How Science Went to the Dogs (and Cats)
“We have a responsibility to deeply understand these animals if we’re going to live with them,” Dr. Udell said. “We also have this great potential to learn a lot about them and a lot about ourselves in the process.”
Emily Anthes
Every dog has its day, and July 14, 2004, belonged to a boxer named Tasha. On that date, the National Institutes of Health announced that the barrel-chested, generously jowled canine had become the first dog to have her complete genome sequenced. “And everything has kind of exploded since then,” said Elaine Ostrander, a canine genomics expert at the National Human Genome Research Institute, who was part of the research team.
In the 20 years since, geneticists have fallen hard for our canine companions, sequencing thousands upon thousands of dogs, including pedigreed purebreds, mysterious mutts, highly trained working dogs, free-ranging village dogs and even ancient canine remains. Research on canine cognition and behavior has taken off, too. “Now dog posters are taking up half of an animal behavior conference,” said Monique Udell, who directs the human-animal interaction lab at Oregon State University. “And we’re starting to see cat research following that same trend.”
Just a few decades ago, many researchers considered pets to be deeply unserious subjects. (“I didn’t want to study dogs,” said Alexandra Horowitz, who has since become a prominent researcher in the field of canine cognition.) Today, companion animals are absolutely in vogue. Scientists around the world are peering deep into the bodies and minds of cats and dogs, hoping to learn more about how they wriggled their way into our lives, how they experience the world and how to keep them living in it longer. It’s a shift that some experts say is long overdue.
“We have a responsibility to deeply understand these animals if we’re going to live with them,” Dr. Udell said. “We also have this great potential to learn a lot about them and a lot about ourselves in the process.”
For geneticists, dogs and cats are both rich subjects, given their long, close history with humans and their susceptibility to many of the same diseases, from cancer to diabetes. Dogs have been an especially appealing target. Intense human selection, especially over the last few centuries, has created a staggeringly diverse collection of canines, from Chihuahuas to Great Danes, and hundreds of reproductively isolated breeds, which often suffer from high rates of disease.
In the 2000s, scientists identified the genetic underpinnings of a variety of canine traits, including curly coats and bobbed tails. They pinpointed mutations that could explain why white boxers were prone to deafness. And they found that corgis, basset hounds and dachshunds owed their stubby legs to a genetic aberration in a family of genes that also regulates bone development in humans.
These early studies “highlighted both the potential that we could learn from dogs, but also that we were going to need bigger sample sizes to do it really well,” said Elinor Karlsson, a geneticist at UMass Chan Medical School and the Broad Institute. And so, researchers began creating large citizen science projects, seeking DNA samples and data from dogs across the United States.
Pet owners rose to the challenge. The Golden Retriever Lifetime Study, which began recruiting in 2012, has been following more than 3,000 dogs in an effort to identify genetic and environmental risk factors for cancer, which is especially common in the breed. Since 2019, the Dog Aging Project, a long-term study of health and longevity, has enrolled nearly 50,000 dogs.
Dr. Karlsson’s own project, Darwin’s Dogs, is at 44,000 canines and counting. (Some 4,000 have had their genomes sequenced.) Researchers are mining the data for clues about bone cancer, compulsive behavior and other traits. Among the early findings: Although many behavioral traits, such as sociability and trainability, are heritable, they are widely distributed across the canine kingdom, and breed is a poor predictor of an individual dog’s personality.
This spring, Dr. Karlsson unveiled a much-anticipated expansion: Darwin’s Cats. “I’m a total cat person have never owned a dog,” she said. Later, in an email, she added, “I’d love to know if ‘cat sleeps on your head’ is influenced by genetics.”
These projects were made possible as genomic sequencing got faster and more affordable. But the “tremendous enthusiasm” of pet owners has been integral, said Dr. Ostrander, who now leads the Dog10K project, an effort to build a comprehensive global catalog of canine genetic diversity. Today’s dog owners know more about genetics and are highly motivated to participate in research. “People devote extraordinary amounts of time and money to canine health and canine care,” she said. “We care deeply that they live the best life they possibly can.”
The pet-health industry has blossomed and is producing data of its own. At Nationwide, which provides health insurance for pets, a veterinary analytics team has been combing through millions of claims to document the health problems common in dogs and cats of different breeds, sizes and ages. Mars Petcare, which owns multiple veterinary chains, hopes to recruit 20,000 canine and feline patients to contribute biological samples to a companion animal biobank.
