The susceptibility to obesity varies between dog breeds which suggests, despite environmental factors as reduced exercise and access to high-calorie food, the influence of genetic factors. In the Labrador retriever breed and the closely related Flat coated retriever, a POMC (pro-opiomelanocortin) mutation has been found to disrupt the production of the neuroactive peptides ß-MSH and ß-endorphin, both implicated in energy homeostasis. Furthermore, the mutation is associated with greater weight, adiposity and food motivation in affected dogs. Therefore, the mutation is especially common in assistance dogs. Aside from the Labrador retriever and the Flat coated retriever, the mutation could not be found in other breeds.
about one week after arrival of the sample in the lab