Reference values seem crucial to both veterinary medicine and human medicine. The main critique is that thetheoretical connections between the concepts of reference values, normality, and health are weak. In this paper,we analyze especially one attempt in veterinary medicine to establish such a theoretical connection. We findthat this attempt fails because it is circular. In conclusion, we would postulate that there are two apparent waysforward: to aim for a definition of health not based on the concept of normality, or to develop the concept ofnormality as separate from statistical normality. These goals can be reached with a one health perspective.