Please ensure Javascript is enabled for purposes of website accessibility

Canine Flu Outbreak Caused by New Strain

Rebekah Harrison//April 14, 2015//

Canine Flu Outbreak Caused by New Strain

Rebekah Harrison //April 14, 2015//

Listen to this article

According to laboratory scientists at Cornell University, the canine flu outbreak in Chicago and other parts of the Midwest affecting 1,000 dogs is caused by a different strain of virus than was earlier assumed. Therefore, vaccines could be ineffective.


Researchers at Cornell say results from additional testing indicate that the outbreak is being caused by a virus closely related to Asian strains of influenza A H3N2 viruses, currently in wide circulation in southern Chinese and South Korean dog populations since being identified in 2006.

There is no evidence that it can be transmitted to humans.

Testing of clinical samples from the outbreak conducted at The New York State Animal Diagnostic Laboratory at Cornell indicated that the virus was Influenza A. Researchers now believe a new strain is at fault. Subsequent testing, carried out with the assistance of the Wisconsin Veterinary Diagnostic Laboratory, identified the new subtype as H3N2.

It not known if the current vaccine will provide protection from the new strain.

“This is important information for all pet owners to know,” said Dr. Juliet Gladden, a board-certified specialist in emergency and critical care with BluePearl in Illinois. “While we don’t want to discourage people from vaccinating their pets, it may be more important to heed warnings to avoid places such as dog parks or grooming salons where the virus could be spread.”

According to the researchers, the outbreak had been attributed to the H3N8 virus but the new tests show that it is the H3N2 virus, which is typically found in southern Chinese and South Korean dog populations. Unlike the other strain, H3N2 may cause illness in cats.

Both strains cause high fever, loss of appetite, coughing, nasal discharge and lethargy. However, symptoms may be more severe in cases caused by the H3N2 virus.

“If you notice any of these symptoms, please call your primary care veterinarian or an emergency care hospital before taking any action,” said Gladden. “They may have suggestions for managing your case at home, which could help prevent the disease from spreading further.”