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The Daily Vet is a blog featuring veterinarians from all walks of life. Every week they will tackle entertaining, interesting, and sometimes difficult topics in the world of animal medicine – all in the hopes that their unique insights and personal experiences will help you to understand your pets.

Health Implications Associated with Pet Obesity

Obesity is a huge problem in both pets and people (pun intended). According to the Association for Pet Obesity Prevention (APOP), greater than 50 percent of pets in the United States are overweight or obese. That’s a remarkable percentage, which works out to approximately 89 million cats and dogs.


Obesity leads to a variety of potentially irreversible health problems, including musculoskeletal system abnormalities, endocrine imbalance, cardiovascular disease, dermatologic abnormalities, cancer, and more.


Obesity is the number one nutritional disease in pets. Yet when I ask pet owners and pet enthusiasts what they think is the number one nutritional disease of dogs and cats, obesity is typically not their answer. Usually, it’s malnutrition, or vitamin or mineral imbalance.


Since commercially available pet food is the diet of choice for most American households, processed foods are extremely influential in creating the obesity epidemic in dogs and cats. Most pet owners live in fear of nutritional imbalances in their pet, so they feed a whole food-based diet made of real meat, vegetables, fruits, and grains like we humans eat. Therefore, these highly processed foods containing ingredients vastly different from those appearing in nature are chosen for most canine and feline companions.


Pet owners are actually creating nutritional imbalances in their pets by feeding excessive amounts of nutritionally complete and balanced foods and treats. No matter how nutritionally complete and balanced the food is, consumption of a calorie surplus ultimately creates an unhealthy state.


So, let’s delve further into the pet health problems to which being overweight or obese contributes.


Musculoskeletal System Abnormalities


Carrying extra weight stresses the musculoskeletal system (joints, ligaments, muscles tendons, etc.), which damages normal tissues and creates inflammation. Arthritis is joint inflammation which, when left unresolved, can lead to degenerative joint disease (DJD), permanent alterations in the cartilage surfaces.


Additionally, overweight pets are more prone to torn ligaments (including cranial cruciate ligament rupture) and intervertebral disc disease (IVDD), where the disks that cushion the backbone malfunction and can even pinch on the spine or nerves.


Endocrine Imbalance


The endocrine system is a complicated network of glands and hormones that regulate the body’s ability to manage normal functions (digestion, immune system response, metabolism, water balance, etc.). Two of the most common endocrine diseases diagnosed in companion animals that are associated with obesity are diabetes and hypothyroidism. Diabetes occurs when the pancreas is unable to produce insulin or release it in sufficient quantities to appropriately regulate blood sugar. Hypothyroidism is an under functioning thyroid gland, which causes metabolism to slow down and leads to a variety of undesirable secondary conditions (weight gain, skin problems, high blood cholesterol, anemia, etc.).


With both diabetes in cats and hypothyroidism in dogs, obesity increases the likelihood that these conditions will occur.


Cardiovascular Disease


The cardiovascular system is comprised of the heart and blood vessels (arteries and veins).Having to supply and drain blood from tissue beyond what the body is structurally prepared for causes the cardiovascular system’s components to work harder at circulating oxygen, nutrients, and white blood cells, while also removing toxins. Ultimately, high blood pressure, lack of circulation to body parts far away from the heart, and heart failure can result from of being overweight or obese.


Dermatologic Abnormalities


Excess flesh can create skin folds. Moisture accumulates between skin folds, which leads to inflammation (dermatitis) and fosters a climate appropriate for the growth of microorganisms (yeast, bacteria, etc.).


Additionally, overweight or obese pets face more of a challenge grooming themselves to maintain a cleaner state of their skin or coat than animals at healthy weight.




Being overweight or obese has a well documented correlation with canine bladder and mammary cancer. The inflammation generated by carrying too much weight promotes an internal environment that is friendly to the development of cancer. Additionally, diets rich in omega 6 fatty acids (such as animal-based fats) promote inflammation and have been linked to cancer cell growth.


The good news is that obesity is completely preventable. To start, we pet owners should restrict the portions our canine and feline companions consume at each meal by 25-33 percent (one quarter to one third). Additionally, we need to consider the inherent nutrient value in feeding our pets a whole-food based diet instead of commercially available processed diets. Thirdly, we must shift our focus from giving food as a reward to instead providing praise, socialization, activity, and environmental enrichment.


fat cat, obese cat, overweight cat, cat diet, cat food

 Skinny the Cat, Pet Obesity … Who is Responsible? from Pet Pause by Dr. B



Dr. Patrick Mahaney

Comments  6

Leave Comment
  • Words to the Wise
    10/09/2012 11:26am

    These are definitely words to the wise.

    With one really round cat in my herd, I worry about many of these problems, especially diabetes.

    So far enticements to exercise have been unsuccessful, but we're still working on it!

  • 10/17/2012 12:08am

    In households that have multiple cats it's definitely important to strive to keep them on the hungry instead of overfed side.
    Getting a cat up and exercising certainly can be more challenging than a dog, but it can be done. Elevating food to a height to which a cat needs to climb, putting dry food into balls that dispense one kibble at a time, using a laser pointer or feather toy are simple get the cats to exercise.
    Thank you for your comments.
    Dr PM

  • And yet...
    10/09/2012 12:33pm

    And yet, Dr. Mahaney, your fellow travelers on this blog, Huston, Tudor, keep pushing processed junk foods containing corn, wheat, and other grains as the main sources of protein, which are a primary cause of a lot of this obesity. The main pushers of these junk foods even have the title of "board certified veterinary nutritionists". If ever there were oxymorons, they are.

  • 10/17/2012 12:11am

    Thank you for your comments.
    Just like with humans, there is not one absolute way to feed our pets.
    I do feel it is important that the pet food industry starts to recognize that they need to recommend pets eat whole foods that are comparable to those recommended for people. After all, http://www.choosemyplate.gov recommends whole foods instead of highly processed versions (which really are the majority of what pets in the US eat.
    Also take note that not every bite that we humans consume based on FDA guidelines must be nutritionally complete and balanced.
    Dr PM

  • 10/13/2012 09:12pm

    Great points. I really think it's time to focus the studies on what is behind this obesity epidemic though. Is it really how much we feed, or WHAT we feed?

    Of course, the dog food companies will never do this kind of research, which might reveal that their products are where the problem is.

  • 10/17/2012 12:13am

    Thank you for your comments.
    I would love to see a population of overweight animals eat a freshly prepared, whole food based high-protein high-fiber low fat diet instead of those that are commercially available as part of a long-term study that follows their weight management and all other aspects of their whole body health.
    Dr PM

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