One of the main goals of veterinary epidemiology is to analyse the determinants of disease, commonly called risk factors. The analysis of such systems is usually based on a pluridisciplinary approach, a planned observation of the natural state, and a judicious use of various methods to analyse the data. Most studies are carried out at the animal level, where the modelling techniques (logistic regression, Cox model) and correspondence analysis have shown complementary interest. Other studies are carried out at the farm level, considering the farm as a cybernetic system. The point of view concept plays a key role in the analysis of this complex reality.