The consummate water dog, the Portuguese Water Dog probably shares some of their ancestry with the Poodle. Their ancestors were herding dogs from the central Asian steppes, either brought to Portugal by way of the Visigoths in the fifth century or by way of the Berbers and then Moors in the eighth century. Once in Portugal, they distinguished themselves through their affinity for water, eventually herding fish into nets, retrieving lost nets or equipment, and serving as a boat-to-boat or boat-to-shore courier.

Later the dogs were part of trawler crews fishing the waters from Portugal to Iceland. The breed is known in its native land as Cao de Agua (pronounced Kown-d’Ahgwa), which means dog of water. They come in a long-haired variety known as the Cao de Agua de Pelo Ondulado and a curly-coated variety known as the Cao de Agua de Pelo Encaradolado. With the demise of traditional fishing methods, the Portuguese fishermen and their dogs began to disappear from the coast in the early twentieth century. The breed was saved largely through the attempts of one man, Dr. Vasco Bensuade, a wealthy shipping magnate. He promoted the breed, and through his efforts, the breed club was reorganized.  After a brief appearance in England in the 1950s, the breed virtually died out there. Around this time, the first PWDs came to America, where they slowly gained a following. Their popularity grew more rapidly and the breed is now a loving family companion.