Fila Brasileiro Of all breeds, Fila Brasileiros have the most extreme aversion to strangers. They need extensive exposure to friendly people so they learn to recognize the normal behaviors of "good guys." Then they can recognize the difference when someone acts abnormally. Without extensive socialization, they may be suspicious of everyone, and in such a powerful and determined dog, this can be dangerous. Fila Brasileiros may try to protect their own children from other children, which could lead to tragedy if kids are simply roughhousing and your Fila Brasileiro decides to stop it.