Dog Years and Cat Years
Contrary to popular belief, one dog or cat year does not equal 7 human years. Trying to figure out how old your pet would be if he were human is a bit more complicated than simply multiplying by 7.
With dogs, for example, smaller breeds tend to live longer than larger breeds so they are considered to “age less” every calendar year. Thus, a 5-year-old Chihuahua is “younger than” a 5-year-old Great Dane since the smaller breed will likely live more years. However, smaller breed dogs also tend to mature more quickly in the earlier stages their lives. A 1-year-old small breed dog is “older than” a 1-year-old larger breed dog.
It’s also a bit complicated when it comes to cats. A 6-month-old female kitten is already in its child-bearing stage, which cannot be said for humans. When a cat is 1 year old, its bones stop growing and, in humans, this happens at about 24 years of age.
There is no easy mathematical solution for equating an animal’s chronological age with its “human age” counterpart. You need to consider the animal’s breed and what stage of life he’s in (newborn vs. older age) as well as its size, nutritional habits, general health and living conditions.
If you’d like to try your hand at this, Purina came up with these handy calculators:
Cat Ages: http://www.purina.co.uk/content/your-cat/understanding-your-cat/as-your-cat-ages/your-cat’s-age-in-human-years.
Dog Ages: http://www.purina.co.nz/Home/All+About+Dogs/Living+Together+Dog/Get+More+Out+Of+Life+Dog/Your+Dogs+Age+In+Human+Years.htm