Blame it on the Genes: Why Labrador's are Always Hungry

     Labrador Retrievers are known for their love for food which causes them to be overweight. A study published on March 6th discovered why some labs are more likely to be overweight than others. The researchers found that genes play a huge role in why most labs are obese. In the past, researchers identified a gene called POMC, this gene makes some labs more likely to over eat, but its not that simple. Scientists studied 241 British Labs, looking at their DNA, body condition, behaviors with food, and how we could manage their weight/diet. There is another gene other than POMC that is liked to obesity in labs called the DENND1B. The labs that had the DENND1B gene contained around 8% more of body fat compared to the labs lacking that gene. This gene not only plays a role in dog obesity but humans as well, impacting how the brain responds to food. Researchers used the information they gathered from the study and created the "risk score",  which helped predict how much more likely a lab is to become overweight. The dogs that were always begging for food, getting into human food, and or just obsessing over food were the dogs with "obesity-prone" genes. There are ways to help the dogs that struggle with their weight, such as strict feeding schedules and not giving them table food. You don't need to pay a bunch of money to genetically test your dog for these genes- just paying attention to their behaviors with food can tell you a lot. 

    Working at a vet hospital, I really do see more overweight labs than any other breed. Not only are they beggars but they're notorious for eating foreign objects. It's really interesting to see how genetics gives us an explanation for why so many labs are relentless when it comes to food. I think it's important for everyone, not just people who work in the veterinary field to know there is gene like DEEND1B making labs biologically more food driven. It helps us be more empathetic towards owners that are truly trying to put their dogs on diets and stick to a feeding schedule. There are resources that can help guide owners when it comes to putting their dog on a diet to better maintain a healthy lifestyle for them. 

Why are Labrador and Flat Coated Retrievers prone to obesity?

 

    In a recent article in the U.S. News and World Report Dennis Thompson describes the results of a recent study examining the causes of obesity in Labrador Retrievers. This British study found that nearly 25% of Labrador Retrievers and 66% of Flat Coated Retrievers have a gene that makes them more likely to be obese. This mutated gene, called POMC, causes dogs to feel hungrier and burn less calories. Dogs with the POMC gene got hungry faster between feedings, despite not needing to eat more at meal times in order to feel full. Furthermore, the study found that these dogs also burn 25% less energy while resting than dogs without the gene, meaning they should actually be fed less. The POMC gene prevents dogs from making beta-melanocyte stimulating hormone and beta endorphin, which are both important in hunger and energy usage.

    The study found that when fed a meal Labs with the mutation did not eat more then Labs without the mutation. This indicated to scientists that dogs with the mutation did not need to eat more to feel full. However, in between mealtimes a sausage was placed in a box with a perforated lid, and dogs with the POMC mutation tried significantly harder to get the sausage. This indicated to scientists that they got hungrier between meals than dogs without the mutation. Drugs are currently in development for the POMC mutation can also occur in humans.

    In my opinion this article is important because it helps to inform owners of Labrador and Flat Coated Retrievers of a health condition that could be affecting their dogs. It allows them to make more informed decisions that will affect the health of their four legged companions. This article informs others who may want to get a Lab or Flat Coated Retriever about the health needs of the dog they may get. Furthermore it also makes clear to the audience that obese dogs are not always caused by negligent owners.

Of Canines and Obesity

Many people in the United States own dogs, and much of the time, regular exercise and walks keep these dogs filled with energy, playing with and following their owners with vigor. However, just like humans, dogs can become lethargic and eat too much, becoming overweight and not wanting to move much at all. The dog breed that seems to have the most trouble with this specific problem is one of the more popular breeds in the United States, the Labrador retriever.

Researchers from the Cambridge University labs has concluded that this abnormality is due to a DNA variation that keeps the brain from sending signals to the body that it is satisfied. Most of the time, when animals eat food, receptors in their brain make sure to activate when too much food enters the body. This sometimes manifests into a stomach ache to warn the body that the amount of food is excess, or in a more extreme case, send a message to the body to throw up to get rid of said excess food. However, in some animals like the Labrador retriever, the receptors are damaged by a gene variation, and up to 23% of all Labrador retrievers have at least one copy of this variation.

This gene being affected is called pro-opiomelanocortinm or POMC for short, and it codes for a protein of the same name.This gene controls hunger and fullness, and a variation can cause a delay or absence of feeling full. According to the article "the brains of Labrador retrievers may be hard wired for obesity," but as Eleanor Raffan, the author of the journal Cell Metabolism, says, it's "not a straight forward picture." What is straightforward is that when numerous dogs were studies and had their behavior profiles analyzed, it was discovered that in the POMC, there was a deletion of the 14th base pair resulted in a β-MSH and β-endorphin break, and that break is related to fat creation and increased body weight. In an interesting turn of events, most of the endorphin breaks happened in service dog, which prompted scientists to learn more about the gene so that they could try and find a connection between humans and dogs in terms of the POMC gene, since both species have the variation in slightly different forms.

Finding out if the genes in Labrador retrievers correspond to human genes would be very beneficial to human health because scientists can see what happens in human minds to trigger people to eat more then they should, and if they can isolate and fix the gene, or at least keep tabs on it, then work for a cure to obesity could be in the works, and that project would be worthwhile to the entirety of human health, as well as animal health if the Labrador genes are isolated and studied too.