DELAND, FLORIDA — A highly contagious form of canine influenza is spreading in the U.S. It has already killed two dogs in North Carolina and 300 more have been infected in the country.

One of the dogs that were killed by the H3N2 virus was associated with a dog show in Florida. The virus is believed to have originated from two dog shows, one in Perry, Georgia and the other in Deland, Florida, according to WCTV quoting the Florida Department of Agriculture. The H3N2 strain of canine flu was first recorded in Chicago in 2015.

Canine flu is spread by coughing, barking or sneezing. The flu can easily be spread in places like dog shows, dog parks or pet stores. Kennels, bowls and other pet objects can also spread the disease as the virus remains viable for up to 48 hours on the surfaces of such objects.

Almost all dogs are susceptible to canine flu infection. Dogs infected with the virus may not show symptoms until up to four days after infection. Isolation is the only way to contain the virus from spreading.

There is only one approved vaccine that can protect dogs against canine influenza A H3N8, but it is unknown whether it can shield dogs against the H3N2 virus.