"Dogs' lives are too short. Their only fault, really."
~Agnes Sligh Turnbull

The optimal way to assess longevity and risk factors for mortality is a prospective cohort study, in which a large number of individuals are followed from early in life until death, and extensive data is collected on lifestyle and environmental exposures, clinical laboratory values, disease occurrence, and the circumstances associated with their deaths. Such studies are standard in human epidemiology, but nearly non-existent in veterinary medicine. The first canine study of this kind is the Golden Retriever Lifetime Study (GRLS),¹ run by the Morris Animal Foundation, which promises to be an invaluable source of data about longevity, morbidity, and mortality in this breed. Other efforts, such as the Dog Aging Project, are also under way.²

Sources and limitations of lifespan data

Most of the data we currently have about canine longevity is derived from retrospective analyses of a variety of data sets. Data sources have included veterinary medical college patient data,^3–7 medical records from private practice,^8–10 and pet insurance company records.^11–15 Owner surveys have also been used to investigate mortality and longevity in companion dogs.^16–18 Some studies have even used records from pet cemeteries to investigate lifespan in dogs.^19,20 Each of these sources has their own strengths and limitations.