Labrador retrievers could make a pretty good claim for being America’s dog. Last year, according to the American Kennel Club, they were the most popular purebred dogs in the country for the 25th year in a row.
There’s something else very American about Labs: They have a tendency to get fat.
People whose dinners are interrupted by maniacally begging Labs know this, and so do the veterinarians who treat the diabetes and other health woes of chunky dogs. When the U.S. Association for Pet Obesity surveyed vets in 2012, they classified nearly 60 percent of their Labrador retriever patients as overweight or obese; other large-scale studies here and in other countries have found that about half fit that description.
But it turns out that the pudgy pups, poor things, may not be able to help it. Overeating, a new study found, is very possibly in Labs’ genes.
Eleanor Raffan, a veterinary surgeon and geneticist at the University of Cambridge who had studied human obesity, figured Labrador retrievers’ battles with bulge might be rooted in genetics. To find out, she and colleagues looked at three obesity-related genes in fat and slim Labs and found a variation in one, known as POMC, in 10 or 15 obese dogs, but only two of 18 lean ones. The variation — in this case, part of the gene was missing — can prevent dogs from feeling satiated after eating.
In a larger sample of 310 Labradors, the researchers found that the POMC deletion was more common among heavier dogs who, according to a survey that questioned owners about their dogs’ affinity for scavenging and eating non-food items such as socks, were more “food-motivated.”
When they widened the scope to a sample of 411 pet Labradors in the United States and the United Kingdom, the researchers found the POMC deletion in 23 percent of all the dogs. Of 38 other breeds tested, only flat-coated retrievers, which are related to Labs, also had the deletion.
