The Russian Tracker or Russian Retriever is an extinct breed of domestic dog. It is uncertain when precisely the breed ceased to exist; it could still be found in the late 1800s. The Tracker was of Asiatic Russian origin. It was used for hundreds of years to protect and herd the flocks of the Indo-Aryan people in the wind-beaten, snow-swept Caucasus Mountains.
The Tracker was a large dog, sometimes standing as high as 30 inches (76 cm) at the shoulder and weighing 100 pounds (45 kg) or more. Despite its seemingly cumbersome proportions, it was fast and flexible enough to chase off wolves and other such predators that threatened its sheep. It wore a thick, taffy colored double-coat that protected it from both the harsh weather and the savage wildlife. Aside from its physical prowess, this mountain dog was also blessed with exceptional intellect. It was so wise and capable (legend says) that it could keep himself and its flock alive and well for months on end with no human help.
The breed is related to on some level, and may be synonymous with, the Yellow Russian Retriever, which measured 28 inches (71 cm) and 90 pounds (41 kg).[A] That breed was reputed to be used for tracking wounded deer. The Tracker's closest surviving descendent is the Golden Retriever; however, the Flat-coated Retriever and a few of the Setters are also believed to carry Tracker blood.
^One source takes issue with Mason's inclusion of the breed in his work, and essentially suggests that the facts were mischaracterized or distorted. He claims that Russian mountain dogs are not part of the lineage of Golden Retrievers, although Russian circus dogs might have been.  Another source flatly states that the Russian circus dog/Golden Retriever connection is a "myth."