The present invention is related to the medical science or the veterinary field, more specifically with the detection, measurement or recording with diagnostic purpose, and in particular it provides an apparatus for the measurement of the angle of the keel and the length of the tarsus in birds for the purpose of evaluating its corporal condition, that comprises: a first elongated piece having a first straight portion; a second elongated piece having a second straight portion; and an axis of rotation of the first piece with respect to the second piece; wherein one of said first and second pieces presents a scale for measuring the length in its corresponding straight portion; and wherein one of said first and second pieces presents a scale for measuring the angle formed between said first and second pieces.
