Question: What is a breed of working dog that originated in Texas in the mid-19th century, Gran Mastín de Borínquen or Blue Lacy ?
Sentence (from "Gran Mastín de Borínquen"): The Gran Mastín de Borinquen, also known as the Puerto Rican Mastiff, Mastín Borincano, Becerillo de Borinquen and Perro Barsino de Hacienda, is the only breed native to the island of Puerto Rico.
Relevant evidence: Yes