Evaluating and monitoring body condition in canine athletes is critically important. Athletic dogs can markedly increase their metabolic rates during exercise, are often in negative energy balance, and can quickly lose body condition. Existing body condition scoring (BCS) systems were not developed with the canine athlete in mind; they were developed using dogs in stable body condition and are only validated for quantifying relative differences in body fat. This proposed study will develop a new BCS system that will better allow canine and veterinary professionals to estimate both fat and muscle loss in dogs. The results of this study will benefit military working dogs, sled dogs, field trial dogs, and any other working dogs through accurate assessment of the amount of metabolic reserve in these dogs and the changes in metabolic reserve resulting from exercise.