Assessment of body weight, body condition score, and lean body mass is a better indicator of overall health in dogs and cats than body weight alone.1
Although regularly monitoring body weight is a good practice, weight is just one component of a healthy body condition. The variation within breeds, especially mixed breeds of dogs, can make it difficult to pinpoint an ideal weight. Also, body weight can remain stable while fat mass increases and lean body mass declines.
Purina scientists developed and validated a 9-point Body Condition Score (BCS) system for dogs and cats.2,3 The BCS system assesses external body fat and can help estimate a pet’s optimal body weight, regardless of breed or body size.
Independently validated in published peer-reviewed studies and currently recommended by the World Small Animal Veterinary Association, this practical tool to support weight management for dogs and cats is now used by veterinarians worldwide.4-7
Using Purina's 9-point BCS system, the ideal body condition is defined as a visible waist (when viewed from above) and abdominal tuck (side profile), and easily palpated ribs.
An ideal BCS is defined as 4-5 for dogs, and 5 for cats.
Pets with a BCS of 8 or 9 are considered obese.
Evaluating muscle mass, in addition to assessing the body condition score, is important to help account for losses of lean body mass that may occur even in overweight pets.8
Lean body mass includes skeletal muscle, organs, and the skin—essentially all soft tissue except fat. Maintaining lean body mass is important for overall health.9-11 Lean body mass serves as an amino acid reservoir from which dogs and cats can build the proteins that are essential components of every cell, including immune cells, red blood cells, and hormones.
Lean body mass also accounts for 95% of an animal’s metabolic rate (the rate at which they burn calories) and having a higher percent of lean body mass compared to fat, generally increases the basal energy metabolism.12
The World Small Animal Veterinary Association muscle condition scoring system, which has been validated in published, peer-reviewed research, provides a tool to evaluate for loss of muscle mass in dogs and cats.8,13 Based on visual assessment and palpation, muscle mass is rated as normal, or as mild, moderate, or severe muscle loss.