Obesity in Dogs

What is obesity?

Obesity is an accumulation of excess body fat, which leads to excess body weight. We can measure weight on a scale (in pounds or kilograms) to determine if a dog is overweight or obese. Measuring body weight is easier than measuring body fat.

Dogs are considered overweight when they weigh 10% to 20% above their ideal body weight, and considered obese when they weigh more than 20% above their ideal body weight. In North America, obesity is the most common preventable disease in dogs. The 2022 Association for Pet Obesity Prevention survey reports that 59% of dogs (and 61% of cats) are overweight.

What risks are posed by obesity?

Obesity is a chronic inflammatory condition that can shorten a dog’s life and predispose it to diseases like diabetes mellitus, orthopedic conditions, or cancer. Studies show that being even moderately overweight can reduce life expectancy by nearly two years.

In the past, fat stores in the body were considered relatively inactive tissue, simply holding excess energy (Calories) and adding to body mass. However, scientific evidence now reveals that fat tissue is biologically active. Fat cells secrete inflammatory hormones and create oxidative stress on the body’s tissues, which contributes to several diseases. The new approach is to think of obesity as a chronic, low-level inflammatory condition.

Compared to lean or “fit” dogs, overweight and obese dogs develop an increased risk of the following problems:

• Cancer
• Diabetes mellitus
• Heart disease
• Hypertension
• Osteoarthritis and faster degeneration of affected joints
• Urinary bladder stones
• Anesthetic complications

Obesity may also be an indicator of diseases such as hypothyroidism (an underactive thyroid gland) or Cushing’s disease (overactive adrenal glands).

How can I tell if my dog is obese?

The first step in helping an overweight or obese dog is to recognize and acknowledge that there is a problem. Unfortunately, we are inundated with images in the media of overweight dogs, making it challenging to understand what good health and a fit body shape looks like. Your veterinarian and veterinary healthcare team can assist by providing an assessment.

You can assess your dog’s body condition at home by checking how much fat they have covering their ribs and comparing that to the feel of different areas of your hand. Start by feeling the dog’s ribs just behind their front legs.

• If the ribs feel like the flesh covering the back of your hand, your dog has a good body condition.
• If the ribs feel like your knuckles, or stick out like knuckles, your dog may be too thin.
• If the ribs feel more like the fleshy part of the palm of your hand, your dog may be carrying too much weight over the ribcage.

This hand comparison is also a good way to measure weight loss progress between formal weigh-ins at your family veterinary clinic.

Your veterinary healthcare team can calculate an ideal body weight to use as a target. Still, it is essential that they also conduct regular assessments to ensure progress is being made toward an improved body weight and body condition. Most veterinary practices use a body condition scoring system on a scale of 1-5 (where 3 is ideal) or 1-9 (where 4-5 is ideal).

How do I adjust my dog’s meals to help him lose weight?

It is not appropriate to simply reduce the volume of your dog’s current food, because this approach could result in deficiencies of important micronutrients over time. Once you have identified that your dog is overweight or obese, work with your veterinarian and healthcare team to adjust feedings for weight loss. The most efficient way to do this is by using a restricted calorie therapeutic diet, a specific portion, and a specific meal frequency.

"Treats or snacks should comprise no more than 10% of your dog’s daily calorie intake."

There are several commercial kibble and canned veterinary-formulated diets designed for safe weight reduction in dogs. For pet owners who wish to feed a restricted-calorie homemade diet, it is important to work with a veterinary nutritionist who has experience using formulation software so they can customize a balanced recipe.

Once the new food has been selected and specific portions are determined, it is critical that you are consistent with feeding–both portions and meal frequency. It is also important not to go overboard with extra snacks. Treats or snacks should comprise no more than 10% of your dog’s daily calorie intake. For example, if there’s a target of 1,000 Calories (kcal) per day, the dog should have 900 kcal coming from the recommended diet and 100 kcal from recommended treats or snacks.

Monthly weigh-ins are important for successful weight loss and to keep everyone accountable. It is essential to verify weight loss to ensure that it is not too fast or too slow, and to determine when your dog has achieved a healthy body condition. It is also recommended that you incorporate a physical rehabilitation consultation and rehabilitation therapies into the weight loss plan for successful weight loss.

For more tips on reducing your dog’s weight, see the handouts “Creating a Weight Reduction Plan for Dogs” and "Walking Your Dog for Weight Loss".

What happens when my dog reaches the weight-loss goal?

Once ideal body weight and condition have been achieved, it is important to maintain that weight. With guidance and support from your veterinary healthcare team, you can find an appropriate maintenance food, calorie goal, and daily portions for keeping your dog’s lost weight off.

Portion control is critical at this stage to avoid regaining weight, and that applies to both food in the bowl and treats. After so much hard work, a relapse into obesity would be disappointing. Yo-yo weight loss and weight gain are no healthier for dogs than for humans. The benefits of normalizing body weight and condition make the effort well worth it.