The fila brasileiro is descended from the fifteenth-century English Mastiff along with other breeds including bloodhound and bulldog. The fila has excellent tracking abilities, and will not attach its quarry, but will hold it until the hunter arrives. It gets its mastiff appearance because of the pendulous upper lips.
Look at the fila brasileiros appearance and size. The breed is well-boned and has a rectangular structure. The coat is short and smooth, and at the same time, is dense and soft. The Fila is 25 inches to 29 inches and should weigh in at 90 to 110 pounds. The breed may be solid or brindle, but may not be white, mouse gray, patched, dappled or black and tan. The typical colors are fawn, black or brindle. The brindles may have stripes of any intensity. It may or may not have a black mask. White markings on any color should be limited to the chest, tip of the tail and the feet.2
Look for the distinguishing characteristic of the breed. The skin is thick and loose all over the body, but especially at the neck. It forms pronounced dewlaps. In some dogs, the skin will folds will go as far as the chest and abdomen.3
Check for temperament. The fila brasileiro, while a courageous and powerful mastiff, is responsive and pliable with its human family, and makes a very loyal companion. The fila is especially dedicated to its owner and will protect without a moments hesitation. You will not have to teach a fila to protect youhe does this on his ownit is a trait of the fila. The breed is very wary of strangers, and should be socialized at an early age, though with even proper socialization, it not guaranteed that the fila will ever come to accept strangers. At the most, it may show the fila that not everyone is a threat.