Across the country, pet dogs are falling sick with a flu-like illness, but scientists don’t yet know what’s causing it.
Dogs across the U.S. are getting sick with an unexplained respiratory illness.
As of Monday (Nov. 27), at least 14 states, including Oregon, New Hampshire, Colorado and Massachusetts, have reported cases of pet dogs of different breeds developing symptoms including cough, runny nose, lethargy and a loss of appetite. In Oregon, for example, more than 200 cases have been reported since mid-August. However, the first cases of the outbreak are believed to have been reported in New Hampshire as early as last year, an expert told Live Science.
The mystery illness’ symptoms resemble those of common respiratory diseases that affect dogs, such as kennel cough and canine influenza. However, the infection appears to last longer than those diseases typically do and seems resistant to treatment with antibiotics, vets say.
What are the symptoms of the new dog illness?
The unexplained dog disease is similar to common respiratory illnesses that affect canines. It typically starts with a cough that moves on to a fever, sneezing, a runny nose and watery eyes. However, not all the affected dogs have shown the same combination of symptoms.
Normally, dogs recover from respiratory illnesses fairly easily, either on their own or with the help of antibiotics in the case of bacterial infections, Dr. Kurt Williams, director of the Oregon Veterinary Diagnostic Laboratory at Oregon State University, told The New York Times. Usually dogs recover from kennel cough, for example, within seven to 10 days. However, this outbreak is different.
“In these dogs, either it lingered for longer or it took a downward spiral and led to very serious outcomes, including death,” Williams said. It seems that serious outcomes are more likely to happen in older dogs or those with existing health issues, The New York Times reported.
What is causing the dog respiratory infection?
The cause of the outbreak among U.S. dogs is still unknown. However, some scientists think the culprit is a type of “funky bacterium” that has never been seen before, based on samples gathered from dogs in three states.
“It’s smaller than a normal bacterium in its size and in the size of its genome,” Dr. David Needle, a senior veterinary pathologist at the University of New Hampshire, told NBC News. “Long story short, it’s a weird bacterium that can be tough to find and sequence,” he said. (Sequence refers to analyzing an organism’s DNA code.)
Needle and his team have been tracking the outbreak since last year. So far, they have genetically sequenced 30 clinical samples from dogs that fell ill in New Hampshire last year, as well as 40 dogs from Rhode Island and Massachusetts that got sick this year. Twenty-one of the 30 New Hampshire samples were identified as the same unusual bacterial species, NBC reported. And 7% of the Rhode Island and Massachusetts samples also contained the microbe, Needle told.
The researchers have yet to publish their findings in a peer-reviewed journal, but they’re sharing what they’ve found so that vets are kept as informed as possible. Needle’s team hasn’t been able to grow the bacteria in lab dishes yet, so they haven’t had the opportunity to directly test how antibiotics affect it, Needle told NBC News. However, they can pull some clues from its structure and genetic code.
The specific pathogen behind the ongoing outbreak hasn’t been identified, Needle stressed, and it’s still unclear whether the one they’ve found is the same one infecting dogs across the country. Needle thinks the newfound bacterium may have evolved from a microbe normally found in the dog microbiome — the collection of microbes and viruses that live inside and on the surface of their body.
Whatever its cause, the disease currently appears to be specific to dogs. There have been no reported cases in humans, Mike Stepien, a spokesperson for the the United States Department of Agriculture Animal and Plant Health Inspection Service, told NBC News.