A body condition score (BCS) is a number assigned to your pet based on evaluation of fat at a few key locations on their body. A BCS can range from 1 to 9 (though some hospitals use a 1 to 5 scale). A BCS of 1 means an animal is severely underweight, probably in danger of death from starvation. On the opposite side of scale, a BCS of 9 means an animal is severely overweight, covered in fat, and at risk for suffering from arthritis and diabetes to name a few complications of obesity. An ideal BCS is 4-5 out of 9. For every number above 5, your pet is an extra 10 percent overweight.