Obesity in Dogs: New Findings from Nom Nom

While the obesity epidemic in humans has garnered its fair share of scientific interest and media coverage, the parallel epidemic in our companion animals has received far less attention. For several decades, veterinary researchers around the world have been studying different factors that contribute to canine obesity but the results have been inconclusive, partially because many of these studies have been conducted on relatively small groups of dogs or examined only a small handful of risk factors. However, a survey conducted on 4,446 dogs in the United States, one of the largest studies to date, has more closely examined the impact of different risk factors, with a special emphasis on feeding and nutritional practices. 

“While this isn’t the first study to examine the effect of feeding practices on weight issues, it is one of the most detailed. We looked at many different food types, including dry, fresh, canned, raw, dried/dehydrated, and combination diets, several of which have not been previously studied with respect to weight. We discovered that compared with fresh food, dry food is strongly associated with overweightness and obesity. This has previously been found in cats but not in dogs,” said LeeAnn Perry, first author on the study, which has recently been published in bioRxiv, an open access preprint repository. 

This study is also the first to identify supplementation with probiotics (live microorganisms with beneficial health effects) as a potential protective factor against obesity. This effect was found to be specific to probiotic supplements, as other forms of nutritional supplementation, including fish oil, herbal remedies, and multivitamins, were not found to be associated with weight.

In addition to these novel discoveries, findings from previous studies that found relationships with neutering, age, exercise, temperament, and home environment were confirmed. Specifically, weight issues were more prevalent in neutered dogs, older dogs, less active dogs, dogs with increased appetite and food motivation, and dogs living in rural areas or with other dogs. Furthermore, findings from other studies that found associations between excessive treat feeding (with over 10% of calories coming from treats) and overweightness and obesity were confirmed; however, no effect was found with moderate treat feeding. This study’s replication of these known relationships supports the validity of the novel results.

“This is an important study that suggests that the secret to canine health lies primarily in their diet and lifestyle. These findings can be relevant to the veterinary communities in recommending lifestyle approaches to help curb the obesity epidemic in canines. A limitation of this study is that we do not understand all the mechanisms causing overweightness and obesity in dogs. Perhaps dietary ingredients influence the gut microbiomes, which influence a myriad of physiological events eventually resulting in obesity. Identifying the link between the gut microbiome and body weight in dogs can be very interesting,” said Aashish Jha PhD., another author on the study.