As Bird Flu Spreads, Disease Trackers Set Their Sights on Pets

Trupanion, a Seattle-based pet insurance company, is partnering with the Centers for Disease Control and Prevention to create a disease tracking system for pets, the company announced this week. The system will draw on insurance claims submitted to Trupanion in real time when sick dogs and cats visit the veterinarian.

“The concept is to proactively detect potential threats to pets and public health,” said Dr. Steve Weinrauch, the chief veterinary and product officer at Trupanion.

The effort, which also includes academic scientists and other companies in the pet industry, is still in its early stages. Initially, it will focus on bird flu, a virus that has been spreading through American dairy cows and spilling over into domestic cats.

“This is a really important public-private partnership that is going to help fill some important gaps,” said Dr. Casey Barton Behravesh, who directs the C.D.C.’s One Health Office, which focuses on the connections between human, animal and environmental health.

It’s one of several ongoing efforts to address such gaps, which extend far beyond bird flu. Like most other countries, the United States has no comprehensive national system for tracking diseases in pets. While the C.D.C. is charged with protecting human health and the Department of Agriculture focuses on farm animals, companion animals tend to fall through the cracks.

“This is a population that is a little bit lost in the shuffle,” said Dr. Jennifer Granick, a veterinary internist at the University of Minnesota, who is one of the founders of a separate effort to create a disease surveillance system for pets.

It’s a public health blind spot that leaves both animals and people at risk, experts said. Many infectious diseases — including bird flu, Covid-19 and mpox — are zoonotic, which means that they can spread from animals to humans and back again. And there are few animals that people have closer contact with than those that live in their homes.

Companion animals also serve as a bridge between the natural and the human world and can be sentinels for shared health risks.

“I think if you had to pick one group of animals to invest in and really get good health tracking information on, it would be pets,” said Dr. Sarah Hamer, a veterinary epidemiologist at Texas A&M University.

Pet pathogens

Scientists have known for years that cats are susceptible to bird flu, which they can catch when preying on infected wild birds. But the dairy outbreak has created new risks; since late March, dozens of bird flu cases have been confirmed in American cats, some of which were infected after lapping up virus-laden milk. (Other cases have been more mysterious, including several recently reported infections in indoor cats with no known exposures to the virus.)

Bird flu infections in any mammals are cause for concern, giving the virus opportunities to evolve into a bigger threat to humans. “But I think it’s really important that we focus heavily on cats,” said Kristen Coleman, an infectious disease researcher at the University of Maryland.

Cats infected by wild birds could bring the virus home with them, passing it on to their owners, while those that prowl dairy farms could transport the virus off the premises, spreading it to animals in the wild.

To date, however, cats have been a relative afterthought in bird flu surveillance. “Most of the funding — government funding, anyway — is going toward surveillance in humans and dairy cattle,” said Dr. Coleman, who is working to establish a flu surveillance program at animal shelters. “And I see a gap there with companion animals.”

There have been many obstacles to creating surveillance systems for pets. Historically, many veterinarians worked in solo practices, keeping records in their own idiosyncratic ways. (Standardized diagnostic codes are not widely used in veterinary medicine.)

And when it came to disease monitoring in animals, many nations, including the United States, prioritized farm animals. “Governments just don’t put any money into companion animal surveillance,” said Dr. Scott Weese, an infectious diseases veterinarian at the University of Guelph in Ontario.

That has sometimes left experts scrambling to make sense of potential new threats. After veterinarians across the United States began reporting a surge of coughing dogs last fall, headlines warned that a mysterious new dog disease might be sweeping the nation.

But respiratory diseases periodically flare up in dogs. The lack of surveillance meant that there was no hard data on how many dogs were sick last fall — or how unusual any uptick might be. “That really ties our hands when we’re trying to sort out these issues and figure out signal versus noise,” said Dr. Weese, who is one of the experts working on the new Trupanion-led surveillance effort.

After months of fevered speculation, the tide of coughing canines ebbed, with no real evidence that a new dog disease was stalking the nation.

Real-time results

Advances in technology and changes to the veterinary industry, including the rise of large veterinary chains and the increasing use of pet insurance, have made it more feasible to collect large volumes of health data on pets.

Trupanion now insures more than one million pets, and more than 10,000 clinics across North America use the company’s software to submit insurance claims. A sudden spike in claims for coughing dogs in California or feverish cats in New York might be an early signal of a disease outbreak. In the long term, the company hopes to build a system that can flag any such aberrations automatically, Dr. Weinrauch said. But it will start with more focused investigations, such as scouring the data for signs that bird flu might be spreading in cats.

At the University of Minnesota, Dr. Granick and her colleagues have been building the Companion Animal Veterinary Surveillance Network, or CAVSNET, which automatically collects electronic health records from veterinary practices nationwide. The system, which currently receives data monthly from about 1,400 clinics, is not yet equipped for real-time outbreak detection, Dr. Granick said.

But it was inspired by a similar system in Britain, the Small Animal Veterinary Surveillance Network, or SAVSNET, which has provided proof of principle. Run by a small team at the University of Liverpool, the network receives veterinary records and lab results from across the country, often in nearly real time.

“There’s a map of the U.K., and it pops up with ‘A cat was just seen vomiting,’ ‘A dog was just seen with respiratory disease,’” said Dr. Alan Radford, a veterinary infectious disease expert and SAVSNET investigator.

And in January 2020, when a veterinarian in Liverpool called to report that she was seeing a lot of vomiting dogs, Dr. Radford and his colleagues were able to quickly confirm that the outbreak was real. Over the next few months, the team conducted a full epidemiological investigation, providing regular public updates and linking the outbreak to a new variant of a typically mild canine virus. By April, the outbreak had ended.

Once they’re up and running, these sorts of surveillance systems can provide a wide variety of insights. For example, Dr. Granick and her colleagues are already analyzing the CAVSNET records to learn more about antibiotic prescribing practices in veterinary medicine. As in human medicine and agriculture, the overuse of antibiotics in pets could drive the emergence of drug-resistant superbugs.

In some cases, it might be easier to track public health risks in pets than it is in people. Lyme disease, a tick-borne illness that has been expanding its geographic range, affects both dogs and people. Dogs, however, are routinely tested for antibodies to the bacteria that cause Lyme, while people are not.

A new study, which has not yet been published in a peer-reviewed journal, suggests that public health officials might be able to spot rising Lyme disease rates in dogs up to two years before case reports begin rising in people. “Those diagnoses are happening earlier in dogs than they are in humans,” said Dr. Audrey Ruple, a veterinary epidemiologist at Virginia Tech and an author of the study.

In the United States, the Companion Animal Parasite Council already tracks the prevalence of Lyme disease in dogs using test results collected from major veterinary laboratories. Every month, the council publishes maps of the prevalence of Lyme, and other parasitic diseases, in every county.

“Our goal was to let people know what is in their backyard,” said Dr. Christopher Carpenter, a veterinarian and executive director of the council.

On a county level, the council’s calculations of Lyme disease rates in dogs are correlated with case numbers in people, scientists found. That suggests that even people without pets could use the maps to gauge their own, ever-evolving risk, Dr. Carpenter said.

Although the council’s disease tracking efforts focus primarily on parasites, it has started to expand to some viral and bacterial diseases, Dr. Carpenter said. “We need to do a lot more surveillance.”