The Henneke Chart is a professional and clinical method of visually assessing an equine's physical condition. Knowing this body scoring system and how to apply it in the field is important. In a court of law, you will be able to provide an accurate account of physical condition, as opposed to a simple statement of "thin" or "emaciated". Any horse that scores under a "3" is in serious condition and will require immediate attention, special feeding and rehabilitation (Rehabilitating A Starved Horse).
The Equine Research Centre
The Horse Interactive