• The Alaskan sled dog is a mixed breed that has traditionally been bred for endurance, speed and strength. This study included eight Alaskan sled dogs. • Sled dogs are found only in close connection with human populated (especially Arctic) areas and are a good example of a species that is subject to many of the same environmental factors as humans and Arctic wildlife. • One environmental factor of significant importance is mercury present in foods. Mercury is both a naturally occurring element and byproduct of human industries.