Obesity is common in our society for humans and our pets. Spring is a good time to consider the impacts of winter accumulation of weight resulting from reduced activity and no change in calorie intake. Many pets gain weight during the winter months and lose some of that extra weight in the summer. Unfortunately, the majority of pets never lose all the extra weight and end up in a yearly cycle that leaves them heavier. As pets age, the extra weight contributes to more joint discomfort, reduced mobility, shorter life span, and a predisposition for other chronic disease problems. 

An estimated 59% of dogs and 61% of cats are overweight or obese. When a pet is 10-20% heavier than their ideal weight they are considered overweight. Those that are over 20% (some say 30%) heavier are obese. In dogs, obesity is considered to be their most common preventable disease. In addition to mobility issues, obesity is associated with health issues like heart problems, hypertension, breathing compromise, diabetes, cancer, and urinary disorders.

Clearly there is an aspect of excess weight and obesity that is related to too much calorie intake and too little physical activity. Complicating this is the fact that when a dog or cat is spayed or neutered, their daily calorie need is reduced because their metabolism is reduced. This means they need less food. Calorie intake should be reduced by 25-30%. Unfortunately, their drive to eat is often increased.

However, it is important to note that obesity for many is more complex than just the calorie count. For example, in dogs a low functioning thyroids (hypothyroidism) or over functioning adrenal glands (Cushing’s disease) can result in obesity. Other contributors to obesity include chronic inflammation and dysbiosis (gut flora imbalance).

The Association for Pet Obesity Prevention (APOP) and other groups are shifting the focus of obesity from blame for overfeeding to a recognition that obesity can be a disease problem. New terminology is emerging like “clinical obesity” to help distinguish pets that are overweight or obese without other disease problems from those that have associated disease problems. An example would be the obese cat with diabetes or the obese dog with heart problems. This terminology helps guide the discussion and approach to obesity toward more detailed diagnostic understanding so that evidence-based therapies can be developed and used.

Understanding how to determine if your pet is obese is important. The body composition score (BCS) is used to evaluate each individual to assess if they are overweight. Basically, the score involves the following: 1) rib check – ideal is a light fat covering of the ribs, 2) waist check – ideal a slight indentation of the waist when viewed from above, and 3) tummy test – ideal is a tuck when viewed from the side. The BCS is sometimes combined with the muscle condition score. Keep in mind that by the time obesity is visible on the outside of the body, the abdomen and chest have already been accumulating fat. This means that the lungs cannot expand as fully as with a normal weight and the heart is working harder. The abdominal organs can be infiltrated with fat compromising their function.

Managing weight is critical for health. It is not always easily done because it can be a complex metabolic issue with numerous contributors. An obvious starting point is to make sure the total calories taken in each day is appropriate. This includes the calories from food and treats. Maintaining a healthy level of daily activity is also important. This is easier to do with dogs than cats but there are options to increase play activity for cats. Manage potential contributors like the thyroid. Low thyroid function is common in dogs and may be a contributor to weight gain. Thyroid levels are easy to measure but sometimes give unclear results. Less than optimal function of the adrenal glands can contribute to inability to effectively reduce inflammation and to balance some of the metabolic processes that keep weight gain in check. Interestingly, increasing attention to the gut flora has revealed a connection between obesity and dysbiosis (imbalanced gut flora) in many species.

If you have a pet that is overweight or obese, contact your veterinarian.

Ron Carsten, DVM, PhD, CVA, CCRT was one of the first veterinarians in Colorado to use the integrative approach, has lectured widely to veterinarians, and has been a pioneer in the therapeutic use of food concentrates to manage clinical problems. He is also the founder of Colorado Animal Rescue (CARE). In addition to his Doctor of Veterinary Medicine, he holds a PhD in Cell and Molecular Biology and is a Certified Veterinary Acupuncturist and Certified Canine Rehabilitation Therapist. He practices integrative veterinary medicine in Glenwood Springs. Dr. Carsten is the 2022 Colorado Veterinary Medical Association Distinguished Service Award recipient.