by Katy Walsh
24% of the UK population own a dog and around 50% of these are classed as obese. This excess weight can lead to a whole range of problems such as heart failure, arthritis and even diabetes (yes, it’s not just humans!) which ultimately leads to a shorter, more painful life.
Labrador retrievers are the most popular breed, due to their friendly, hard-working and playful nature. Despite their usual boundless energy, it isn’t uncommon to spot a podgy Labrador waddling down the street. In fact, Labradors have been shown to be the most likely breed to become obese, but why? Is it a slower metabolism? Do they store fat more efficiently? Or have they perfected those puppy eyes, to break even the strongest of wills?
It turns out Labrador Retrievers, and the closely related Flat Coated Retriever (FCR) have a genetic mutation that prevents them from feeling full! The mutation is found in the pro-opiomelanocortin (POMC) gene that is expressed in neurons in the brain. THE POMC gene encodes a set of proteins that play a role in appetite control. The mutation takes the form of a 14 base pair deletion in the DNA that disrupts the resulting proteins from being made correctly. The lack of correct proteins leaves the canine with a big appetite and no signals to tell them they are full.
Labradors intelligence and eagerness to please makes them a perfect choice for assistance dogs. Surprisingly, the POMC mutation is found more frequently in assistance dogs than those bred as pets! But, knowing that assistance dogs are trained using a food reward system, it isn’t actually all that surprising that those with the mutation are more likely to be selected and bred. As they are always hungry, they are more than willing to do tasks for treats!
Given the chance, Labradors and FCRs would eat themselves to the point of physical sickness. Luckily, owners are here to step in and control how much food they’re given and how often to save them from themselves! This could be why dogs have altered their behaviour; to guilt us into giving them more food, developing traits like begging and salivating.
I know what you’re thinking: ‘Is it possible my constant chocolate craving is because I have the Labrador mutation?! Am I genetically programmed to finish this entire tub of Ben and Jerrys?!’ You could be! Whilst there is no proof this mutation exists in humans, the canine POMC gene is 79% similar to the human equivalent, thus has the potential for a similar mutation which effects human appetite. Could this be the key to tackling the growing obesity epidemic?