Years (age) and Human Years (age)
There are many tables for converting between dog years
(age) and human years (age). Many of them use a very simple
calculation (e.g. 1 dog year equals 7 human years). The
following converter not only provides much more accurate
information, it identifies the choices that you can make to
help your dog live longer and age more slowly.
Some dogs will live much longer and age much more slowly
than others. Consequently, one might say for one dog that for
each calendar year it ages the equivalent of 10 human years
whereas another dog ages only 5 human years. The key factors
that determine how long a dog will live are:
- Size of dog.
Generally, small dogs live much longer than large dogs. On
average, small dogs have a life span 1.5 times that of a
- Breed. The
breed of dog is a strong indicator of its life expectancy.
In part this is related to the above factor; large breeds
generally have a shorter lifespan than small breeds.
However, even within the same weight category, some breeds
live longer than others. For example, a Doberman
Pinscher can easily reach 15 years of age and sometimes 20
despite the fact that it is a large dog (about 35 kg. or
77 pounds) whereas the smaller Boxer is shorter-lived and
often does not reach 10 years of age.
- Gender: As
in humans, on average females live longer than males. In
the case of dogs, the female generally lives one to two
years longer (depending on the breed).
Neutered dogs tend to live longer than intact dogs. This
is mainly due to a reduced risk of cancer, as cancers of
the sex organs are often related to sex hormones, which
are greatly diminished by neutering. Current research
indicates that the sooner the neutering is done the lower
the risk of these cancers.
- Living conditions.
Dogs which are properly feed and kept, on average,
live longer than those that are not. In extreme cases,
much longer. Important factors are: diet, exercise, living
conditions, and medical attention.
characteristics. Just as some people are born
with a strong constitution, so are some dogs.
Consequently, while one can talk about the expected
lifespan of a dog based on the above factors, individual
dogs will vary somewhat from this.
It is often said that people live 7 times as long as dogs
so each year of a dog's life is equal to 7 years of a human's
life. This is inaccurate for two reasons:
- The longest-lived breeds have an average lifespan which
is double that of the shortest-lived breeds. So one can
only map years after considering the breed and other
factors described above.
- Most breeds (especially the smaller breeds) have a
relatively short childhood compare to people. A small dog
with an expected lifespan of 15 years would be mature
(sexually and physically) within 1 year. A man with an
expected lifespan of 75 years (the current approximate
male life expectancy in developed countries) would have
the equivalent maturity at 15 years of age. Thus the dog
reached maturity in 1/15th of its lifespan whereas the
person was mature in 1/5th (15 years / 75 years) of his
lifespan. Consequently, while one can say that the man is
living 5 times as long as the dog, so each dog year is
equal to 5 human years, the first year of life for the dog
sees the same amount of development as in the first 15 or
so human years. For this reason, an accurate mapping of
dog years to human years needs to consider factors other
than expected lifespan. The following table does this,
considering the different development stages and the rates
at which they are reached (on average) for the different
sizes of dogs.
The above table is based on averages. However, considering
the additional factors (such as breed) discussed on this page
would give a more accurate forecast for individual dogs. The
oldest recorded age for a dog is 27 years.
When asking how long a dog is expected to live, one should
keep in mind the difference between total years and total
healthy years. Some dogs will be healthy and active almost all
their lives, while others may suffer from diseases which
dramatically shorten the period of healthy, active and
productive years. Although one cannot predict the health of a
dog with certainty, one can increase the probability of both
general health and long life through careful selection and
proper care. Your vet can advise on the following
- Breed Health.
Some breeds are generally healthy while others are known
to be prone to certain diseases (e.g. hip dysplasia, brain
tumours, skin allergies). If you have not yet decided on a
specific breed, you may wish to discuss with your vet the
various breeds you are considering and their outlook.
- Breed Lifestyle.
Each of the breeds have been developed with a specific
purpose in mind, be it sheep herding or family pet. The
purpose for which you are using a dog and the way in which
it will be kept should keep this in mind. In general,
'working dogs' need lots of space and exercise; without
this they will suffer greatly mentally and to a certain
extent physically. On the other hand, a 'house dog' used
as a working or outside dog may suffer disease (e.g.
arthritis from cold and wet) and early death if subjected
to severe outside conditions.
- Breeder. Serious
respectable breeders have their dogs carefully and
professionally examined for inherited and other diseases
before considering breeding from them. Consequently,
purchasing a dog from a respected breeder while
likely more expensive initially, can save a lot of
heartache and medical expenses.
- Diet. Although
dogs have different nutritional requirements then people,
like us their health and lifespan will be improved through
a suitable diet, with sufficient but not excessive amounts
of food. A dog's requirements will depend on its age,
breed and lifestyle (e.g. very active dogs need a higher
proportion of carbohydrates than less active dogs).
All dogs require regular exercise (at least several times
a week). The amount and type of exercise will to some
extent depend on the breed and the individual dog. Working
breeds (e.g. dogs breed for herding) generally require
much more physical exercise, not only for their physical
health but also for their mental health. It is possible to
over-exercise a dog (particularly if it is very young or
is elderly or if the weather is very hot) but this is
rare; most dogs (like most dog owners) could use more
exercise rather than less. In addition to physical
exertion, exercise should also involve a certain amount of
mental stimulation. Varying the route of the daily walk,
playing with the dog, training it or giving it tasks to
perform will all provide this.
- Living conditions.
Dogs kept outside with inadequate shelter (from
cold, wind or rain) or in poor living conditions (e.g.
insufficient space, without clean water or in unsanitary
conditions) will not only have a shorter lifespan, but
will also be prone to early illness. That being said, what
is suitable for one dog may not be suitable for another.
For example, certain long-haired dogs have been breed for
very cold conditions while others (such as the
Newfoundland) can easily handle extremely wet and cold
- Medical Attention.
Dogs should have vaccination against the common canine
diseases. In some parts of the world the presence of
certain deadly parasites (e.g. heartworm) require that
dogs receive preventive medication monthly to ensure that
they are not infected. Finally, like people, dogs
periodically require medical treatment for illness or
injury, especially as they get older.