Ask your Vet About your pet’s Body Condition Score — BCS. The body condition score looks at the amount of fat on a cat or dog’s frame relative to his overall size. If he is too fat, ask your vet what you can do to help him loose weight. If he is too thin, ask for recommendations to address this issue. Every dog and cat should have a wellness checkup at least once a year.Preventative medicine is the key to goo health.