(CBS) — As dog owners consider boarding their pets for the upcoming holidays, a new vaccine is now available to protect against the dog flu that attacked Chicago this spring.

WBBM’s Nancy Harty reports.

There was a vaccine this past spring, when thousands of dogs came down with the virus, but it was for the wrong strain. The new shot, released this week, covers the H3N2 strain.

Dr. Natalie Marks of Blum Animal Hospital says her office has seen nine positive cases of the canine flu in the past two weeks. The number of cases could increase as owners board their pets for the holidays.

“We really hope people will take this vaccine seriously,” she says.

The vaccine requires two doses and has a three-week waiting period between each. Marks says it would be a good idea for dog owners to start right away.