Pet Weight Loss Calculator

The NRC recommends feeding overweight dogs and cats at the Resting Energy Requirement (RER) calculated from the animal's target (ideal) body weight, not its current weight. RER at target weight = 70 x (target weight in kg)^0.75. This results in a modest calorie restriction that promotes safe, gradual weight loss of approximately 1-2% of body weight per month.

The American Animal Hospital Association (AAHA) 2021 Nutrition and Weight Management Guidelines recommend a target weight loss rate of 0.5-2% of body weight per month. Faster weight loss (more than 2% per month) increases the risk of muscle loss and hepatic lipidosis in cats. Slower is safer.

Body Condition Score (BCS) is a 9-point scale (or 5-point in some systems) used by veterinarians to assess pet body fatness. BCS 4-5 out of 9 is considered ideal. Each BCS unit above 5 on a 9-point scale corresponds to approximately 10-15% excess body weight. A BCS 7/9 dog needs to lose approximately 15-20% of its current weight.

Yes. The AAHA guidelines and veterinary obesity research consistently show that combining calorie restriction with increased activity produces better outcomes than calorie restriction alone. Start with gentle, low-impact exercise (leash walks for dogs, play for cats) and gradually increase duration as fitness improves.

The AAHA recommends monthly weigh-ins during a weight loss program. If the pet is not losing weight after 4 weeks, reduce daily calories by a further 10%. If the pet is losing more than 2% per month, slightly increase food. Always involve your veterinarian in setting the target weight and reviewing progress.