A number of cats in a northwest Indiana animal shelter have tested positive for the H3N2 canine influenza virus.
When a group of cats at the shelter started showing uncommon symptoms of respiratory disease, shelter workers became suspicious that the symptoms might indicate an outbreak. Veterinary researchers from the University of Wisconsin School of Veterinary Medicine tested the cats and confirmed they were suffering from canine influenza.
Reported cases of canine influenza-stricken cats in South Korea suggested that the virus could jump from dogs to cats, but the disease did not appear in the U.S. until 2015. When it did, a large number of dogs in the Midwest fell ill, but only one cat tested positive for the virus. That cat was never re-tested because the positive result was not confirmed until after the cat had recovered.
The H3N2 outbreak among the cats at the Indiana shelter suggests that last year's single feline case was not the end of the story. It seems the virus can in fact replicate and spread among cat populations. According to veterinary virologist Kathy Toohey-Kurth:
"Sequential sampling of these individual cats have shown repeated positives and an increase in viral loads over time."
Unfortunately, the outbreak has also infected some of the shelter's dogs.
Research has revealed that the genetic makeup of the feline version of canine influenza is identical to the H3N2 virus that strikes dogs. Clinical symptoms in cats include upper respiratory symptoms (congestion and a runny nose), general malaise, lip smacking, and salivation. The virus has not resulted in any fatalities, and with supportive care, cats with the virus usually recover quickly.
In dogs, symptoms of canine influenza include a persistent cough, fever, and a runny nose, though in some cases, infected dogs display no symptoms. Most dogs stricken with the illness also recover with supportive care, although the virus has been fatal in some cases. There is an H3N2 vaccine now available for dogs, but no such vaccine exists for cats.
The University of Wisconsin's veterinary specialists are working with the Indiana shelter to contain and manage the outbreak. All infected dogs and cats have been quarantined, and none have left the shelter. With any luck, they'll all be back on their feet and into their forever homes in no time.