Epidemiology is the study of the origin, distribution and determinants of animal health-, welfare- and production- related states or events in specified populations and it is an integral component of animal health and veterinary public health. Using the equine species as an example, this module aims to provide students with knowledge and understanding of conceptual bases of veterinary and medical epidemiology and a range of different epidemiological methods used for disease surveillance, outbreak investigation, and observational studies to identify risk factors of disease in both human and animal populations. The importance of identifying the risk factors and applications of epidemiological principles to surveillance and disease control within animal and human populations will be addressed. This module will also give students the opportunity to investigate the major health issues in both human and animal populations and the contribution of epidemiology to other health related disciplines.