The Fila Brasileiro () is a Brazilian breed of large working dog of mastiff type. It is used as a guard dog, for cattle herding and for big-game hunting; it may also be kept as a companion dog or pet. In the eighteenth century, when slavery was still legal in Brazil, the Fila Brasileiro was used to return escaped slaves to their owners. Etymology The verb "filar" in Portuguese literally means "to hold, arrest, grab". So "cão de fila" (fila dog) or "cão de filar" suggests that it is a catch dog, a dog that "bites and does not loosen its grip". A similar name is also found in two Portuguese dog breeds: the Cão de Fila de São Miguel and the extinct Cão de Fila da Terceira. History The Fila Brasileiro is thought to descend from European dogs brought to Brazil during the Colonial period, with little or no influence from indigenous South American dogs from the Pre-Cabraline era. The Fila Brasileiro were bred and raised primarily on large plantations and cattle farms where they originated. In addition to cattle, jaguars, and other animals, these dogs were taught to chase down fugitive slaves. The first written standard of the breed was edited in 1946. The Paulistas were responsible for organizing a planned breeding program and opening a stud book to register dogs. Dr. Paulo Santos Cruz began to systematically breed the Fila Brasileiro and also contributed largely in setting the CAFIB standard, and who now, therefore, has the right to be called the "father" of the Fila Brasileiro. Appearance In Brazil the breed has two main standards imposed by two distinct clubs, the Confederação Brasileira de Cinofilia, affiliated to FCI, and the Clube de Aprimoramento do Fila Brasileiro. The CAFIB standard was constructed based on the ancient phenotype of the breed. But the current CBKC/FCI standard is the best known internationally. The Fila Brasileiro is a breed of mastiff with large bones and loose skin. According to the international breed standard, dogs should stand between at the withers and weigh no less than ; bitches are slightly smaller, standing some and weighing at least . They have a rectangular build and though they are massive, their natural agility is apparent. The head is big and heavy with a deep muzzle. The ears are large, thick, tapered and either droop or fold back exposing the interior, depending on the dog's