Dr. Rodney Page, professor of Oncology and director of the CSU Flint Animal Cancer Center, sits with a golden retriever, Winston, in the lobby of the James L. Voss Veterinary Teaching Hospital at Colorado State University. | AP file

This 2012 photo provided by Colorado State University, shows a golden retriever, Louie Mesinger, in his backyard during the summer in 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 retreivers 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. (AP Photo/Colorado State University, Josh Mesinger)

This 2012 photo provided by Colorado State University, shows a golden retriever, Louie Mesinger, taking a rest after swimming and diving in the summer at Holland Lake, in Mont. When Jay Mesinger heard about a dog cancer study seeking purebred golden retriever puppies to track their health for life, he immediately signed up 2-year-old Louie. He and his wife know firsthand the toll that canine cancer can take: Louie is their fourth golden retriever. (AP Photo/Colorado State University/Josh Mesinger)

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 retreivers 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. (AP Photo/Colorado State University, Josh Mesinger)

This December 17, 2012 photo provided by Colorado State University shows Dr. Rodney L. Page, Professor of Oncology and Director of the CSU Animal Cancer Center in the College of Veterinary Medicine, at Colorado State University in Fort Collins, Colo. The Golden Retriever Lifetime Study will be the largest and longest study of dogs ever conducted, said Page, the study's principal investigator. The study will focus on three cancers that can be fatal to the dogs, including bone cancer, lymphoma (cancer of the lymph nodes) and a cancer in the blood vessels called hemangiosarcoma. (AP Photo/Colorado State University, Joe A. Mendoza)