be increased wherever dogs are in close contact, such as dog parks, pet day care centers and communal water bowls.
  • Wash your dog’s toys, bowls and bedding regularly.
  • When you’ve come into contact with other dogs, even if they don’t appear sick, wash your hands and change clothes before handling your own pet.
  • Avoid contact with sick or possibly exposed dogs, as the virus can persist on clothing and other surfaces for at least 24 hours.

What can I do to keep other pets safe?

  • If you are concerned that your pet may be showing signs of dog flu, contact your veterinarian and keep your dog at home.
  • Until you’ve received examination or test results from your veterinarian, keep your dog separated from other pets.
  • Wash your hands thoroughly after handling your sick pet.
  • Vaccinating your dog may also help to keep other dogs safe if there is a risk of a dog flu outbreak in your area.

Can humans catch dog flu?

  • There is no evidence that either CIV H3N2 or H3N8 can be transmitted to humans.

Can cats catch dog flu?

  • Yes, CIV H3N2 has been documented to cause infection and respiratory illness in cats.
  • There is no evidence that CIV H3N8 can lead to disease in cats.