Does your Labrador eat non-stop? Science has found a surprising answer (Photo: Shridhar Dixit/Unsplash)
According to a new study, if your Labrador seems to be hungry all the time, it might be because they actually are.
Previous research revealed that about 25% of Labradors carry a genetic mutation associated with obesity in other animals. Recently, researchers discovered that dogs with this mutation feel hungrier between meals and burn less energy than others.
“What we see in dogs is that they’re receiving this molecular hunger signal. As a result, they try to eat more and reduce energy expenditure,” explained Eleanor Raffan, a veterinarian and geneticist at the University of Cambridge and co-author of the new paper, published on March 6 in Science Advances.
In the new study, Raffan and her colleagues wanted to understand how the mutation, which affects a gene called pro-opiomelanocortin (POMC), impacts the lives of dogs that carry it.
They recruited dozens of dog owners in the UK who were willing to participate in a series of experiments. The first, dubbed the “sausage in a box” test, brought the Labradors to the laboratory about three hours after the dogs had breakfast.
The researchers showed each dog a sausage and locked it in a plastic box with holes so the dog could smell but not eat the treat. They then observed how the dogs interacted with the box and for how long.
They found that dogs with the POMC gene mutation were more focused on the sausage box, spending about twice as much time interacting with it. Next, they also asked the dog owners to conduct an experiment at home.
In this exercise, breakfast became an all-you-can-eat buffet, where dogs were given a new can of food every 20 minutes until they stopped eating, vomited, or reached the maximum limit of the experiment of about 3 kg of food.
On average, all dogs, whether they had normal POMC genes or not, ate about two kilograms of food, which is “a huge amount,” according to Raffan. However, dogs with the POMC gene mutation ate a little more, and dogs without the mutation were more likely to end the experiment by vomiting.
The result suggests that the mutation does not make a difference in how quickly dogs feel satiated. The greater focus on food by the group with the POMC gene mutation, however, suggests that these dogs would continue to seek more food if it wasn’t in front of them.
In another experiment, scientists also determined that dogs with the POMC mutation used less energy than their counterparts. Together, the experiments show the complex way the mutation affects a dog’s brain and body.
According to Raffan, the POMC gene mutation makes them want more food without actually making them enjoy a particular food more or needing more food to feel full. At the same time, it causes them to burn food more slowly.
“They suffer a kind of double whammy: eating more and burning fewer calories, which means they are predisposed to obesity in both directions,” Raffan explained. Dogs with the mutation can maintain a healthy weight, but they need their owner’s help to do so.
