From January, through April, doggie docs have feared this moment.
A violent strain of Asiatic dog flu sickened more than than 1,000 dogs in and around Chicago -- and killed six.
And then, strangely, it stalled.
The rate of new infections involving canine influenza virus (CIV) strain H3N2 even slowed.
It was a short-lived victory.
Suddenly, the H3N2, was on the move, reports Fox and NJ.com., showing up in New York State, Jersey, and Mass.
More than 5,000 dogs have caught the virus, which is generally treatable but comes with a persistent cough, runny nose, lack of appetite and fever.
It is not known how the H3N2 strain was introduced into Chicago but it could have been a dog from Asia who was a carrier and did not have active symptoms, said
Keith Poulsen, diagnostic and case outreach coordinator with the Wisconsin Veterinary Diagnostic Laboratory.
Cook County officials have reported 1,137 cases in the Chicago area, with six deaths. While an exact figure for the Midwest is not available, Poulsen believes it is less than 5,000 cases.
The virus can also affect cats, but not humans, Reuters reports.
About 5 percent or fewer affected dogs die from the more familiar H3N8 strain - mostly older dogs or puppies. Fatalities from the new strain also are expected to be less than 10 percent of animals affected, Poulsen said.
"Contact your veterinarian with questions," he said.