Native to the island of Puerto Rico, the mighty Borincano was developed from local working dogs and European mastiffs brought by the Spanish colonial forces, such as the Mastin Espanol, Dogue de Bordeaux and the Bloodhound, among others. Through numerous crossings, both planned and accidental, as well as the introduction of various South-American breeds, the Puertorican Mastiff evolved into an impressive and fierce Molosser, commonly employed as a war dog in conflicts between the Spaniards and the native Carribean Indians, as well as a slave retriever. It also proved to be an excellent guardian and farm dog.
Nearing extinction, it was revived in the 1970's by a group of dedicated enthusiasts, collecting the surviving examples from rural areas of the country and employing outcrosses such as the Presa Canario, English Mastiff, Dogo Argentino, Fila Brasileiro and other breeds in an effort to broaden the gene pool and bring up the numbers of the Borincano. The Puertorican Mastiff is very rare today, although there has been an increase in interest reported in recent years. However, due to its popularity as a fighting dog, many modern strains are heavily "enriched" with the blood of the American Pit Bull Terrier and the American Bulldog, relegating the Borincano to the status of yet another bandogge, without a clearly set type.
Apart from being a capable fighting dog, this is also an excellent property guardian and family companion, fairly easy to train and loving of its master and family, but broad socialization and proper training are necessary to help control the breed's dog-aggressive nature. Quite massive and very powerful, the Borincano is a strong and agile Molosser. Depending on the bloodline and type within the breed, some examples are fairly heavy and tall, while others are smaller and leaner, with all Borincanos being very athletic, well-boned and muscular.
The head is large and broad, with powerful jaws, strong muzzle and reasonably loose lips. While a black nose is valued by the breed purists, many fighting dogs can have brown, blue, red and even pink noses. The ears are usually cropped, but unaltered specimens are commonly seen too. Broad-shouldered and wide-chested, this is an impressive animal, regardless of type.
The dense short coat is preferred in shades of red, brown, black and brindle, with small white markings permissible on the chest and feet, although fawn, blue, grey, particoloured and even uniform white dogs can be encountered.
Average height is around 26 inches, but smaller examples exist as well.