Dogs have become a much loved part of the family, but, unfortunately, a dog’s life span is considerably shorter than that of a human. There’s also quite a bit of variability in life span between dog breeds with some larger breed dogs such as the Great Dane having an average life span of around eight years, while a Chihuahua averages around thirteen years.
What are the factors that determine a dog’s life span?
Dog breed
Some dog breeds are known to live longer than others, probably relating to the genetics of the particular breed. Some breeds that are known to have particularly long life spans including the Miniature Poodle, the Bedlington Terrier, the Chow Chow, the Jack Russell Terrier, and the Whippet, all of whom have average life spans in the thirteen to fourteen year range. In contrast, the Bernese Mountain Dog, Bullmastiff, Irish Wolfhound, and Great Dane have average life spans that are under ten years in length.
Size
In general, larger dogs live longer than their smaller counterparts with small dogs living, on average, one and one half times longer than large dogs. No one is sure why larger dogs lead shorter lives. There’s some thought that it may be due to higher levels a biochemical called IGF-1 which is found in higher amounts in larger dog breeds. Higher IGF-1 levels are though to increase the risk for certain cancers.
Whether the dog is spayed or neutered
Spaying and neutering, particularly if performed at an early age gives a dog certain health advantages including protection against several cancers of the reproductive system, most notably cancer of the ovary, breast, and testicles. Neutering a male dog has also been shown to slightly prolong life in several studies.
Gender
What’s true in the human world also seems to hold up in the dog world. Female dogs live longer than male dogs by a time period of about one and a half years, on average. This effect is even more pronounced when a female dog is spayed at a young age.
The effects of breeding
Dogs that are extensively inbred will, on average, have shorter life spans. Puppies that are the prodigy of similar parents are more likely to express genes for diseases that are common in that particular breed.
The care that a dog is given
A dog that is well cared for and given optimal nutrition and exercise is more likely to live a full life span. As more is learned about dog nutrition and preventative health care for dogs, we should continue to see dogs living longer and healthier lives.
As you can see there are many factors that contribute to the lifespan of a dog, some of which are controllable, while others are genetically determined. Fortunately, there are factors we can control that can help our canine friends live longer lives.
Written by Kristie.Leong.M.D
