The Rafeiro do Alentejo or Alentejo Mastiff, also called the Portuguese Mastiff, is a breed of dog that originated in Portugal. The Rafeiro do Alentejo is of the livestock guardian dog type, and the name refers to its area of origin, Alentejo, in south-central Portugal. The word rafeiro means Mixed-breed dog in Portuguese.
Rafeiro do Alentejo are of the very ancient molosser Dog type that migrated with humans from Central Asia. When the dogs arrived in the Iberian Peninsula is not known; they may have come with nomads sometime in prehistory or have been brought by the Romans when they ruled the area thousands of years ago. It is often supposed that the breed is related to the Tibetan Mastiff, but no proof of this exists. Perhaps in the future, DNA evidence will prove when the dogs arrived and what their ancestry is, but for now there is no proof, only legends, guesswork, and speculation.What is known is that this breed and the ancient types from which it descended have been used to move sheep from mountains in northern Portugal to the plateau of Alentejo and back to the mountain. Due to changes in agriculture and livestock raising, and the elimination of large predators, the breed ceased to have economic use and began to decline. Animal fancy, however, have been able to keep the breed alive, although, in Portugal, it is still considered "vulnerable". Today the Rafeiro do Alentejo is most often kept as a Companion dog and guard dog.The Rafeiro do Alentejo (Alentejo Mastiff) is recognised by the Fédération Cynologique Internationale in Group 2, Section 2.2 Mastiffs, Mountain Type, Portugal (breed number 96). Other Portuguese breeds in Section 2.2 include the Cão da Serra da Estrela (number 173) and the Cão de Castro Laboreiro, number 150. The Associação Dos Criadores Do Rafeiro Do Alentejo is the official breed club for the Rafeiro do Alentejo in Portugal. Rafeiro do Alentejo are now included in the Foundation Stock Service of the American Kennel Club (as the Rafeiro do Alentejo) and fully recognised by the United Kennel Club in the United States, in the Guardian Dog Group (as the Alentejo Mastiff). It may also be sold by commercial breeders under the Rafeiro do Alentejo name or any of the various translations and English versions of the name, with registration by minor kennel clubs that require little to no breed verification for registration or listed by internet-based dog registry businesses where it is promoted as a Rare breed for those seeking a unique pet.