We all have heard that to figure your pet’s age in human years you just multiply their age in years by 7. This “fact” was actually conceived as a very effective marketing strategy by a dog food company back in the 1970’s. It sold a lot of product and effectively burned its way into our consciousness to this day. The actual truth of how our pets age is a bit more complicated in comparison to humans.
An average Great Dane grows very quickly in size, reaching maturity around 2 years of age with an average life span of 6-8 years. A Yorkshire Terrier on the other hand, usually reaches maturity in less than 12 months and has a life span that can often exceed 15 years with proper health care. This points to the fact there is a significant variation and rate of aging depending on the breeds. Larger dog breeds age faster and have shorter life spans than smaller dog breeds. A rough comparison between dogs and people suggest that a dog ages the equivalent of 10 human years each of its first 2 years of life, but then aging slows down to 4-8 dog years for every one human year. The aging calculations are considerably different for cats.
First of all, cats live longer than dogs. It is not uncommon for some indoor cats to live up to 19 years old, while the maximum age for an outdoor cat tops out around 8-10 years of age in the best of situations. I have even met a couple of cats that were 24 years old. Cats age faster when they are younger, but this slows down as they get older. At 6 months of age, a female cat can already reproduce. At 1 year of age, a cat’s bones fully stop growing, while this occurs in people around 24 years of age, give or take a few years. So, a 1 year old cat is roughly the age equivalent of a 24 year old person. From this point on, cats age approximately 4 years for every one human year.
Due to their accelerated aging and shorter lifespans, our pets will develop age related chronic diseases faster than humans. Since most pets visit a vet once or twice a year, the comparison would be an adult visiting a family physician only once in roughly 4 years. This makes practicing preventative medicine challenging, particularly for our senior pets that have a higher risk of developing serious illness. Because our pets age so differently than we do, diagnostic lab test, especially blood screenings, are an integral component of your pet’s yearly examination just as they are for us.
To determine your pet’s age in human years and life stage, use the age calculation charts available on my website, doctorblandvet.com.
Dr. Pierre Bland is the owner or “Dr. Bland’s Vet House Calls”, a veterinary house call service. He can be reached at 954 673- 8579 or at doctorblandvet.com