Vet's Note: Fat or Fit? Don't Let the Fluff Fool You
Stop using "it's just fluff" as an excuse — learn to tell whether your pet is muscular or overweight.
Vets are often asked: "My dog weighs 12 kg — is that fat?" "My cat is 4 kg now — time for a diet?"
These questions don't give enough information. We also need breed, age, body shape, muscle mass, physiological and health status. A 12 kg Corgi and a 12 kg Maltese, or a 2 kg puppy and a 2 kg adult, are completely different situations.
Why learn to assess body condition?
Most pets lack self-control and eat whatever we give them, and their coat hides their true shape. If we can't assess body condition we easily let them become obese — a risk factor for many diseases: osteoarthritis, diabetes, cardiovascular and respiratory disease, even anaesthetic risk.
Vets assess body condition and muscle mass to understand a patient's nutritional status; owners who can do the same will notice gradual weight loss early and seek help before an underlying disease advances.
How should nutritional status be assessed?
Because breeds and frame sizes differ, body weight (BW) alone isn't enough; body condition and muscle mass matter more. To communicate, track, record and assess these, two indices were created: Body Condition Score (BCS) and Muscle Condition Score (MCS). Learning both is very helpful for tracking your pet's nutrition.
What is BCS?
BCS grades an animal's body condition on a 9-point scale by palpation and appearance: 1 is emaciated, 9 obese, and 5 ideal.
At the ideal score (5/9) the waist is visible, and when you feel the ribs, hips and spine there is a light covering of fat but the bones can still be felt with slight pressure. A dog or cat with no visible waist, or bones you can't feel through fat, is overweight. Don't believe "it's just fluff" — use the charts below to see through the coat, and catch early weight loss too.
What is MCS?
This is more specialised and usually done by a vet. MCS evaluates muscle mass by observation and palpation of the head, scapulae, either side of the spine and the ilium; the commonest method is pressing the muscle beside the spine to feel its condition. MCS is graded as normal, mild, moderate or severe muscle loss. Notably, even animals scored overweight (BCS > 5/9) can show muscle loss — the equivalent of "skinny fat" in humans — so body condition and muscle condition must be assessed together.
How to help your pet keep a healthy shape
For dogs and cats, preventing obesity and maintaining an ideal condition matters more than dieting after the fact. Build a sensible feeding plan, choose animal-protein foods that supply amino acids matched to their needs, avoid excess unnecessary nutrients that turn into fat, and add appropriate exercise — that is the only reliable way to keep them in shape. (A note from the clinic: dogs that lose mobility to arthritis or other causes often lose muscle for lack of exercise, become even less able to move, and enter a vicious cycle. Support them with suitable exercise or rehabilitation and diet, stay alert to falling muscle mass, and seek veterinary help early.)
References
- Baldwin K, et al. AAHA Nutritional Assessment Guidelines for Dogs and Cats. J Am Anim Hosp Assoc. 2010;46(4):285–96.
- Brooks D, et al. 2014 AAHA Weight Management Guidelines for Dogs and Cats. J Am Anim Hosp Assoc 2014;50:1–11.
- Cline MG, et al. 2021 AAHA Nutrition and Weight Management Guidelines for Dogs and Cats. J Am Anim Hosp Assoc. 2021;57(4):153-178.
