A study was carried out at the Alfort Veterinary School to apply the concept of sentinel animals to environmental toxicology, associated with pet epidemiology. The recruitment, with owners' consent, of adequate dogs (over 10 kg) in sufficient number, at the School's attending clinics has made it possible to quantify the lead blood level in 125 dogs coming for consultation. Univariate and multivariate linear regressions were used to investigate a potential relationship between lead blood levels and intrinsic parameters relating to the animals themselves as well as to extrinsic factors related to the lifestyle and environment of these dogs, as described by the owners in their answers to our environmental questionnaire. The age of animals, the place where they lived (countryside, city, suburb), the year of construction of their housing were related to variations in lead blood levels, although not significantly because of the limited number of samples. Younger dogs because of similarities in their behavior and higher values of lead blood levels may be worth considering as sentinels for lead poisoning in children, as demonstrated in U S medical literature. This kind of study ought to be repeated on larger samples to obtain more significant results.