WINDSOR, ONT.—Health officials say five more dogs have tested positive for a strain of canine influenza in southwestern Ontario, bringing the total number of infected up to seven in what they’re calling the virus’s first known incursion into the country.

The Windsor-Essex County Health Unit says the two dogs that initially tested positive for H3N2 canine flu were brought to Canada from South Korea through the United States late last month.

It says the five dogs that most recently tested positive for the virus were in “close contact” with the first two.

Officials say the affected dogs — and others that were in contact with them — are being confined by their owners.

Health officials say the H3N2 canine influenza virus is highly transmissible between dogs and has become widespread in parts of Asia and caused outbreaks in some U.S. locations, particularly in shelters.

They say there is no known human risk from the virus, but note the risk that it might mix with human seasonal influenza viruses is “a potential concern.”