The Saarloos Wolfhound is a race of dog shepherd with big psychic qualities that qualify him to take to end salvage missions and rescue. Toward 1923, Leended Saarloos, cook in a line ship and, in their leisure whiles, studious of the wild fauna of their country, it was able to cross a German Shepherd and a wolf. He/she ended up obtaining up to twenty-eight puppies in successive matings. Of these, three were only considered capable to begin the new species. The intention of Saarloos was to create a race in which degenerative symptoms were not appreciated, and getting it became for him a true obsession. Once carried out the crossing, Saarloos received the visit of the Dr. Van Lochium, director of the Biwnengasthuis, a hospital of Amsterdam. This geneticist that investigated for that time about the factor Rhesus (Rh), it supposed that the high modality among the puppies produced it the frequent emparejamientos endogámicos; but the analyses of blood demonstrated that the factor Rhesus didn't exist in the recently created race. Leended Saarloos carried out a selection of characteristic morphological, it was able to go out ahead with thirty or forty copies during the difficult years of the war and it tried to already consolidate the homogeneity gotten. The presence of the first English merchants in the islands was fundamental for the fixation of the character of the Preys Canaries. The Englishmen contributed them the essential sign to differentiate them of the Hispanic remaining preys: their use in the combats. This English contribution has made of the Dog of Prey Canary a singular animal, born to combat with its congenerics.