page_title: Aging in dogs
section_title: Aging profile
hierarchical_section_title: Aging in dogs / Aging profile
caption_attribution_description: English: Graph of dog age versus equivalent human age, grouped by dog size
context_page_description: Aging in dogs varies from breed to breed, and affects the dog's health and physical ability.
  As with humans, advanced years often bring changes in a dog's ability to hear, see and move about easily. Skin condition, appetite and energy levels often degrade with geriatric age, and medical conditions such as cancer, kidney failure, arthritis, dementia, and joint conditions, and other signs of old age may appear.
  The changes in care often required by an older dog may lead a non-experienced owner to release the animal to a shelter or rescue organization. Non-profit groups have sprung up in response to the growing need for senior dog rescue.
  The aging profile of dogs varies according to their adult size: smaller dogs often live over 15–16 years, medium and large size dogs typically 10 to 13 years, and some giant dog breeds such as mastiffs, often only 7 to 8 years. The latter reach maturity at a slightly older age than smaller breeds—giant breeds becoming adult around two years old compared to the norm of around 13–15 months for other breeds.
context_section_description: They can be summarized into three types:
  Popular myth – It is popularly believed that one dog year equals seven human years. This is inaccurate on two scores, because the first year or two years represent some 18–25 years, and the ratio varies with size and breed.
  One size fits all – Another commonly used system suggests that the first two years equal 10.5 years each, with subsequent years equaling four human years. This is more accurate but still fails to allow for size/breed, which is a significant factor.
  Size/breed specific calculators – These try to factor in the size or breed as well. These are the most accurate types. They typically work either by expected adult weight or by categorizing the dog as "small", "medium", or "large".
  No one formula for dog-to-human age conversion is scientifically agreed on, although within fairly close limits they show great similarities. Researchers suggest that dog age depends on DNA methylation which is epigenetic process. Epigenetic changes occur nonlinear in dogs compared to human.
  As a rough approximation, the human equivalent of a one-year-old dog is between about 10 and 15 years—a one-year-old dog or cat has generally reached its full growth and is sexually mature, although it might still be lanky and need to fill in a more mature musculature, similar to human teenagers. The second year is equivalent to about another 3 to 8 years in terms of physical and mental maturity, and each year thereafter is equivalent to only about 4 or 5 human years.
  Emotional maturity occurs, as with humans, over an extended period of time and in stages. As in other areas, development of giant breeds is slightly delayed compared to other breeds, and, as with humans, there is a difference between adulthood and full maturity (compare humans age 20 and age 40 for example). In all but large breeds, sociosexual interest arises around 6–9 months, becoming emotionally adult around 15–18 months and fully mature around 3–4 years, although as with humans learning and refinement continue thereafter.
  According to the UC Davis Book of Dogs, small-breed dogs (such as small terriers) become geriatric at about 11 years; medium-breed dogs (such as larger spaniels) at 10 years; large-breed dogs (such as German Shepherd Dogs) at 8 years; and giant-breed dogs (such as Great Danes) at 7 years.
caption: Graph of dog age versus equivalent human age, grouped by dog size[3]
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