July 29, 2025, 8:54 am | Read time: 6 minutes
Many dogs are overweight—but why is that? A new U.S. study on obesity in dogs involving nearly 14,000 dogs shows that it’s not just treats that cause weight gain. Personality, breed, and the home environment also play significant roles in the battle against the pounds.
Researchers from the renowned Dog Aging Project wanted to know: Why do some dogs gain weight despite good care, while others remain slim even though they seem to eat everything? Using a special Dog Obesity Risk and Appetite (DORA) questionnaire that assesses appetite and feeding behavior, they collected extensive data from 13,890 U.S. dogs that participated in the Dog Aging Project between 2019 and 202—one of the largest long-term projects on canine health worldwide. The results were published in the journal “American Journal of Veterinary Research.”
In the U.S., 51 Percent of Dogs Are Considered Overweight
Overweight in dogs is not only widespread but also dangerous. In the U.S., 51 percent of all adult dogs are considered overweight, with far-reaching health consequences. “Overweight dogs are prone to numerous health issues, including skin diseases, diabetes, and arthritis,” Dr. Kate Creevy, Chief Veterinary Officer of the Dog Aging Project and professor at the Department of Small Animal Clinical Sciences at Texas A&M College of Veterinary Medicine and Biomedical Sciences (VMBS), told the science magazine “Phys.Org.” Additionally, excess body fat can significantly reduce life expectancy and quality of life.
The causes of overweight in dogs are varied: age, neutering, activity level—and increasingly, feeding behavior is coming into focus. Previous British studies showed that particularly “food-motivated” dogs are more often overweight. It is also known in humans that those who are very food-motivated tend to be overweight. The U.S. researchers wanted to know if these connections also apply to U.S. dogs and what role external factors, such as breed, household environment, or location, play.
“It is essential for veterinarians to develop a better understanding of obesity in dogs and whether it can be linked to social, environmental, or demographic factors so that we can provide every dog with the best possible quality of life,” Creevy said.
Food, Motivation, and Feeding Rules Were Central
The study analyzed data from 13,890 dogs from the Dog Aging Project, whose owners completed the DORA questionnaire.
Two factors were central in the data analysis:
- Food Motivation: How strongly does a dog react to food?
- Feeding Rules: How strictly does the owner control food quantity, snacks, and exercise?
Both values were given in percentages. Owners also assessed whether their dog was considered overweight in the past year.
Surprising Result: Strict Rules Don’t Always Help
The study revealed several intriguing insights: 1
- The more food-motivated a dog is, the more likely it is to be overweight. Even a small increase in “food greed” noticeably raised the risk.
- Strict rules by owners did not automatically have the desired effect. On the contrary, even with particularly committed owners, their dogs were often overweight. The reason could be that these owners are already responding to a problem—because their dog is particularly gluttonous.
- Dogs living in multi-dog households have an increased risk of being overweight. Perhaps because they eat faster in competition or beg more often.
- City dogs tend to have a larger appetite than their rural counterparts. Possibly because they are less often allowed to run freely or demand snacks more frequently out of boredom.
- The breed group also played a role: Dogs in the “Sporting” group (e.g., Labrador Retrievers) were 10.2 percentage points higher in food motivation than mixed breeds—a result supported by other studies.
“Our study confirmed that dogs in the Sporting group—which in our study group mainly consisted of Labrador Retrievers and Golden Retrievers—are more likely to have high food motivation,” Creevy explained. “Given that these are two of the most common breeds in the U.S., it is important for both veterinarians and dog owners to understand the nutritional management strategies necessary to achieve a healthy weight.”
The Role of the Breed Group Is Particularly Noticeable
The results confirm that overweight in dogs is not just a matter of food quantity or exercise but is closely linked to individual behavior patterns and environmental factors.
The role of the breed group is particularly noticeable: Certain genetic backgrounds, such as a known gene mutation in Labradors, could increase food motivation. It also shows that even committed owners with strict rules often have overweight dogs—possibly because stronger measures are needed for particularly food-motivated animals.
The tendency for owners to misjudge their own dogs underscores the importance of professional advice from veterinarians. They should help owners objectively assess feeding behavior and take appropriate countermeasures—tailored to the breed, living environment, and motivation of the dog.
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Study Shows Correlations, but No Causality
The study relies on a large database from the Dog Aging Project, with high methodological quality and a clear research goal. However, there are limitations: Most body conditions were assessed by owners themselves, not veterinarians, which can lead to misjudgments. Also, the corresponding question in the questionnaire was binary (“overweight: yes/no”)—fine gradations like on a scale were missing.
The BCS data from medical records were sometimes up to a year old. Furthermore, the influence of neutering status could not be separately evaluated, as only a few dogs were unneutered. Differences in the size of breed groups made comparability difficult. Finally, the study is cross-sectional—meaning it shows correlations, but no causality.
What Does This Mean for Dog Owners?
The results make it clear: Overweight in dogs is not a simple calculation error with food quantity minus exercise. Rather, many factors influence weight—especially the behavior of the dog and its owner. For particularly gluttonous animals, it is often not enough to simply give less food. Targeted strategies, clear structures—and often professional support—are needed.
The study is an important step in better understanding overweight in dogs. It shows that there is no “one-size-fits-all” solution. Instead, dogs need individual approaches—tailored to their personality, breed, and living situation. Veterinarians should help owners better understand their pet’s behavior and find the right path to a healthy weight.