Weight on the scales only tells part of the story. Vets use a body condition score, from 1 (very thin) to 9 (obese), where 4 to 5 is ideal. The 2021 AAHA guidelines suggest checking it, along with a muscle condition score, at every vet visit.
Two quick checks
- Feel: you should be able to feel the ribs under a thin layer of fat, like the back of your hand with a flat palm.
- Look: from above there should be a waist behind the ribs, and from the side the tummy should tuck up.
What the scores mean
On AAHA's 9-point scale, 4 corresponds to roughly 15 to 19% body fat and 5 to 20 to 24%. Each step up adds about 5% body fat: a 6 is about 10% overweight, a 7 about 20%, an 8 about 30% and a 9 about 40% or more.
Muscle is scored separately as normal, or mild, moderate or severe loss. AAHA notes a pet can be overweight and still be losing muscle, so the two scores do not replace each other. WSAVA publishes free body and muscle condition charts for dogs and cats.
- 1 to 3: too thin. Ribs and bones show. Please see your vet.
- 4 to 5: ideal.
- 6: a little heavy, about 10% over ideal weight.
- 7: heavy, about 20% over.
- 8 to 9: very heavy, 30 to 40% over.
Each point above 5 is roughly 10% over ideal weight (AAHA). That is how we estimate an ideal weight from a score: current weight divided by one plus that percentage. For a 34 kg dog at score 7, the estimate is about 28 kg.
Cats
Cats are harder to judge by shape, and we do not yet use a score for them. We ask a simple question instead and recommend a vet check if you are unsure.
