Epidemiology: a foundation for dairy production medicine.

Epidemiology in dairy production medicine strives to optimize production through the elimination and control of disease and the implementation of management practices that promote animal health, welfare, productivity, and profitability. Epidemiology in dairy production medicine is a broad discipline that encompasses many inter-related areas of activity. Quantitative epidemiology includes a range of activities, from counting clinical cases to the development of complex hierarchic decision models. Evaluation and interpretation of "tests" applied at various levels of the health management cycle serve as the basis for diagnostic and monitoring systems. Critical evaluation of the published scientific literature in the practice of evidence-based veterinary medicine facilitates the appropriate use of knowledge in support of health management decisions.