Can dog owners catch the mysterious dog respiratory illness? Experts shed knowledge.

Veterinary experts are puzzled about the pathogen that has caused respiratory illness in hundreds of dogs across the U.S., but there's one matter they tend to agree on. They believe the disease is not likely a risk to human health.

In the meantime, experts said, it's wise to wash your hands after you've spent time with dogs.

More than a dozen states, stretching from Oregon to Florida, have reported cases of dogs sick with prolonged pneumonia and inflamed trachea who aren't responding to medicine. It’s unclear what’s triggering the strange illness, which has resulted in serious illness and, in rare cases, death.

“We really need to be able to separate the wheat from the chaff,” said Dr. Kurt Williams, director of the Oregon Veterinary Diagnostic Laboratory, at Oregon State University’s Carlson College of Medicine, which is working with the state Department of Agriculture to help study more than 200 cases of the illness since September.

See the maps, signs: What is the mysterious respiratory illness affecting dogs across the US? Graphics explain

Williams told USA TODAY there is no evidence humans are contracting the illness, nor is there evidence that other pets are. Dr. David Needle, a senior veterinary pathologist at the University of New Hampshire’s Veterinary Diagnostic Laboratory, said the pathogen is “host adapted,” meaning it’s more likely to stick with the organism it has already infected, rather than jump to another species.

In a statement to USA TODAY, Dr. Colin Basler, deputy director of the Centers for Disease Control and Prevention's One Health Office, which is tasked with preventing the spread of disease from animals to humans, said there is no evidence that the dog illness can infect people.

"There is no known risk to human health linked to the respiratory illness in dogs," he said. "The cause of illness is still being investigated by veterinary medical and animal health partners."

Map of illness: Mysterious and fatal dog respiratory illness now reported in 14 states: See the map.

Mysterious respiratory illness is spreading amongst dogs
Mysterious respiratory illness is spreading amongst dogs

The American Veterinary Medical Association has made similar findings, but Dr. Rena Carlson, president of the association, stopped short of calling it impossible that people could catch the disease.

“In general, the risk of people getting sick from dogs with canine infectious respiratory disease is extremely low,” Carlson said in a statement on Wednesday. “However, because we don’t know yet exactly what agent or agents ... are causing the current outbreak, it’s a good idea to thoroughly wash your hands after handling your or other dogs.”

This early in the outbreak, far more is unknown than known. Scientists disagree about what kind of pathogen is causing the disease among dogs. The disease might be new or it may have been around for years.

Researchers at Colorado State University said clinical findings indicate the disease could be caused by a virus. Needle, of the University of New Hampshire, said it's a bacterium. Even if veterinarians identify bacteria or virus in a sick dog, it doesn’t mean the pathogen they found is what is causing the disease, said Dr. Jason Stull, an assistant professor of veterinary preventive medicine at the Ohio State University, in an email.

‘Treating both ends of the leash:' How a new Pittsburgh clinic treats humans, pets

In Oregon, Williams said he's being cautious about pinpointing a cause while he continues to rule out pathogens. Studies from biopsies of dogs’ lung tissue can provide a better understanding of possible causes of the disease, he said.

While so many questions remain unanswered, he urged pet owners to remain patient and consult their veterinarians if they have concerns.

“These pathogens are wily little beasts,” he said. “And they’re trying to survive like the rest of us.”

If your pet is sick, Carlson, from the veterinary association, said, you should watch for signs of worsening coughing accompanied by eye or nasal discharge and sneezing, especially if your dog stops eating, has trouble breathing, is coughing continually or is very lethargic. She also noted owners should make sure dos stay updated on their vaccines.

Saman Shafiq contributed to this report.

Eduardo Cuevas covers health and breaking news for USA TODAY. He can be reached at

This article originally appeared on USA TODAY: Dog respiratory illness: Can humans catch it? Here's what we know.