Practice Scenario

Meet Molly, an obese, but otherwise healthy, adult, large-breed dog.

Get to know MOLLY

A 6-year-old, spayed female Labrador Retriever

  • Molly presents for routine physical examination and vaccinations.
  • Molly eats “a scoop” of dry adult dog food twice daily. The owners give Molly “a handful” of treats every day and, occasionally, table scraps.
  • Molly has a body condition score of 8/9, weighs 35 kg (77 pounds), and has normal muscle mass.
  • She appears otherwise healthy and is bright and alert on exam.

MER Calculator for Dogs

This interactive tool has been designed to help you with nutritional recommendations. Enter your patient's age group, weight, body condition score (BCS), and dietary goals (maintain or lose weight) to reveal estimated ideal weight if pet were in ideal BCS, and estimated daily caloric needs (maintenance energy requirements, or MER).

*Required Fields
Age Group *

Estimated Age of Reaching Senior Status
Breed Size: Age (Years)
Toy/Small breeds: 8+ years
Medium breeds: 7+ years
Large/Giant breeds: 6+ years

Purina Body Condition System for Dogs
Weight Goal *
If a goal of "maintain weight" is selected for a pet with a BCS of 6 or 7, slow weight loss could occur since MER will be based on a lower body weight. However, selecting "lose weight" as the goal will provide greater calorie restriction, which will facilitate faster weight loss. If a pet is underweight, selecting "maintain weight" should encourage slow weight gain since MER will be based on a higher body weight. However, desired weight gain may not occur until contributing conditions are identified and managed, especially in pets with a BCS of 1 or 2.

Related Tools and Content:

MER Calculator for Cats

Using your patient’s age group with current weight and body condition score, this feeding calculator will provide estimated daily caloric needs to reach or maintain ideal body condition.

View Tool 1 min to 5 min