Livestock production has been characterized by the intensification and specialization of production leading to larger farms and, hence, to fewer farmers per animal. Thus, the animal-to-stockman ratio is increasing and the available time for monitoring an individual animal is reducing. In the same time period, the focus in the veterinary profession has shifted from treatment of acutely diseased animals to more proactive management, which includes the use of epidemiological tools to identify risk factors for animal health, welfare and production. As part of a modern herd management, reliable data on animal health are provided e.g. by routine and standardized testing of animals for the presence of disease. For this, traditional and increasingly sophisticated diagnostic tools are available. Recently, farmers have increasingly been using sensor technologies, allowing continuous and automated health monitoring of livestock. This aims in establishing an early warning system to optimize herd health management and fostering decision making.