Dog Respiratory Illness Maps Show Its Spread to 16 States

Dogs are falling sick with a mystery illness across the United States, with cases being recorded in at least 16 states, according to the latest figures from Louisiana State University's School of Veterinary Medicine.

Cases of Atypical Canine Infectious Respiratory Disease Complex (aCIRDC), as it has been dubbed until the cause of the illness is established, have appeared in Pennsylvania and Nevada most recently, after being found among dogs in 14 states in late November. It was previously documented in 11 states.

Other states with confirmed cases are: California, Colorado, Florida, Georgia, Idaho, Illinois, Indiana, Maryland, Massachusetts, New Hampshire, Oregon, Rhode Island, Vermont and Washington state.

Mike Stepien, a spokesperson for the U.S. Department of Agriculture's Animal and Plant Health Inspection Service, told Newsweek it "is currently working with multiple state animal health officials and diagnostic laboratories regarding reports of respiratory illness in dogs that, in rare cases, has progressed rapidly to death," who have "not yet definitively identified the cause of illness."

The illness was first recognized in Oregon earlier in the year, where the Oregon Veterinary Medical Association said it had received 200 reports, with cases appearing to be focused around the Portland area.

Though local dog medics previously told Newsweek there seemed to be little evidence of a widespread outbreak, several holiday dog events have been canceled over fears of the spread of the disease, while health officials have urged owners to limit dogs socializing.

The disease has since cropped up in states across the West Coast, before turning up in states on the East Coast and Great Lakes regions.

Canines that come down with the illness are said to develop symptoms including a cough, fever and lethargy. Some can contract pneumonia and, in some cases, it can lead to death.

Experts at LSU's School of Veterinary Medicine said that treatment was currently limited to addressing symptoms due to the unknown nature of the cause of the illness, and urged owners planning to travel for the holidays to ensure their dog is properly vaccinated and "take special care" when considering whether to take it to another state.

They added that "there is currently no evidence of zoonotic potential (no evidence it can be spread from animals to people)."

The University of New Hampshire's Veterinary Diagnostic Laboratory has said that it may have identified a bacterium that may be responsible for the sickness, based on genetic sequencing of 30 dogs that were infected in the state in 2022 and a further 40 from Rhode Island and Massachusetts this year.

David Needle, chief pathologist at the diagnostics lab, described the microbe that they had isolated as "a weird bacterium" to NBC News, as it was smaller than normal bacteria that did not have a cell wall.

His team have since received samples from Oregon, and are due to receive more from Colorado and Illinois, in a bid to isolate the common cause of the illness, LSU said.

Needle previously told Newsweek that the most likely hypothesis was that the illness was caused by a member of "the normal community of bacteria and other microorganisms that live in the respiratory tract," but had developed a "virulence-associate[d] gene/trait."

Stepien said the Animal and Plant Health Inspection Service "understands the concerns pet owners have regarding the increase of dog respiratory illness," but these cases were not due to an animal disease it regulates and so it "does not have systematic surveillance information such as numbers of cases throughout the country or when these cases started."

He added it would "continue supporting states with testing when needed, but our support role is limited to testing and collaborating with partners."

Update 12/14/23, 3:00 a.m. ET: This article was updated to include comment from a spokesperson for the U.S. Department of Agriculture's Animal and Plant Health Inspection Service.