How Long Do Cats Live?

The life expectancy of cats varies by individual, as many factors can affect it, but some generalizations can be made.

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As our cats grow older, it's normal to wonder how long they will live. Via ollie harridge/Flickr
As our cats grow older, it's normal to wonder how long they will live. Via ollie harridge/Flickr

When I was asked to write an article about cat life span, I thought to myself, “That’s a tough question.” There are so many things that can influence a cat’s life span, just as with human longevity. Factors affecting cat life span include breed, sex, being neutered or spayed, diet, home environment, location in the world, access to veterinary care, household income, etc. The list can go on and on!

Research On Cat Life Spans
Surprisingly, there are not too many peer-reviewed, science-based papers that answer the question “How long do cats live?” Most research will examine the survival rate of a specific population of cats that have a certain disease. Other reports review survival after a specific type of surgery was performed. Hopefully, now you can understand why there isn’t a lot of information on this very broad topic: “What is the life span of a cat?”

Too many factors can influence a cat’s life, making it very difficult to conduct research that can account for everything that affects longevity. All that being said, a few scientific reports have examined longevity and mortality of cats.

Many of the more recent studies are from Europe, specifically Sweden and the United Kingdom, where a high percentage of cat owners have pet insurance. You know, once insurance agencies get involved, they will demand data to set premium rates, and age is a big factor that they use.

In a 2014 report from the United Kingdom, the median life span for cats was 14 years. Most cats that died at ages less than 5 suffered from trauma, infectious diseases (bacteria, viruses, parasites) or respiratory disorders. Most cats at or over the age of 5 were likely to have died from kidney disease, a non-specific illness, cancer or an undiagnosed mass disorder. In that same report, there was a direct association between death and body weight. The heavier the cat, the shorter her life.

A Swedish report that tracked 49,450 insured cats from 1999 to 2006 reviewed the deaths. Approximately 6,500 cats died, with Siamese and Persian mortality rates higher than other breeds, but being male or female was not a factor.

Veterinary Advice About Cat Life Spans
Well, what if you just asked your veterinarian “How long do cats live?” As doctors, we hate when we cannot give a straightforward answer to what seems like a simple question. As I searched for information to answer it, I came across many opinions from veterinarians around the world. I will say that the general consensus is that domestic, indoor cats have a life span of 12 to 15 years, while outdoor cats have a much shorter life span of 2 to 3 years.

The oldest cat, according to the Guinness Book of World Records, was a cat named “Crème Puff” who lived in Austin, Texas, until the age of 38! The most recent record holder was a cat named “Tiffany Two,” who was 27 years old this past March and died in May. So, just because your cat is 17, doesn’t mean it’s time to plan for her loss. Remember, age is not a disease!

The American Animal Hospital Association publishes “life stages” guidelines that help both veterinarians and pet owners care for their cats based on age. Once cats reach the age of 11, they are called “seniors.” Geriatric cats are those 15 years and older. Recommendations for geriatric cat care include at least yearly veterinary visits for a complete physical examination, along with routine blood testing for things like kidney disease.

Factors Affecting Life Span
Of all the cats who are diagnosed with kidney disease, 80 percent are over the age of 10. A big problem we face trying to diagnose kidney disease is that the tests are not very sensitive until loss of 75 percent of kidney function occurs. What this means is that if your 12-year-old cat gets a checkup and lab tests, kidney disease will not be found until there’s only one-fourth or less of kidney function left! Luckily, there are newer blood tests that can detect loss of kidney function much sooner. These are undergoing studies now. One major national laboratory has begun to include the test routinely.

It’s not surprising that as the human life span increases, so does that of our cats. Advances in disease prevention like the use of vaccines, modern medical diagnostics and treatments, along with improvements in nutrition, all contribute to increased longevity. One universal fact is that all living things will die, and there is great variability among species and individual members of a species. So, genetic factors play an important role, along with the aforementioned environmental factors.

The Science Of Aging
What happens during aging? Over time, the cells that comprise a living organism undergo changes in their function. They no longer do all of the same work, at the same rate, with the same results. One important aspect of cellular health is antioxidant capability. Chemical reactions that maintain homeostasis (internal stability) lead to the formation of reactive oxygen species or reagents called “free radicals.” These are highly reactive compounds that disrupt the cellular environment. Cells have the ability to neutralize these compounds through scavenging, but as they age, they no longer scavenge free radicals effectively.

In addition to limited free radical scavenging, cells are programmed to die, a process called apoptosis. Genes control programmed cell death and can be “turned on” by a number of factors like hormonal imbalances, infections, exposure to radiation and lack of certain nutrients. As cells of the immune system, nervous system and endocrine (hormone) systems age, loss of organ system function results in their inability to keep things stable (homeostasis), leading to cell death.

Just remember, age is not a disease, and determining if death was “natural” or due to disease is very controversial. There is no consensus among age researches of how to distinguish death due to disease and what we call “the normal aging process.”

Ways To Increase Cat Life Spans
Now that we’ve reviewed some published death rates and what happens to cells during aging, the obvious question is “Can we improve longevity for our beloved cats?” I hate to be cliché, but the things you hear during daytime TV talk shows and read about on Twitter and Facebook about diet and exercise for increasing human life spans are also recommended for cats.

Calorie restriction, in rats and mice, has been found to increase life span. When researchers compared rats with restricted diets to those that were not restricted, the average survival was about 28 percent longer. So, routine play to encourage movement and exercise, and a proper diet as prescribed by the family veterinarian, should help keep your kitty around longer. Well, we all know how difficult it is to keep an exercise and diet routine for us, let alone our cats.

You may think that because we are in the 21st century, surely there’s a pill or something that can improve longevity. Of all the drugs, supplements and vitamins that have been studied, I know of one that shows promise — L-deprenyl. This drug is a central nervous system monoamine oxidase inhibitor. It works by decreasing the breakdown of a neurotransmitter, dopamine, and it also has anti-apoptotic effects. L-deprenyl is used to treat Parkinson’s disease in humans and cognitive dysfunction syndrome in dogs. Most studies evaluating this drug for longevity have been in rats. L-deprenyl increased sexual activity and life span in senior rats. There is one report of its use to determine if longevity could be improved in senior dogs, and it did. But there are side effects.

So the basic generality is that indoor cats live around 15 years, while outdoor cats live around 3 years. Cats who are active, with good body condition and good preventive care should live longer, happier lives.

Article Categories:
Cats · Health and Care

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