Published by: Ingrid King. Last Updated on: June 30, 2023 by Crystal Uys


The H3N2 virus, which was responsible for infecting a large number of dogs in the Midwest last year, appears to be transmittable to cats as well. The Shelter Medicine Program at the University of Wisconsin has confirmed that the virus has infected a group of cats in the region.

“Suspicions of an outbreak in the cats were initially raised when a group of them displayed unusual signs of respiratory disease,” says clinical assistant professor and director of the Shelter Medicine program, Sandra Newbury. “While this first confirmed report of multiple cats testing positive for canine influenza in the U.S. shows the virus can affect cats, we hope that infections and illness in felines will continue to be quite rare.”

It was already known that the virus could infect cats when some cases were reported in South Korea. Last year, one cat tested positive in the US. All of this suggests that the virus can replicate and spread from cat to cat.

Preliminary work to study the genetic signature of the virus that infected the shelter cats shows it to be identical to the H3N2 virus that infects dogs. Researchers and the UW Shelter Medicine team are working closely with the animal shelter to manage the influenza outbreak. “At this time, all of the infected cats have been quarantined, and no infected cats or dogs have left this shelter,” Newbury says. “We will continue to watch carefully for instances of the disease.”

Girl and woman owners holding cats in shelter to adopt
Image Credit: BearFotos, Shutterstock

What does this mean for your cat?

This new information shows that when it comes to flu viruses, nothing stays constant. Viruses mutate, and new viruses appear. An H3N2 vaccine is currently available for dogs, but no vaccine is available for cats.

Symptoms in the infected cats have been similar to those seen in dogs: runny nose, congestion, and general malaise, as well as lip smacking and excessive salivation. Symptoms have resolved quickly and so far, the virus has not been fatal in cats.

It’s impossible to know whether this outbreak is an isolated incident, or whether it’s a harbinger of things to come. Only time will tell. If your cat shows flu-like symptoms, contact your veterinarian.

For more information, please visit the University of Wisconsin School of Veterinary Medicine website.

Featured Image Credit: ira008, Shutterstock

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