A baffling respiratory illness is sweeping across the United States, affecting dogs of various breeds and ages. Characterized by symptoms such as a persistent cough, runny eyes, and sneezing, the illness has become a source of worry for dog owners, particularly as it has led to fatalities in some cases.

“It seems to happen very, very quickly — to go from this cough that’s just won’t go away … and then all of a sudden they develop this pneumonia,” Dr. Lindsey Ganzer, veterinarian and CEO at North Springs Veterinary Referral Center in Colorado Springs, told TODAY.com.

The hunt for the culprit: canine microbiome renders clues

Scientists at the University of New Hampshire‘s Veterinary Diagnosis Laboratory and the Hubbard Center for Genome Studies have identified a potential culprit: a previously unknown bacterium. This pathogen, described by Dr. David Needle as “a funky bacterium,” is unique in both size and genetic makeup, challenging conventional detection methods.

This revelation emerged from extensive genetic sequencing of samples from initially 30 dogs in New Hampshire, later expanded to include 40 more from Rhode Island and Massachusetts. The analysis revealed a bacterium that is smaller than usual, both physically and genomically, suggesting a complex interplay with the canine immune system.

The newfound bacterium’s origins can likely be traced back to the dog microbiome, a complex ecosystem of microorganisms residing in and on canine bodies. Virtually all mammals have such a gut flora, including humans. The human gut microbiome is made up of hundreds to thousands of species of bacteria and archaea. Typically harmless, these microbes are essential for various bodily functions, including digestion. But sometimes, harmful bacteria may mutate. The pathogen’s evolution from such benign origins highlights the dynamic nature of microbial ecosystems.

The spread of this respiratory illness is not limited to a single region. States including Oregon, Colorado, California, Indiana, Illinois, and several others have reported cases. The Oregon Agriculture Department alone has logged over 200 cases since August. The wide range of symptoms, mirroring those of other respiratory diseases like canine influenza and Bordetella (kennel cough), complicates the diagnostic process, clouding the true extent of the outbreak.

Balancing caution and calm

While the veterinary community as a whole is concerned, they don’t want to cause panic among dog owners. The number of dogs who have turned up to clinics with symptoms of this new respiratory disease is very small compared to the overall population in the affected states.

Finding the right antibiotic to cure this illness first starts with cultivating the pathogen in a petri dish. However, Dr. Needle and his team were not able to grow the bacterium in laboratory conditions. Despite this, the structure of the bacterium offers some hints. The antibiotic doxycycline could work as a potential treatment, though more research is needed to confirm its efficacy.

In fact, more research in general is urgently needed. It’s not clear whether the illness is bacterial, although the University of New Hampshire researchers want to soon publish their findings. However, it wouldn’t be surprising to learn that other researchers find the pathogen is a virus. It is still too early to tell for sure.

As the holiday season approaches, bringing with it increased travel and gatherings, veterinarians urge caution for dog owners. They recommend avoiding places with high dog populations, such as kennels and dog parks, to reduce infection risk. Vaccination against known respiratory diseases is also advised.