1 in 4 Labradors at risk of obesity due to genetic mutation

By Sharin Hussain via SWNS

One-in-four Labradors are likely to get fat due to a genetic mutation, according to a new study.

Researchers find around 25 percent of the breed are "hard-wired" to face feeling hungry all the time and burning fewer calories.

And the same mutation affects two thirds of flat coated retrievers.

The breed is renowned for piling on the pounds and the study by University of Cambridge scientists says owners must be strict with feeding and exercising their Labradors to keep them slim.

Lead researcher Doctor Eleanor Raffan said: “We found that a mutation in the POMC gene seems to make dogs hungrier.

"Affected dogs tend to overeat because they get hungry between meals more quickly than dogs without the mutation.”

Around 25 percent of Labradors and 66 percent of flat coated retriever dogs have the POMC gene, which plays a critical role in hunger and energy.

The mutation changes the way Labradors and flat coated retrievers behave around food.

The study, published in the journal Science Advances, found that although they don’t need to eat more to feel full, they are hungrier in between meals.

Dogs with POMC were found to use around 25 percent less energy at rest than dogs without it, meaning they don’t need to consume as many calories to maintain a healthy body weight.

Dr. Raffan said: “All owners of Labradors and flatcoated retrievers need to watch what they’re feeding these highly food-motivated dogs, to keep them a healthy weight.

“But dogs with this genetic mutation face a double whammy: they not only want to eat more, but also need fewer calories because they’re not burning them off as fast.”

The POMC mutation was found to alter a pathway in the dogs’ brains associated with body weight regulation.

The mutation triggers a starvation signal that tells their body to increase food intake and conserve energy, despite this being unnecessary.

Dr. Raffan added: “People are often rude about the owners of fat dogs, blaming them for not properly managing their dogs’ diet and exercise.

“But we’ve shown that Labradors with this genetic mutation are looking for food all the time, trying to increase their energy intake.

“It’s very difficult to keep these dogs slim, but it can be done.”

Researchers suggest spreading out each daily food ration by using puzzle feeders or scattering the food around the garden so it takes longer to eat.

Data was collected from 87 adult pet Labrador dogs, all at a healthy weight or moderately overweight.

The researchers found that dogs with the POMC mutation tried significantly harder to get the sausage from the box than dogs without it, indicating greater hunger.

They were given a can of dog food every 20 minutes until they chose not to eat any more and found that the dogs with the POMC mutation didn’t eat more than those without it.

This showed that they all feel full with a similar amount of food.

The dogs were then allowed to sleep in a special chamber that measured the gases they breathed out and revealed that dogs with the POMC mutation burn around 25 percent fewer calories than dogs without it.

The new findings are consistent with reports of extreme hunger in humans with POMC mutations, who tend to become obese at an early age and develop a host of clinical problems.

Drugs in development for human obesity, underactive sexual desire and certain skin conditions target this brain pathway.

A mutation in the POMC gene in dogs prevents production of two chemical messengers in the dog brain, beta-melanocyte stimulating hormone and beta-endorphin, but does not affect production of a third, alpha-melanocyte stimulating hormone,

The team suggests that beta-MSH and beta-endorphin are important in determining hunger and moderating energy use, and their role is independent of the presence of alpha-MSH.