Over the past few weeks, there have been increasing reports of a new canine influenza outbreak in the Chicago area. This influenza outbreak afflicting more than 1000 dogs in Chicago and the Midwest, is caused by a different strain of the virus than previous United States outbreaks.
Dr. Edward Dubovi at Cornell University speculates that dogs rescued from meat markets in Asia may be responsible for bringing the new strain (H3N2) of the virus to the United States. This is in contrast to the previous outbreak in Montgomery County, Maryland in August of 2013, which was caused by the canine influenza virus strain H3N8. That local outbreak resulted in 22 confirmed cases and several confirmed deaths. The outbreak was contained and there have been no confirmed cases in our area since then.
The following are facts that dog owners need to be aware of:
- The influenza virus does not affect people
- Dogs at risk are dogs that go to day care, boarding facilities, grooming facilities, dog parks, or dogs going out into the community interacting with other dogs.
- Vaccination against kennel cough (Bordetella) will not prevent dogs from contracting the influenza virus but will prevent or lessen the severity of kennel cough.
- The current canine influenza vaccine is for a different strain (H3N8) and may not protect against the new strain (H3N2) of the virus.
- This strain of canine influenza can cause infection and respiratory illness in cats according to Cornell University but there have been no reports of feline illness in the Chicago area.
Canine influenza causes an acute respiratory infection and is a highly contagious virus. Mild cases mimic kennel cough- but the cough persists for 10-21 days despite treatment. Most dogs have a soft, moist cough, while others have a dry cough. Many dogs will have a nasal discharge and a low grade fever. The more severe cases will present with clinical signs of pneumonia, such as a high fever (104 – 106F) and increased respiratory effort.
The incubation period is typically 2-5 days after exposure before clinical signs appear. Infected dogs may shed virus for seven to ten days from the initial day of clinical signs. Many infected dogs will not display clinical signs and become silent shedders and spreaders of the infection.
Confirmation of the diagnosis requires polymerase chain reaction (PCR) testing at one of two major national laboratories.
Because the source of this new strain of the canine influenza virus is thought to originate in rescued dogs from Asia, it is possible that these dogs could be brought into multiple major cities in the United States. The extent of the exposure is not known at this time.
We recommend using caution if you plan on travelling to the Midwest with your dog. While it is unknown if there is cross protection between the new strain and the old strain of the virus, you may want to consider vaccination or boostering your dog if previously vaccinated with the currently available canine influenza vaccine.
Please call your veterinarian should you have any questions or concerns.
For additional information regarding this outbreak, we have included some informative links below.
More information about the source of the new strain:
The HSUS and Humane Society International (HSI) are aggressively fundraising and importing dogs from Korea away from the meat trade.