Labrador Retrievers are adored worldwide for their sweetness, loyalty, and famously cheerful personalities. But there’s another trait Lab families know all too well: they love to eat. For decades, breeders, veterinarians, and owners have managed their voracious appetite without truly understanding what was different.

That changed when Dr. Eleanor Raffan and her research team at Cambridge University made a discovery that is reshaping our understanding of obesity risk in Labradors and providing powerful new insights for veterinarians and dog owners.

What began as a straightforward investigation into canine obesity quickly became something far more groundbreaking. Dr. Raffan analyzed thousands of Labradors and scanned their entire genomes in search of genetic variants associated with weight gain. One gene emerged as the strongest signal: DENND1B.

Previously linked to immune function and asthma risk in humans, DENND1B wasn’t a gene anyone expected to be connected to weight regulation in dogs. Its significance stunned the team.

“We chased down what’s going on with the biology of our top hit, a gene called DENND1B, and discovered that it affects a pathway in the brain which controls whether we feel hunger and how much energy we expend each day,” said Dr. Raffan.

By uncovering this surprising connection, the Raffan Lab developed a polygenic risk score, a tool that combines the influence of multiple gene variants, to identify dogs with a high or low genetic risk of obesity.

The implications were immediate and profound.

Dogs with high genetic risk weren’t simply “food motivated”—they were biologically greedier. Their hunger signaling worked differently. Owners of these dogs had to work dramatically harder to maintain a healthy weight. By contrast, dogs with low genetic risk tended to stay lean far more easily.

This research also revealed one more twist:
Chocolate Labradors carry an extra dose of these “greedy genes,” helping to explain why they can be more prone to weight gain.

The global scientific community took notice. Dr. Raffan’s discoveries have been featured internationally and highlighted in Science, which is regarded as one of the most prestigious scientific journals, underscoring the exceptional impact of her discovery.

Today, CHF is proud to recognize Dr. Eleanor Raffan as our third finalist for the 2025 Canine Health Discovery of the Year Award. Her research gives veterinarians and owners new tools to understand—and support—the dogs they love. It also demonstrates the transformative results possible when we fund rigorous, curiosity-driven canine health science around the world.

Join us next week in Orlando, Florida, as we celebrate this extraordinary breakthrough and reveal the inaugural Canine Discovery of the Year Award recipient.