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.

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.