Poolesville Veterinary Clinic

Monday to Friday 7:30am–7:00pm
Saturday 9:00am–2:00pm
19621 Fisher Ave. • Poolesville, MD 20837 • 301.972.7705

Canine Influenza

What is canine influenza (Dog flu)?

A highly contagious respiratory disease in dogs caused by A H3N8 influenza virus (this is not a human influenza virus).  The virus is a mutation of the equine (horse) influenza virus.  Humans cannot contract either of these viruses.  Since influenza viruses have a potential to mutate (change) its infectious potential the CDC is monitoring the H3N8 virus.

How is it spread (In Dogs)?

The virus is transmitted (spread) from actively infected dogs by direct contact, aerosolized (air carried) secretions (sneeze, drool), by contact with contaminated objects and by people moving between infected and uninfected dogs or their infected environment.

When was it first discovered in dogs?

The first report of flu like disease signs affecting dogs was identified in Florida Grey Hound populations in 2004.  Outbreaks have been found in Virginia and Delaware and most recently in Lower Montgomery County, Maryland. Scientists believe that the Equine (horse) H3N8 virus “jumped” species and mutated (adapted) in the dog’s respiratory tract.  In 2005 it was considered to have become a new dog-specific line H3N8 virus.

What are the Signs and how serious can this infection be in your dog?

The first signs of the H3N8 influenza virus are usually increasingly strong cough (dry to productive), runny nose progressing to thick greenish/yellow discharge and a high fever 104 to 105 degrees F (normal dog temperature is 101 to 102 degrees F).

The mortality rate (number of dogs that die) is very small.  The range of effect is from asymptomatic (virus present but no signs) to full pneumonia and death.  All dogs are susceptible but about 80% will have the mild to moderate form and recover after about 10-14 days with supportive care.  The very young and very old are at greatest risk for severe life threatening disease.

Is there a test for the H3N8 canine influenza virus?

YES. Both a direct test from the secretions (nasal fluid) to find the active virus or two blood tests taken three weeks apart to look for antibodies are available from your veterinarian.

How is canine influenza treated?

Treatment is mainly by supportive care.  This can include medication to reduce the fever and discharge and fluids to support the respiratory and cardiovascular (heart and blood) system.  Supportive care is continued until the dog can mount an immune response.  In some cases a secondary bacterial infection occurs that can require antibiotics.  Antiviral agents can have severe side effects and should only be given under the authority of a trained veterinarian.

Is there a vaccine available now? YES!

Antibody protection is produced from two vaccines given under the skin, 3 weeks apart. Puppies six weeks of age or older are safe to get the vaccination.  The vaccine is safe for all older dogs.  The vaccine is made from a chemically inactivated (killed) H3N8 virus cell strain.  It is impossible for your dog to contract the canine flu virus from the vaccine. Dogs that have been previously immunized should get an annual re-booster.  Vaccines against the H3N8 canine influenza virus should be given to any dog that is visiting areas where infection as been found, public pet runs, grooming and day care facilities, public parks or training operations.  Consult your veterinarian if you think your dog may be at risk and could benefit from vaccination.