A Dog's Age

Using 'a dog's age' to indicate a lapse of time, as in "I haven't seen you in a dog's age!" is an expression that's been around since the mid-1800s. The origin is lost in the mists of time. I guess dogs are supposed to have a very long life, which may or may not be true, depending on circumstances.

So, what is a dog's age anyway? With people, most of us are on familiar ground. Approximating age gives us critical clues and we're pretty astute when it comes to making some assumptions when we know an approximate age. We can tell a child from an adult, or a young adult from an elderly person, and by refining our information, we can hone our generalizations even further. A child could be an infant, a toddler or an adolescent. An adult might be a 20- something or a 50-something.

We also know, from our own life experiences, there are typical age-related parameters for humans to achieve skills or behaviors, such as walk and talk, drive a car, drink in a bar, bear children or enjoy the fruits of lifetime labors in retirement.

When it comes to animals, though, few of us are that closely attuned to their developmental stages. Most of us can identify a puppy or kitten, recognize an adult or see the signs of age in a very old pet, yet most of us probably can't say when puppies or kittens are weaned, when they reach the age of reproduction, when they are middleaged or when to expect the physical signs of old age.

In order to simplify the calculation of a dog's age, myth has it that one human year roughly equates to seven years for a dog, or for a cat for that matter. Although incorrectly skewed by this formula, a pet's age and how it relates to our own, is still one of the most important bits of information we note about animals. Usually, my second question when meeting a new dog - after discerning gender - is to determine the pet's age.

The seven-year ration might be reasonably accurate in a pet's middle age, but it has been proved to be misleading and inaccurate for the beginning and end of a pet's lifespan. For instance, at 12 months, a dog is fully grown and sexually mature. Cats spend a relatively small proportion of their lives in an immature stage. Within their first year, both dogs and cats are capable of reproducing; obviously, a 7-year old child is not. An average house cat lives 15 years, or 105 in human years using the 7-1 ratio. But there are a lot more 15-year old cats, as well as dogs, around than 105-year old people.

As for the longevity of our pets, age is only a chronological measure; it fails to take other factors into consideration, such as small dogs generally living longer than large dogs. On average, small dogs have a life span 1.5 times that of a large dog. The breed of a dog also has a strong influence on the life expectancy, due to physical and medical issues that are associated with certain breeds, regardless of size. As with their humans, females tend to live 1-2 years longer than the male.

Neutered or spayed animals live longer than intact animals. Neutering greatly reduces the risk of cancer and spaying either a dog or cat eliminates the physical demands of pregnancy and giving birth. Pets that are well cared for, properly fed, housed and maintained live longer than those who are not.

As with people, some pets are born with good genes. Some pets will be healthy all their lives, while others, in spite of the best of care, can have problems which shorten the period of their healthy and active years. In order to maximize the probability of good health, pet owners can take some factors into consideration.

Some breeds are known to be predisposed to certain diseases such as hip dysplasia, allergies or tumors. Mixed breeds have a reputation for "hybrid vigor," but no one really knows. Each breed of dog, at some point, was developed for a specific purpose, and some breeds require more mental and physical stimulation than others. Matching these needs with your ability to provide them is critical for maximum pet health.

Getting a dog from a reputable breeder who certifies and screens their dogs can minimize unforeseen health problems, but even this is no guarantee. Any pet's life will be improved with a quality diet, regular exercise, good living conditions and periodic medical check ups, particularly as they age.

There are several sources for determining the pet-to-human age conversions. The above chart provides a rough idea of how our canine and feline friends age compared to the way we do. I

Jan Jaeger is owner of Geronimo's, Ltd., Nantucket's year round pet supply shop, Cold Noses downtown pet boutique and is a member of DWAA and CWA (Dog and Cat Writer's Associations of America). Her pets at home are Junior, a Chesapeake Bay Retriever, kitties Mr. Fish, Retd. and Priscilla. At the shop are Mr. Chips, Flower bunny and three budgies.

Dog Years = Human Years
1 year	15 years
2 years	24 years
4 years	32 years
7 years	45 years
10 years	56 years
15 years	76 years
20 years	98 years

Cat Years = Human Years
1 year	15 years
2 years	24 years
5 years	36 years
7 years	45 years
12 years	64 years
15 years	76 years
21 years	100 years