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 large dog. The following table illustrates this.
• 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).
• Neutering. 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. See the following section Years versus
Healthy Years for discussion.
• Individual 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.
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