Dog flu sickens 1,300 dogs across Illinois, Indiana, Ohio, Wisconsin

CHICAGO (WLS) -- A dog flu outbreak has now spread to four states and is hitting the Chicago area hardest.

Thirteen hundred dogs in Illinois, Indiana, Ohio and Wisconsin have fallen ill. At least six have died.

Experts have tracked the virus to a rare strain of bird flu from Asia. It's not covered by the current vaccine.

Still, vets say you should have your dog immunized. They also urge pet owners to prevent their dogs from going nose-to-nose with other dogs to keep the virus from spreading.