The present invention relates to methods and devices for measuring the musculature of animal. In some embodiments, the musculature of the animal is measured using by generating traces of the animal using a flexicurve ruler and comparing the traces to a reference and/or previous traces of the animal. The methods can be used to improve an animal's musculature by evaluating the muscle development of the animal and changing the animal's diet or exercise regime based on the results of the evaluation.