The Fila Brasileiro is a Brazilian guard dog that was bred to hunt jaguar and guard livestock. The dog is very large, standing about three feet tall in some cases and weighing up to 200 pounds. Their handlers know them for their extreme faithfulness, with a natural suspiciousness towards strangers. This suspiciousness expresses itself in aggressiveness that the dog doesn't bother to hide when faced with a stranger. This is called "ojeriza" which is Portuguese and means a loathing or sharp aversion of strangers. They can be very fast and, despite their massive frames, can jump very well.
The dog's aggressive nature has made it banned in the United Kingdom. It is only one of four breeds with that distinct dishonor. This is partly because the dog is so aggressive, but also because the breed is sometimes brought into the country to be used in illegal dog fighting activities. One can own a Fila Brasileiro in the United Kingdom; one just needs special permission from the courts.
The dog is very well loved in Brazil where it is known as the national dog. It's characteristics of undying loyalty and fierce protectiveness has engendered a saying in that country that states: "As faithful as a Fila." The same traits that have made it difficult for modern urban environments were a great boon to people in Brazil. It had its hey day when cattle herding, plantation work, and jaguar and bull hunts were activities of the settlers in Brazil. Now, commercialization and more have made it less useful, but still beloved by the Brazilian people.
This large dog has a short lifespan. Of the large dogs, it is probably the one with the shortest lifespan. While Brazilian breeders claim the dog can live up to twelve years, most owners report that it dies within seven to eight years. Whether this is due to how the dogs are maintained outside their native country, is not really known. It is known that the dog has a hereditary predisposition to cancer and other diseases that can shorten its lifespan considerably. This breed does suffer from bloat and can suddenly turn ill. Its stomach can start to twist and torsion and the condition is fatal if not treated immediately by a veterinarian. It's possible that dietary considerations can contribute towards bloat so that the dog should have as natural a diet as possible while still meeting its dietary needs.
In dog shows, judges are warned that the Fila Brasileiro is a naturally aggressive dog and it is not disqualified for showing signs of aggression. The judges are warned not to pet the dog as this can be viewed as a sign of intrusion by the breed. However, even with these guidelines, some Fila Brasileiro are still disqualified if they show too much aggression in the ring.