UNH scientists track clues to mysterious illness sickening pet dogs | Animals

Dogs had a cough — similar to kennel cough but lasting for weeks, even months — and some developed pneumonia. Antibiotics seemed to have little effect.

Since then, the New Hampshire Veterinary Diagnostic Laboratory at the University of New Hampshire has been at the forefront of tackling the mystery, and scientists here have found some promising clues. Working with UNH’s Hubbard Center for Genome Studies, researchers have identified a previously unknown bacteria that could turn out to be the culprit.

Dr. David Needle, senior veterinary pathologist at the NHVDL, said early on, he was hearing anecdotal reports about “atypical” respiratory disease in dogs, but nothing had been sent to his lab for testing. Impatient for data, he delivered test kits to veterinarians in Manchester and on the Seacoast who were reporting cases, and asked for nasal swabs from sick dogs.

The NHVDL staff works closely with colleagues at the Hubbard Center, which does state-of-the-art DNA sequencing. Needle reached out to Dr. Kelley Thomas, director of the center, and Thomas immediately “was 100% on board,” he said.

“He has a dog,” Needle said.

It’s a close partnership that serves the state well, Needle said. “The skills and team that we’ve developed, and this collaboration, allows us to really figure things out far more than we can with routine diagnostic work,” he said.

The Hubbard Center was at the epicenter of testing during the pandemic public health emergency. “This is where we managed to process two million COVID samples,” Thomas said in an interview at his lab.

The high-tech equipment they use has revolutionized this area of science, said Thomas, who is also a professor of molecular, cellular and biomedical sciences. “We went from sequencing 100 things at a time to hundreds of millions of things at a time,” he said.

During the recent visit, the equipment was testing for PFAS chemicals in soil samples taken across the state.

The canine respiratory illness posed a unique challenge, Thomas said. “It wasn’t something that we knew,” he said.

All they had to go on were those swabs from the noses of sick dogs; they had no tissue samples typically obtained through a necropsy (the animal equivalent of an autopsy).

“No one is going to sacrifice a dog to get the pathology tissue sample,” Thomas said.

Researchers used a technique called “shotgun metagenomics,” NHVDL’s Needle said, to generate “an incredible amount of data.”

Graduate student Lawrence Gordon was tasked with sifting through that haystack of data, looking for a promising needle.

“We didn’t find a known pathogen or anything related to a known pathogen,” Needle said.

But they did find something.

They call it BARDiD — “bacteria associated with respiratory disease in dogs,” Needle said.

“This is a bacteria that is unusual, and its closest relative is an organism associated with human respiratory disease,” Thomas said.

The scientists are cautious about declaring a definitive link between this bacteria and the canine respiratory illness.

But one thing correlates to what veterinarians have reported, he said: “The type of bacteria it is would make it not susceptible to certain antibiotics.”

Thomas from the Hubbard Center said they haven’t proven that the bacteria is the “causal agent” for this particular illness. But he said, “That association is very strong.”

The scientists have not been able to culture the novel bacteria — something that it has in common with that particular bacteria that’s associated with respiratory disease in people. “They were unable to culture that as well,” he said.

That does present a challenge for the researchers. “We have to work harder,” Needle said.

Knowing they needed more research, the UNH teams released a white paper about their work and sent it out to veterinary professional associations in New England. “It was something we would not normally do, but this was a public health service,” Needle said.

They soon started receiving more swab samples from veterinarians in other states, including Colorado and Oregon. “We started to find the potential pathogen all over the place, associated with disease,” he said.

They also tested tissue samples stored in the NHVDL’s necropsy “biobank,” samples taken from animals before the outbreak. “We went back through the biobank and did not find BARDiD,” Needle said.

They checked the medical literature but found no similar reports. “It’s something that seems to be new to dogs,” Needle said.

The NHVDL, which has been at UNH for more than 50 years, moved into its current building in 2015. It’s an idyllic setting on the edge of campus, with birdsong in the air and white-fenced corrals with horses across the road.

Clients include veterinarians, state agencies and farmers, as well as zoos and aquariums from all over the country. Pathologists and technicians work with the state Department of Agriculture to monitor animal health and investigate diseases affecting livestock.

The lab’s four pathologists also double as UNH faculty, and work with students doing undergraduate research projects. Microbiology, parasitology, mycology, serology and histology are all specialties of the lab staff.

“It’s just like in human medicine,” Robert Gibson, managing director of the NHVDL, said. “But in veterinary medicine, there’s all sorts of unique pathogens and flora that animals have.”

Automation drives efficiency here. High-tech mass spectrometry can identify bacteria in minutes, a process that used to take days, Gibson said. Robotic equipment helps scientists examine biopsy tissues to look for pathologies such as cancer.

With all this equipment and expertise, the UNH scientists were uniquely positioned to investigate the mysterious new illness afflicting pet dogs.

The lab conducts necropsies on all kinds of animals that die from illnesses, including seals, dolphins and zoo animals. With the threat of avian flu, they’ve been examining lots of chickens lately.

A particular specialty of the NHVDL is looking for pathogens that can spread from animals to humans. “That’s actually where our lab is the most important to our state, is our work making sure things don’t go from animals to people and cause illness, or into the food chain,” Needle said.

“We’re a public health lab and we’re a food-chain security lab,” he said.

The necropsy area of the lab is off-limits to anyone who hasn’t been vaccinated against rabies, which is highly contagious — and fatal. “If you get it, you only get it once,” Needle said.

What are the implications for human health from the new canine disease? “There have been no human cases associated with it that we have heard about,” Needle said.

”Is it possible? Sure. Is it probable? No,” he said. “Because it hasn’t happened, and it’s been all over the country.”

With another summer upon us, the NHVDL is again receiving new samples from veterinarians around the country, including the first case from California. The lab recently got a $300,000 grant from the American Kennel Club’s Canine Health Foundation to support its research into the new illness.

The plan is to sequence the entire genome of the bacteria. They’ll also look at the microbiomes of the dogs that got sick to see what else may be going on.

In the end, they hope to produce the data for scientists on the clinical side to start working on treatments.

Needle has two dogs living in his household — Freddie, a happy Labrador retriever puppy, and Chuck, a corgi-Rottweiler mix with an attitude. “He hates me,” he said resignedly. “He loves my wife, he tolerates my sons, and he does not like me.”

Needle’s dearly departed dog, Delilah, a Lab/pitbull mix who disdained other canines, played a key role early on in research into the respiratory illness, Needle said. She was the perfect negative control for their study, he said with a grin: “She had not had contact with another dog for 12 years.”

Needle understands why there has been so much concern surrounding this new illness, and interest in solving the mystery.

“Everyone loves their dog,” he said.