Obesity, Body Condition, and Weight Management
Assessment
Use body condition score (BCS) on a 9-point scale (5 = ideal) and a separate muscle condition score. Weigh patients at every visit and calculate percent overweight. Obesity is a disease, not a cosmetic issue, and predisposes to diabetes, osteoarthritis, and shortened lifespan.
Weight-loss planning
- Determine ideal weight from BCS and historical weight.
- Calculate RER at ideal weight.
- Use a weight-loss factor (often ~0.8 x RER at ideal weight, adjusted to actual loss rate).
- Choose a therapeutic weight-loss diet with adequate protein and micronutrients.
- Recheck every 2-4 weeks; target ~1-2% body weight loss per week in dogs and ~0.5-1% in cats.
Traps
- Too-rapid weight loss in cats risks hepatic lipidosis; avoid severe caloric restriction.
- Treats and table food are often omitted from calculations; account for all calories.
- Weight-loss diets are not interchangeable with maintenance diets; nutrient dilution matters.
- Exercise and behavior modification are part of the plan.
Worked example
A 30 kg dog at BCS 8/9 with ideal weight ~24 kg: RER at ideal = 70 x 24^0.75 = 70 x 10.84 = 759 kcal/day. At 0.8 x RER, feed ~607 kcal/day. If the diet is 3200 kcal/kg, that is ~0.19 kg/day.