Steamboat Springs — A strain of canine influenza new to the United States has sickened more than 1,000 dogs mostly in the Chicago area and has caught the attention of veterinarians in Steamboat Springs.

The outbreak which began in early April was caused by a virus closely related to the influenza A H3N2 virus, a dog flu in wide circulation in southern China and South Korea but absent from the U.S. until now.

“We’re definitely concerned about it,” said Dr. John Rule, a veterinarian at Mt. Werner Veterinary Hospital. “But right now Colorado is not a problem.”

Rule said he receives regular email updates from the Colorado Veterinary Medical Association with reports of new cases, which have now been identified in at least 11 states, according to Cornell University’s Animal Health Diagnostic Center in Ithaca, New York.

An analysis of the virus by the Centers for Disease Control and Prevention concluded it could not be transmitted to humans, though it can spread to cats.

The H3N2 outbreak was originally thought to be the H3N8 canine influenza virus, which was first identified in the U.S. in 2004, according to researchers at Cornell. It’s unknown if the current vaccine available for the H3N8 strain would offer dogs any protection against the new strain.

Symptoms of either flu include high fever, loss of appetite, coughing, nasal discharge and lethargy.

Although its unlikely at this point for the H3N2 flu strain to pop up in Northwest Colorado, viruses such as canine influenza are known to mutate and be very contagious, according to Dr. Michael Gotchey, a veterinarian at Steamboat Veterinary Hospital.

“Epidemics happen quick, and just like the flu in humans, you may not see symptoms for a few days, but it’s still infectious,” Gotchey said.

Gotchey said in Chicago, dogs are often grouped with other dogs at animal day care facilities, which may have played a role in the rapid outbreak there.

Once a group of dogs catches the virus, the sickness runs its course relatively quickly, he said.

In Steamboat, dogs typically mingle with the same groups of dogs, and its rare for many out-of-area dogs to group together with Steamboat dogs, especially during mud season, reducing the risk of an infected dog spreading the flu here, Gotchey said.

“We probably won’t see it,” he said. “Our dogs are pretty healthy, and we don’t have a lot of dogs congregating in small areas. Our dogs are out running around.”

Gotchey said there are occasional outbreaks of kennel cough in Steamboat, but they usually run their course through dog groups quickly.

To reach Teresa Ristow, call 970-871-4206, email tristow@SteamboatToday.com or follow her on Twitter @TeresaRistow