Longest study of dog cancer ever conducted

This summer 2012 photo provided by Colorado State University, shows a golden retriever, Louie Mesinger, resting on a trail during a hike outside of Boulder, Colo. The Golden Retriever Lifetime Study will be the largest and longest study of dogs ever conducted. For Louie and 2,999 other purebred golden retrievers who are chosen over the next two years, their lives, usually a 10-to-14-year life span, will be tracked for genetic, nutritional and environmental risks to help scientists and veterinarians find ways to prevent canine cancer.

Credit: AP Photo/Colorado State University/Josh Mesinger