Currently there are 2 different Influenza A viruses known to infect dogs. The H3N8 Virus which mutated from the equine flu virus has been a known cause of influenza in the dog since 2004 when it first showed up in Florida among the Racing Greyhound population. The second canine influenza virus moving around the country lately is the H3N2 strain which has only been in our country since 2015 and came from a mutated virus of a bird flu strain seen in China, South Korea and Thailand.
Neither of these viruses cause disease in humans. The H3N2 strain has been seen to cause disease, but no deaths in cat populations (shelters). Both viruses can cause a range of signs involving the respiratory tract lining in dogs: coughing, nasal discharge, in-appetence, lethargy, and sneezing. Some dogs do not show signs of the disease but can still spread it to other dogs. The illness can last for 10-21 days. Dogs with other underlying problems are most susceptible to complications and possible death. There have been no cat deaths and the canine death rate is around 3-5 %.
The virus is spread through the air (droplet infection) and through contact with objects that harbor the virus. The virus can live in the environment for 48 hours and 24 hours on clothes. It can live on human hands for 12 hours. It can take a dog 1-5 day to show signs of the H3N8 influenza virus and 2-8 days for the H3N2 virus to produce disease. About 20% of the dogs infected with a canine influenza virus will not show signs of illness, but can still infect others. Dogs can shed the virus for 3-4 weeks regardless if they are ill or not. The incubation period (before a pet becomes ill) is the time that the pet will shed the most virus.
There is a test to see if a pet has the influenza virus. This involves swabbing the nose and back of the throat. This test screens for several respiratory diseases so a proper and more complete diagnosis can be made. The test results take several days. Treatment for the presenting signs may be started prior to receiving the results.
Treatment is symptomatic and may involve cough suppressants and/or expectorants. An antibiotic may be prescribed if secondary bacterial infections are suspected. An antibiotic will not kill the influenza virus. Prevention is the key to help with any outbreaks. There is a vaccine that will help protect against both the H3N8 and H3N2 vi-ruses. This vaccine is given as an injection under the skin and needs boosting in 3 weeks.
Protection is not achieved until after the second shot. A yearly booster is needed. Protection is not 100%. We are recommending this vaccine for dogs that board or go to places populated with other dogs (dog parks, shows, expos, pet stores, and training facilities), or those that travel with their owners. If you are wondering if your pet is at risk and needs vaccination or to schedule an appointment, please call the Glacial Ridge Veterinary Clinic at 320-634-3558.