The Estrela Mountain Dog  (Portuguese: cão de Serra da Estrela) is a large breed of dog from the Estrela Mountains of Portugal bred to guard herds and homesteads. It is 'one of the oldest breeds in the Iberian Peninsula.' The first, tentative, recorded breed standard was published in 1922. This standard only reflected the functional features naturally found in the best dogs of the time, although it did mention having dew claws as reflecting a “perfect” dog. The characteristic hooked tail and turned-back (rosed) ears, which later became part of the official standard, were not mentioned in this preliminary standard.
1922.
1922.