Printable Handout Canine Influenza 10/2021

What is dog flu?

Canine Influenza (CIV or dog flu) is a highly contagious, viral, respiratory disease of dogs.  There have been only 2 strains of canine influenza in the United States – H3N2 and H3N8.  The canine influenza virus has shown no tendency to mutate each year as does the human influenza virus.  Dog Flu is different from “kennel cough” but can be hard to differentiate without testing.  It is possible to have both “kennel cough” and dog flu at the same time.

Canine Influenza tends to occur as “outbreaks” in more metropolitan areas. These outbreaks usually start in some sort of kennel or shelter situation and then spread to the general population.  Disease is spread rapidly during an outbreak and then within a month or 2 the situation dies down and the disease tends go away completely from that area.

There will be many rumors of outbreaks of dog flu that have not been confirmed.  This occurs when dogs are showing respiratory signs, but tests for canine influenza are not being performed.  Without the testing no one can know if these “outbreaks” are really dog flu, or are simply a form the more benign “kennel cough.”

How is dog flu transmitted?

Canine Influenza is mainly transmitted via aerosolization – in the breath and respiratory secretions of dogs shedding the virus.  Dogs housed together in a closed environment or dogs in close contact with one another can be exposed to the virus if one of the dogs is shedding.  Most cases are transmitted in boarding facilities or doggy-day-care facilities. 

The virus lives up to 2 days on surfaces outside of dogs, but is very easy to kill with most disinfectants.  A person could get the virus on their clothes or hands and potentially transmit it to another dog.  People and cats do not get canine influenza, although rare cases of cats testing positive for the virus have occurred.


How serious is dog flu?  What are the symptoms?

For most dogs, canine influenza will be very much like the flu in people – a bothersome and uncomfortable disease that will pass in about a week.  The main signs are respiratory:  cough, runny nose (clear or thick), sneezing, fever and increased breathing rate or effort.  Some dogs will loose appetite and become lethargic.  Some may have diarrhea.  Signs usually begin 2-4 days after exposure.

In some cases, as with people, influenza will lead to pneumonia or other severe respiratory infections.  These dogs can become severely ill and some can die.  Most severe cases will occur in dogs that are older, have pre-existing diseases or are immune-compromised in some way.

What do I do if I think my dog has the flu?

Always seek veterinary care as early as possible.  This disease is easiest to treat in the early stages and testing can only be done in the first 5 days of infection.  If your dog is not severely ill you will likely be asked to care for your dog at home so other patients are not exposed.  Antibiotics may be prescribed if a secondary infection is suspected, but dog flu is a viral disease and viruses are not killed by antibiotics.  

Any dog showing respiratory signs should be isolated from all other dogs immediately.  Do not go to day care or training classes.  Do not let your dog be within 20 feet of other dogs while out for walks.  Dogs that have been exposed can shed the virus for up to 28 days, so you need to isolate for a full month!

How do I prevent dog flu?

Fortunately, we have excellent vaccines!  Fully vaccinated dogs that are exposed can still contract and shed the virus, but they will generally get an extremely mild and often unnoticeable form of the disease.  Vaccination starts as 2 shots about 3 weeks apart and then requires yearly boosters to stay effective.

If you know there is dog flu in your area, avoid highly social situations where your dog may be exposed to a dog that is shedding virus.  Remember that healthy appearing dogs can still shed the virus!  During an outbreak avoid boarding, day care, interactive dog classes, dog parks and places like grooming facilities that require you to leave your dog in the same area as other dogs for several hours.

Always be sure to avoid communal water bowls – moisture allows viruses and bacteria to live longer.  Wash all toys and training items that have been used by other dogs before allowing your dog to be exposed to them.  Bring your own toys and lures to training classes.  Be sure to wash your hands after interacting with other dogs, particularly if there is an outbreak occurring in your area.

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