The Moscow Water Dog, also known as the Moscow Diver, Moscow Retriever or Moskovsky Vodolaz, is a little-known dog breed derived from the Newfoundland, Caucasian Ovcharka (Caucasian Shepherd) and East European Shepherd. It is now extinct, but was used in the development of the Russian Black Terrier. The Moscow Water Dog was produced only by the Red Star Kennels, the state operated organization chartered to provide working dogs for the armed services.
After World War II, there were very few working dogs in the Soviet Union as many had been killed during the war. Some were imported but there were not enough to establish a dedicated breeding programme for a specific breed. The Central Military School of Working Dogs (the Red Star Kennels), under the command of Colonel G. P. Medvedev began working on developing a number of their own specialised breeds by crossing the available stock. A few breeds were established including the Moscow Newfoundland, a cross of German Shepherd Dog and Newfoundland; the Moscow Great Dane, using German Shepherd and Great Dane; the Brudasty Hound, which was an Airedale Terrier and Russian Hound mix; the Moscow Watchdog, a combination of St. Bernard and Caucasian Ovcharka; and the Moscow Water Dog. The most successful breed to come out of the programme was the Russian Black Terrier, which gained international recognition in 1984; it derived from a combination of 14 different breeds including the Moscow Water Dog in the later stages of its development.
Moscow Water Dogs were bred in Krasnaya Zvezda, Belarus, by interbreeding Newfoundland males with East European Shepherd and Caucasian Ovcharka females, and by mating the offspring with each other. They were developed as a water rescue/lifesaving dog, but according to O. Krasnovskaya, "That was not a good idea as [they] were not willing to save drowning people, but mostly were looking to bite them so this breed was never developed".