In the past the term alano englobed all the types of catch dog,heavier and leaner.Posibly the dogs that the english called spanish bulldog was alanos of the former type.In my opinion the dog more closely relationed (in his origins at least) is the DDB.The modern spanish alano is breeding of catcht dogs of the north of Spain (more exactly Vizcaya-Santander frontier) with an strong boxer influence.In early XX century heavier dogs was employed,but trought the years,the cattlemen learn that a lighter dog can do the same work and crossed with other dogs (the villano have this origin in that concepct,but an step way in lightness).Actually all the tales about "perro de toro" are cheap (and bad) literature.Sorry my english.Greetings from Spain.