Canine Flu: An Update

April 29, 2015

Dog flu/canine influenzaFor the last few months, veterinarians and dog owners in the Chicago area and other Midwestern states have been faced with an outbreak of canine influenza. Over 1,100 dogs have been diagnosed with the virus and sadly, some have died. First identified in an outbreak of what was believed to be “kennel cough” in greyhounds, the canine influenza virus was initially described in 2005. Canine influenza virus is just one of the causes of “kennel cough” which is really a general term for canine upper respiratory tract infections.

The canine influenza virus reported in 2005 is an H3N8 strain of the virus which has been documented nationwide. The current Chicago outbreak is caused by an H3N2 virus, which is the virus circulating in Asian dogs. Exactly how the Asian strain came to the Windy City is not currently known. Canine influenza seems to be moving east and cases have now been confirmed in the state of Indiana. Just yesterday, dog flu was diagnosed in Iowa.

Dog to Dog Transmission
Canine flu is transmitted from dog to dog and dogs can transmit it prior to showing symptoms of the virus. That feature of the disease is probably responsible for its rapid transmission within a population. Inanimate objects, leashes, collars, bowls and bedding used by an infected dog could be a source of infection for other dogs coming in contact with those objects. Petting a sick dog and then petting a healthy dog can also spread the infection.

Clinical Signs of Canine Influenza
The clinical signs of canine influenza run the gamut of respiratory disease. Twenty percent of dogs infected with the virus will never show any signs, but still can infect other dogs. Most dogs develop what we might think of as a cold– sneezing, runny nose and a cough. Dogs with the flu feel out of sorts with a fever and a poor appetite. About ten percent of infected dogs will develop a serious complication of influenza – bacterial pneumonia.

What precautions should dog owners take?

  1. Avoid doggie day care, the boarding kennel, the dog park, obedience classes and any other areas where dogs congregate. The canine flu spreads most rapidly in situations where many dogs come in contact with each other or with infected dogs’ coughs and sneezes.
  2. Wash your hands well. The canine influenza virus can live on human hands for 12 hours, unless they are washed with soap and water.
  3. Talk to your veterinarian about the canine influenza vaccine. The available vaccine is for the typical H3N8 virus. Because the virus in this outbreak is H3N2, we don’t know if the flu vaccine will protect dogs against this new virus, but it is being recommended in the Chicago area. The canine flu vaccine is like the human flu vaccine; it lessens signs of flu and shortens their duration, but does not prevent the disease.
  4. If your dog contracts the flu, wash bedding, dishes, leashes and clothing which can transmit the virus for up to 24-48 hours after coming in contact with a sick dog.
  5. Keep your cat away from your sick dog since the H3N2 strain can be transmitted to cats. The H3N8 strain is not believed to infect cats.

Fall Flu Season and Your Pets

November 7, 2011

Fall is here, and with fall comes the flu. Every fall our physicians urge us to be vaccinated against the flu to protect our family members and ourselves from contracting or spreading this year’s flu virus.

What about our pets? Why didn’t I start this post urging you to take your pet to the veterinarian for its annual flu shot? That is because, unlike the human influenza viruses, canine influenza’s occurrence is not seasonal. So, anytime is the right time to vaccinate your pet against this highly contagious disease. I have answered some commonly asked questions I receive during flu season.

What is Canine Influenza?
Canine influenza is a new disease which was first identified in Florida in 2003. It mutated from a horse influenza virus to an influenza virus infecting dogs. Canine influenza is now found nationwide.

Is my dog at risk for contracting Canine Flu?
Dogs at risk for canine influenza infection are social dogs, such as those that go to doggie day care, dog parks, dog shows or a boarding kennel — anytime of the year. If your dog is a social dog, a vaccine has recently been developed to protect against canine influenza, and your veterinarian will know if it is right for your dog. The protocol for vaccination is two doses of vaccine given two weeks apart, followed by annual revaccination.

What about cats? I have heard about a Feline “Flu.”
Feline flu is a misnomer. Frequently called feline flu, feline herpes virus and feline calicivirus infections are not caused by an influenza virus and are not technically “flu.” No influenza virus has been identified in cats, but the clinical signs associated with herpes virus and calicivirus infection can look very similar to flu in humans. Even though cats don’t have their own influenza virus, vaccinating them against herpes and calicivirus will help keep them healthy and limit the impact of upper respiratory viruses on their health.

Can my dog or cat catch the flu when I am under the weather?
Feeling sick? Thinking cuddling with your cat or dog will make you feel better? Wrong. Cats and dog can contract human flu. When you have the flu, quarantine yourself from all members of your family, including your pets.

If you must touch your pet while you are sick or prepare their food, be sure to wash your hands before doing so. Cover your coughs and sneezes to keep everyone else in the family healthy, including the pets.


This may also be found in the “Tales from the Pet Clinic” blog on

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