The Brazilian Mastiff was developed in the South American country of Brazil. They were originally bred for use on large plantations and as cattle dogs. Unfortunately, the Brazilian Mastiff is also sometimes used for dog fighting and is banned in the United Kingdom underneath the Dangerous Dogs Act of 1991.

    Brazilian Mastiffs are a Molosser breed of dog, having large bones and loose skin. Males normally stand between 27-30 inches at the shoulder and weigh in at 100lbs. Females are normally smaller and stand between 24-27 inches and weigh in at 90lbs. They have smooth, short coats, colors range from tans and brindle colors. White should not exceed more than 1/4 of a Brazilian Mastiff's coat and is only permitted on the feet, chest, and tail tips.
    
    It is believed the Brazilian Mastiff was developed largely from the Mastiff, Bulldog, Bloodhound, and the now extinct Fila Terceirense. The Bloodhound blood can be seen in their loose skin, and the presence of the Fila Terceirense can be seen in some animals that still have their distinctive crooked tail. Its size clearly came from that of the Mastiffs, as well as the popular fawn coloring and black mask. The Brazilian Mastiff standard was first written in 1968.

    The Brazilian Mastiff is an excellent guard and cattle dog, however, easily shows aggression to strangers. They bond well with their families, which can include children and other pets. Brazilian Mastiffs are known to play very well with children, and will even take a great deal of "play" as long as they are family. They are well known for their faithfulness to their families, but needs to have an experienced owner. If the owner cannot control their aggression, it can lead to attacks. Their aggression is so well known that they are not even disqualified in the show ring for showing aggression toward the judge. This aggression is what has led to the illegal ownership of Brazilian Mastiffs in certain countries.