Exceptional longevity in pet dogs is accompanied by cancer resistance and delayed onset of major diseases.

To characterize extreme aged pet dogs as a first step in developing an animal model of exceptional longevity, we constructed lifetime medical histories for 345 Rottweiler dogs using information collected from owners and veterinarians. Extreme aged dogs (alive at the 95th percentile age at death for the study population, > or =13.3 years) were compared with a usual longevity group (9-10 years). Exceptional longevity in Rottweiler dogs was accompanied by a significant delay in the onset of major life-threatening diseases; 76% of extreme aged dogs remained free of all major diseases during the first 9 years of life. Only 19% of extreme aged dogs died of cancer versus 82% of dogs with usual longevity (p <.0001). The reduction in cancer mortality in oldest-old pet dogs mimics that seen in human centenarians and provides strong rationale for using this animal model to study comparative mechanisms of cancer resistance in the extreme aged.