Mysterious respiratory illness affecting dogs in at least a dozen states

(CNN) — An infectious respiratory disease among dogs that continues to baffle veterinarians has now been reported in at least a dozen US states, from Washington, Oregon and California to New Hampshire, Florida and Pennsylvania. Idaho may be included in this list as well.

David B. Needle, a pathologist at the New Hampshire Veterinary Diagnostic Laboratory and clinical associate professor at the University of New Hampshire, and a team of researchers have been unable to identify it as any known canine respiratory disease.

“This early metagenomic work did not reveal any RNA or DNA virus of concern, and no typical fungal or bacterial respiratory pathogens were identified,” the researchers wrote.

Since the middle of August, the American Veterinary Medical Association said vets in Oregon have reported over 200 cases.

The mysterious illness was described as an “atypical canine infectious respiratory disease,” by the Oregon Department of Agriculture and symptoms include coughing, sneezing, eye or nose discharge and lethargy.

Melissa Justice, a veterinarian at the Indiana State Board of Animal Health, told CNN most of the cases reported to her agency appear to be similar to kennel cough, but it doesn’t respond to normal medication and the cough lasts longer than the normal seven to 10 days.

“Affected dogs may begin to show signs of lethargy, fever, decreased appetite, productive cough, nasal and/or ocular discharge, respiratory distress, or pneumonia,” Justice said.

The federal government is also getting involved. A spokesperson for the US Department of Agriculture Animal and Plant Health Inspection Service told CNN it is working with local agencies and diagnostic laboratories to identify the disease.

Where have cases been reported?

Pennsylvania may be the latest state to have dogs possibly coming down with the mystery illness.

John Donges of the School of Veterinary Medicine at the University of Pennsylvania told CNN, “We have only just received our first cases over the weekend.”

In Colorado, veterinarians are seeing a lot of cases in high-volume areas such as boarding facilities, doggie day cares and dog parks.

“Clinical findings and tests completed to date suggest that most dogs with the unusual syndrome have a virus that primarily targets the respiratory system, leading to secondary bacterial infection and pneumonia in affected dogs,” said an article published by the Colorado State University College of Veterinary Medicine and Biomedical Sciences.

“We have seen around 35 cases at my hospital alone, four of which have either passed away or been euthanized due to severity of the pneumonia. We are unsure at this time if this is viral or bacterial in origin,” Lindsey L. Ganzer, the CEO of North Springs Veterinary Referral Center in Colorado Springs, told CNN.

In Massachusetts, the Department of Agricultural Resources said it is working with neighboring states “to better understand the factors at play” and kennel operators should be requiring vaccination to prevent future outbreaks.

Veterinarians in California have seen the disease, too, with the Los Angeles County Department of Public Health’s Veterinary Public Health Program receiving 10 case reports from veterinarians since November 16.

In Washington, the state’s Animal Disease Diagnostic Laboratory has also reported an increase in sick dogs.

“There has been an uptick in the numbers of dogs with respiratory disease, (coughing, lethargy, fever) and the signs have been persisting longer than a few days,” Kevin Snekvik, the lab’s executive director and a professor at the Washington State University College of Veterinary Medicine, told CNN.

The Rhode Island Department of Environmental Management said because a common cause of the illness reported in other states hasn’t been determined, it is hard to say if the disease has reached the state, but acknowledged the department “is aware of a small number of dogs in the state that died or were euthanized after experiencing similar signs. Unfortunately, these dogs weren’t subjected to a postmortem examination, so the cause of their illness was not determined.”

Idaho State Veterinarian Scott Leibsle also said there was no way to be sure, but “since the recent media reports have come about, several vets in Idaho have reached out to ISDA (Idaho State Department of Agriculture) with reports that they had seen multiple cases of an aggressive respiratory disease that is minimally or non-responsive to treatment, over the course of the summer (June/July/Aug).” But those veterinarians said more recent cases of respiratory disease in dogs seem to be more routine, according to Leibsle.

Vermont State Veterinarian Kristin Haas said New England has been seeing cases of this since at least early summer 2022. Some cases have been fatal, while others have not gone beyond the equivalent of a “common cold” type illness, Haas said.

The University of Florida College of Veterinary Medicine recently wrote that the lack of a centralized reporting system for canine diseases means it’s not even possible to confirm a spike in a known disease like kennel cough or if there is a new emerging pathogen.

“At this time, we recommend being especially vigilant to identify and segregate dogs with respiratory signs,” the college said.

What can dog owners do?

Dog owners can help keep their pets healthy by making sure they’re up-to-date on all vaccines, such as those for canine influenza, Bordetella and parainfluenza, the Oregon Veterinary Medical Association said.

Other tips include:

• Reducing contact with large numbers of unknown dogs. Just like with other respiratory pathogens, the more contacts your dog has, the greater the risk of encountering a dog that’s infectious.
• Reducing contact with sick dogs. This can be harder to determine but if a dog looks sick (coughing, runny nose, runny eyes), keep your dog away from it.
• Keep sick dogs at home and seek veterinary care.
• Avoid communal water bowls shared by multiple dogs.