The aim of the present review is to provide a picture of the current knowledge on animal biomonitoring and on the link between pollution and Public Health. There are various reasons leading to this road: the need of early detection of industrial pollutants, especially micropollutants that have adverse effects in very low concentrations: it is important to disclose the presence of these compounds directly or through certain molecular biomarkers in living organisms rather than in the natural environment, where they are often below the detection threshold; the need to optimize the allocation of resources: some experiences of biomonitoring carried out in wild animals may be useful in the identification of pollution sources; however, biomonitoring of domestic animals appears to be more feasable and effective, because they share with humans the exposure to pollutants. Nowadays, professionals of different disciplines such as doctors and biologists do not share a common set of terms and definitions in animal biomonitoring: this review wants to give a contribution in the consolidation of the current knowledge under a common language.