At least 1,100 Chicago-area dogs have come down with a highly contagious strain of canine flu — and six have died — in what researchers said is a strain of the virus never seen before in the United States.
The current outbreak, the largest and longest-lasting in the region, is caused by a strain closely related to the Asian strains of the flu virus, laboratory scientists at Cornell University and the University of Wisconsin said in a statement this week.
Additional testing revealed the strain is closely related to the A H3N2 viruses, seen in dog populations in southern China and South Korea. The outbreak was initially believed to be caused by the H3N3 strain on the virus, identified in the U.S. in 2004, according to the statement released Sunday. Scientists said there was no evidence that H3N3 can be transmitted to humans.
"This virus has only been seen in Korea and China and our cases in Chicago are the first of its kind on our soil," Kimberly Cerny, the practice manager at Blum Animal Hospital in Chicago’s Lakeview neighborhood, said in a statement to NBC Chicago.
Veterinarians began reporting cases of Canine Infectious Respiratory Disease, or CIRD, in January, said Cook County spokesman Frank Shuftan. There may be more cases than have been reported, Shuftan said.
"A lot of vets are so busy now they're having a difficult time even calling our office," Shuftan said.
Veterinarians told NBC Chicago the current outbreak is a more severe strain of he virus, allowing dogs to develop the disease faster.
Symptoms of CIRD include persistent and lingering cough, lethargic behavior, poor appetite and a fever, said Dr. Donna Alexander, administrator of the Cook County Department of Animal & Rabies Control.
Humans cannot get dog flu, but they can spread it, so Alexander recommended thorough hand-washing after touching or petting a dog.
She said that until incidents of the outbreak slowed down, dog owners should avoid pet-friendly areas like dog parks, avoid group dog training activities and, if possible, not board their pets.
The outbreak has resulted in some pet boarders closing temporarily, including PetSmart, which closed three facilities in the Chicago area. Two reopened after a thorough cleaning and inspection, but one remains closed, along with three "doggie daycamp" operations, according to a spokeswoman.
"We want to do what’s right for our pets and our pet parents, and these closures are in the best interest of our community,” said Gregg Scanlon, senior vice president of store operations and services for PetSmart.
- Chicago-Area Dog Flu Outbreak Caused by Strain Never Before Seen in U.S.
- Officials: Dog Flu Outbreak Could Last Weeks, 5 Fatalities Reported