the owner. The dog is intelligent, but can be stubborn because of its independence, impulsivity and inattention. To achieve obedience it is highly beneficial to start training at an early age. Siberian Huskies were ranked 77th out of 138 compared breeds for their intelligence by canine psychologist Stanley Coren. However, the rankings in Coren's published work utilized only one of three defined forms of dog intelligence, "Working and Obedience Intelligence", which focused on trainability—a dog's ability to follow direction and commands in a direct context, specifically by trial judges in a controlled course setting. The Siberian Husky's work as a sled dog, with minimal active direction from a driver, and a driver's reliance on the dogs to make their own decisions in poor conditions, utilizes the other two forms, "Instinctive Intelligence" and "Adaptive Intelligence", to a much greater extent. Health A 1999 ASPCA publication shows the average life span of the Siberian Husky is 12 to 14 years. Health issues in the breed are mainly genetic, such as seizures and defects of the eye (juvenile cataracts, corneal dystrophy, canine glaucoma and progressive retinal atrophy) and congenital laryngeal paralysis. Hip dysplasia is not often found in this breed; however, as with many medium or larger-sized canines, it can occur. The Orthopedic Foundation for Animals currently has the Siberian Husky ranked 155th out of a possible 160 breeds at risk for hip dysplasia, with only two percent of tested Siberian Huskies showing dysplasia. Siberian Huskies used for sled racing may also be prone to other ailments, such as gastric disease, bronchitis or bronchopulmonary ailments ("ski asthma"), and gastric erosions or ulcerations. Modern Siberian Huskies registered in the US are almost entirely the descendants of the 1930 Siberia imports and of Leonhard Seppala’s dogs, particularly Togo. The limited number of registered foundational dogs has led to some discussion about their vulnerability to the founder effect. History Prehistoric (prior to 1890s) The Chukotka Sled Dog is considered the progenitor to the Siberian Husky. Developed by the Chukchi people of Russia, Chukotka sled dog teams have been used since prehistoric times to pulls sleds in harsh conditions, such as hunting sea mammals on oceanic pack ice. Origination of Name and Split from Chukotka Sled Dogs (1890s–1930s) From the 1890s to the 1930s, Chukotka sled dogs were actively imported into Alaska, to transport gold miners to the Yukon, first as part of the Klondike Gold Rush,