Mystery respiratory dog illness has pet owners concerned. Here’s what vets are saying.

Update: On Wednesday, Nov. 29, Pennsylvania’s Agriculture Department reported cases of the illness in Pennsylvania. It’s unclear how many cases there are since there is no official record. Read more here.

A respiratory illness deemed a “mystery illness” by veterinarians is impacting dogs across the country, causing symptoms like lethargy and sneezing. Just ahead of the holiday season, pet owners say they’re worried as some rethink boarding and gatherings.

“Oh, it’s definitely on my mind [while] living in the city, where people let their dogs say hi on walks, dog park interactions, and doggy day cares,” said South Philly-based Randi Figures Yavorsky who has two chihuahua mixes. “It’s very scary. … My dogs are up to date on their shots, including the flu shot, and I can’t imagine them getting sick and not having answers.”

Little is known about the origins of the illness, but experts say there are preventative measures that can be taken.

Here’s what we know.

The illness is considered a respiratory disease by experts and its symptoms can include loss of appetite and optical and nasal discharge. In some cases, it has led to pneumonia or hospitalizations.

And while much about the disease is still unknown, experts say they’ve been studying the virus for over a year.

Instances of the disease have been cropping up over the last few months, but cases have been increasing recently, especially in Oregon. The virus does not have a name yet.

Deborah Silverstein, a University of Pennsylvania School of Veterinary Medicine professor and section chief of emergency and critical care, said the illness is likely a resurgence of at least some of the organisms seen with canine infectious respiratory disease complex — the formal name for kennel cough.

Officials say 14 states have documented cases of the illness. No cases have been reported in Pennsylvania or New Jersey at this time.

States with cases include California, Colorado, Florida, Georgia, Idaho, Illinois, Indiana, Massachusetts, New Hampshire, Oregon, Rhode Island, Maryland, Washington and Vermont.

The American Veterinary Medical Association reported at least 200 cases in Oregon since August, but there is no official count of infections.

Last week, a University of Pennsylvania School of Veterinary Medicine spokesperson confirmed with The Inquirer that the school has not seen a marked increase of the mysterious illness or other respiratory illnesses at its hospital.

By Wednesday, the spokesperson said they’d received “a couple” of respiratory cases on campus. Still, Silverstein said respiratory colds are “quite common” and that the number of dogs impacted ebbs and flows in different areas throughout the year.

She added that clusters of sick dogs increased after the main COVID-19 pandemic wave because of factors including more people adopting dogs, a rise in boarding dogs, and an increased popularity in doggy daycare.

Several Philly-based vets have begun sending emails to clients to try and curb anxiety surrounding news about the illnesses.

“It is definitely respiratory disease ‘season’ right now, which makes things scarier when you see articles about an unknown emerging disease,” Companion Pet Hospital personnel out of Dickinson Narrows said in an email to pet owners. “Philadelphia was seeing an increase in respiratory cases with more severe outcomes in early 2023 ... While it is possible that we will see a return of this severe respiratory disease, we are not seeing it at this time. We are definitely seeing an increase in milder cases, however.”

Like any respiratory disease, the spread of the illness comes from close contact and sharing air with — even through barking — an infected dog. People also can transmit the germs from one dog to another.

For this reason, communal areas with multiple dogs and shared items, like water bowls, can increase the risk of a dog picking up the virus.

Arielle Harris is a board member with the South Philadelphia Association of Dog Owners (SPADO), a nonprofit that manages upkeep at the Columbus Square dog park.

She said the virus has been top of mind for her and she believes cases appearing in Pennsylvania is inevitable.

“I figure once news breaks of it being in Pennsylvania, we will release a general statement just urging people to exercise caution,” she said.

Harris said that while the park requires dogs to be registered with the ACCT and up to date on vaccinations already, there’s no way to verify a dog’s vaccination status upon entry since it is a volunteer effort. It’s all based on good faith.

“All SPADO can do is try our best to keep the park as clean as possible,” she said.

She added that the board cleans the park monthly and does not have access to running water during winter because the pipes are shut off to avoid freezing. In turn, dog owners are encouraged to bring their own water supply (though empty bowls are still available).

“We suggest caution rather than worry,” the Oregon Veterinary Medical Association said.

The organization added that periodic outbreaks of respiratory diseases are to be expected. This just happens to be the latest version.

Stephen Kochis, the chief medical officer for the Oregon Humane Society, told the New York Times he doesn’t want dog owners to panic because of the uptick in cases.

According to the New York Times, the virus itself isn’t usually fatal, and veterinarians have not reported an increase in deaths. Still, they’re cautioning dog owners to decrease contact with other dogs and monitor and treat symptoms to make sure it doesn’t escalate to a more dangerous secondary infection.

Silverstein with PennVet added, “Stay calm. There is no evidence at this time to cause major concern.”

Typically, respiratory illnesses, like kennel cough, last one to three weeks. In this case, experts say the mystery illness can linger or take a downward turn.

For that reason, vets say if a dog is showing symptoms, their owner should be proactive.

“Isolate them in the home, call your vet, get them seen,” David Needle, a senior veterinary pathologist who has been researching the virus for a year, told the New York Times.

Experts say the best things dog owners can do to try to avoid or minimize the impact of the mystery illness include: