Gene mutation associated with obesity in dogs

Q:Our 3-year old Labrador retriever, Clyde, is obese. We feed and exercise him according to his veterinarian’s instructions, but he keeps gaining weight. 

Clyde’s thyroid glands are functioning as they should, and all other lab work is normal. We’ve never had this problem with any of our other dogs, so we’re wondering if Clyde could have inherited his obesity. What do you think?

A:Among the dog breeds, Labrador retrievers have the highest prevalence of overweight and obesity; and they are the most highly food-motivated of all breeds.

A recent study indicates these characteristics may be inherited. Researchers found that in Labs, a mutation of the POMC (pro-opiomelanocortin) gene is associated with increases in obesity and food drive. In dogs and humans, the POMC gene affects eating behavior.

The gene mutation also was found in flat-coated retrievers, a breed closely related to Labs. Both were derived from the St. John’s water dog, a breed that is now extinct. The gene mutation was absent in 38 other dog breeds tested.

The prevalence of obesity in dogs living in developed countries is 34 to 59 percent. Scientists hope that further research on canine obesity will help improve weight management in both dogs and humans. In humans, more than 100 genes have been found to influence body weight.

Lee Pickett, V.M.D. practices companion animal medicine in Pennsylvania. Contact her at askdrlee@insurefigo.com.