Epidemiology is defined as the study of the distribution and determinants of disease within populations. In addition to the requirements for disease surveillance, epidemiologic methods have numerous applications in laboratory animal science and can reveal important insights into the multifactoral mechanisms of disease, thereby aiding in the design of optimized intervention strategies. Observational approaches to data collection can be used to quantify the role of causal factors under natural circumstances, complementing the value of experimental studies in this field. The meaning and appropriate use of standard measures of disease frequency and exposure-disease relationships are reviewed, along with explanations of bias and confounding. Recommendations for reporting the methods and findings from this type of work in comparative medicine literature are presented. Aspects of model-based approaches to data analysis are introduced, offering further opportunities for gaining needed information from epidemiologic study of problems in laboratory animal medicine and management.