Home » Pet Health » Staying Healthy » Body Weight and Cancer Risk in Dogs


Obesity is one of the top health concerns in pets and some studies show that 58% of dogs are overweight or obese. Excess fat in pets increases the risk of several health disorders, including diabetes, arthritis, heart disease, and some cancers. Luckily, it is possible to make small and manageable changes that can impact your pet’s long-term health.

What is the relationship between obesity and cancer risk in dogs?

Fat in the body acts as an organ and excess fat deposition can alter the normal production of hormones and cell-signaling molecules. In humans, overproduction of these hormones and molecules can affect the normal process of cell growth and death, resulting in cancerous growths. Reports show that dogs with cancer are generally overweight or obese. For example, overweight dogs are more likely to develop mammary cancer than those with a healthy weight. Therefore, the overproduction of similar hormones and molecules may also contribute to cancer development, and this may be due to similar cell-signaling molecules causing the cancer cells to spread.

Is my pet overweight?

Vets can use a body condition scoring (BCS) system to measure your dog’s body weight. BCS evaluates physical features, including the shape of your dog when viewed from above or from the side, and how easily palpable their ribs are. The vet scores these features on a 9-point scale, with 1 representing an emaciated dog, 5 being ideal, and 9 representing a severely obese dog.

Alternatively, your vet can weigh your dog and compare it to the average weight for breed and gender. Your vet will typically measure your dog’s weight at every appointment. To keep track of your pet’s weight, vets recommend yearly check-ups.

How do I keep my dog at a healthy weight?

Your pet’s weight depends on the amount of food they consume and the exercise they receive. Too many treats and little physical activity will lead to weight gain over time. Before making any changes to your pet’s diet and activity, we recommend taking your pet to the vet for a physical examination. To maintain a healthy weight for your dog, you can try the following suggestions:

    • Diet and Feeding: The best way to maintain a healthy weight for your dog is to control their feeding times. Also, consider switching your pet to a portion-controlled feeding method. With this method, you can control the portion size at every meal while monitoring the overall caloric intake daily. Experts recommend this feeding method to lower the risk of obesity and related disorders.

Keep track of the amount of supplemental feeding (treats, chews, and table scraps) and consider limiting or replacing treats with lower-calorie snacks recommended by your vet. Also, remember always to have fresh water available for your dog.

There may be resistance from your pet over dietary change, so introduce changes slowly and be consistent.

    • Exercise: Exercise is essential for your pet’s weight and overall health. Reports show that increased exercise, with or without a change in diet, reduces weight and weight-related health problems. Exercise intensity will vary depending on your dog’s breed and age. In general, dogs need 30-60 minutes of exercise per day. Exercise activities may include walking, playing fetch, interacting with other dogs, agility games, and swimming.

Mental exercises are just as important as physical ones. Consider purchasing a puzzle, dispensing toys, or teaching new tricks to stimulate and keep your furry friend busy.


Fortunately, a healthy diet and daily exercise can reduce weight-related health problems. Controlling your pet’s weight is a preventative measure that may reduce the risk of developing cancer and help provide your pet with a long, healthy, and happy life.

The Pet Cancer Foundation’s Website Editorial team is comprised of veterinarians, veterinary oncologists, and veterinary technicians, as well as scientific writers and editors who have attained their PhD’s in the life sciences, along with general editors and research assistants. All content found in this section goes through an extensive process with multiple review stages, to ensure this extended resource provides pet families with the most up-to-date information publicly available.

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Last Updated: June 23, 2022

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The Pet Cancer Foundation’s medical resource for pet owners is protected by copyright.

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