The “Lab” Results Are In: Genes Might Be to Blame for Retrievers’ Obesity

If you’ve ever had a Labrador retriever, you know about one of the breed’s notable traits: an unrelenting appetite. The dogs will devour anything from socks to rocks, and given the chance, they can be prone to eat themselves into obesity. By one estimate, nearly 60 percent of all Labradors are overweight or obese.

In fact, the dubious honor of being named Britain’s fattest pet went to a 176-pound Labrador named Alfie, who was rather uncharitably described by one official as “a massive blob with a leg at each corner.”

Labradors have been caught sitting under an apple tree waiting for the fruit to fall and dragging their owners to a spot in the grass where they once found a discarded kebab years before.

Is it a character flaw? Are they incorrigible gluttons? Scientists at Cambridge University say no: Labradors can’t help it; it’s in their genes.

Researchers studying 310 Labradors found that many of them were missing all or part of a gene known as POMC, which is known to regulate appetite in some species and to help sense how much fat the body has stored. Without it, the dogs don’t know when they’ve had enough, so they just keep eating and eating.

The POMC gene is also present in humans, and while cases are very rare, there are obese people with a similar gene deficiency.

The Labrador study “reminds people that hard-wired biology explains why some animals, like affected Labradors and indeed some humans, are more prone to obesity than others,” said Eleanor Raffan, the lead researcher. “Their genes mean they are more hungry all the time.”

Scientists have found the POMC mutation to be widespread in only one other dog breed: flat-coated retrievers, which are cousins to Labradors. Dr. Raffan said the scrambled POMC gene partly explains why Labradors are easy to train as service dogs: “They will be willing to work harder” for a treat, she said.

The scientists think the mutation arose in an earlier breed that Labradors are descended from, the St. John’s water dog, which fishermen used to retrieve nets from Newfoundland’s icy waters.

“The tendency to eat every food that’s thrown your way would have been sensible” under those conditions, Dr. Raffan said, but for a modern Labrador living as a pet, the mutation is no longer beneficial.

Canine obesity is on the rise generally, but for most dogs, rich food and lack of exercise are to blame, not genes.

Alfie grew so fat that it took four people to lift him. Breathing problems and bone damage prompted a crash diet, but he eventually had to be euthanized.

We’ve known for years that labradors are different from other large breed dogs in that, when fed the recommended amount of food on the dog food bag, they tend to be overweight and seem to have a difficult time losing the extra pounds. While it may be true that genetics plays a role in this, regular exercise at least twice daily and using an 8 ounce cup to measure the food at the low end of the manufacturer’s recommendation can keep most labs in excellent condition. Remember that the super premium foods currently being fed by so many of our clients are designed to be fed at the rate of one cup per 25-30 pounds depending on exercise level. This is a big change from the lower caloric density foods of yesteryear that were fed at the rate of one cup per 20 pounds. If you are a regular newsletter reader you’ll remember that we recently published a list of the calories in popular dog treats which was, in some cases, a real eye opener. If you would like a copy of that list, let our receptionists know.


Pittsburgh Spay & Vaccination Clinic is a state-of-the-art, full-service suburban veterinary facility serving the Pittsburgh Area since 1980.. We offer diagnostic, medical, surgical, and dental care to dogs, cats, ferrets, rabbits, and pocket pets in the Pittsburgh area.

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