This post is sponsored by Hill’s. I am being compensated for helping spread the word about Hill’s Science Diet for Cats, but I only shares information I feel is relevant to my readers. Hill’s Pet Nutrition, Inc. is not responsible for the content of this article.
For an old fogey 16-year-old kitty, Seren-Kitty is remarkably well preserved. Siamese as a breed tend to have a longer cat life expectancy, and the average age of cats has increased to mid-teens. But it’s not unusual for cat longevity to reach the early twenties and beyond. With the exception of a recent URI, she’s never been sick and enjoys clean teeth, good appetite, normal litter-ary habits, sound heart and no lumps or bumps.
Seren now has a few white hairs surrounding her eyelids, made visible by the dark mask. And she’s got some arthritis so she doesn’t leap as high any more. A couple of her claws have thickened and require more frequent trims since she has trouble pulling them in (she “clicks” when she walks on hard surfaces). But keeping the dog in line seems to keep her very happy and engaged in life! I figured in “human years” she’d be around 75-80. You can find out your pet’s age with this neato cat age calculator.
HOW OLD IS “OLD?”
What is considered “old” for a cat? Those who follow this blog know I spent a couple of years researching and writing about aging pets (including Complete Care for Your Aging Cat) and wanted to share with you some of what I learned from talking with over a hundred veterinary experts. The question of what is old is complicated by the impact of genetics, environment, and individual characteristics. Consider human beings: one person may act, look and feel “old” at 65 while another 65-year-old remains an active athlete with a youthful attitude and appearance. The same is true for our cats.
“I think that actually varies a lot, and it’s getting older every year,” says Rhonda Schulman, DVM, an internist at the University of Illinois. “It used to be that eight was the major cutoff for the cat that was geriatric. Now we’re moving to the point that’s a prolonged middle age.” According to Guinness World Records, the oldest cat on record was Creme Puff owned by Jake Perry of Austin, Texas. Cream Puff was born August 3, 1967 and still living at the age of 37 in 2004.
A good definition of old age for an animal is the last 25 percent of their lifespan, says Sarah K. Abood, DVM, a clinical nutritionist at Michigan State University. However, since we can’t predict what an individual cat’s lifespan will be, the beginning of old age is a bit arbitrary. Certain families of cats may be longer lived than others, in the same way that some human families enjoy a much greater longevity than others. The lifespan of your cat’s parents and grandparents is a good predictor of how long you can expect your cat to live. People who share their lives with pedigreed cats may be able to access this information through the cat’s breeder.
Longevity of unknown heritage cats are much more difficult to predict. Even when felines are “part” Siamese or Persian, for example, these felines may inherit the very worst, or the very best, from the parents. When all is said and done, one should expect the random-bred cat-next-door kitty to be neither more nor less healthy than their pedigreed ancestors—as long as they all receive the same level of care and attention.
Here’s some perspective comparing cat age to human age. “The World Health Organization says that middle-aged folks are 45 to 59 years of age and elderly is 60 to 74. They considered aged as being over 75,” says Debbie Davenport, DVM, an internist with Hill’s Pet Nutrition. “If you look at cats of seven years of age as being senior, a parallel in human years would be about 51 years,” she says. A cat at 10 to 12 years of age would be equivalent to a 70-year-old human. You can check out human aging stats here.
IS AGE 7 THE MAGIC NUMBER?
I have to be honest here. While many dogs truly could be considered “mature” at age 7, healthy cats tend to age much more gracefully. Aging and longevity is so individualized, your cat may not be ready for a diet change until she’s 9 or 10. But since no pet food company has a crystal ball to pinpoint the EXACT time for a change, most recommend using the 7-year benchmark to transition cats and dogs to a mature formulation that helps reduce age related health challenges, like potential kidney issues (a BIG problem in aging felines). Today cats aged 7-10 are considered “mature adults” while 10+ are considered “seniors.”
What kinds of aging changes can you expect? Some are more obvious–like Seren’s white hairs, thickened claws and loss of hearing. But what about her “innards?” While it’s clear a kitten shouldn’t eat the same food as an adult, what’s the big deal with lifestage food choices once the cat’s a senior? Here’s the deal–age changes the way cats perceive–and use–nutrition. Responsible pet food companies research these changes and seek to provide formulations that address changing needs.
AGING KITTY TASTE
Changes in flavor perception are thought to reflect those experienced by aging humans, says Nancy E. Rawson, Ph.D., of the Monel Chemical Senses Center, a nonprofit research institute in Philadelphia dedicated to research in the fields of taste, smell, chemical irritation and nutrition. “But as a carnivore, the feline’s senses of taste and smell are quite distinct from those of the human, and responses to age-associated changes may differ,” says Dr. Rawson.
Cats aren’t able to detect carbohydrate sweeteners (dogs do! so beware the Halloween candy dangers to come!) Cats instead taste and seem to prefer meaty flavors described by people as “sweet.” Detection of meaty, salty and sour flavors doesn’t seem to be affected by age. Bitter tastes are more sensitive to aging changes.
Chemical irritations and “mouth feel” influence how well the cat likes or dislikes a flavor. Pet food companies have whole groups of scientists studying exactly what makes kitty belly up to the bowl, or snub it. Mouth feel can be influenced by changes in saliva content, for example, caused by dehydration that commonly develops in aged cats.
Disease or medication can reduce or increase the sensitivity of the mouth and tongue, and alterations in taste (and smell) can remain even after the disease is cured and the medicine is stopped. Dental disease creates a hypersensitive mouth, interferes with chewing ability, and produces unpleasant tastes and odors that prompt the cat to refuse certain foods. Warming foods increases the volatility of tastes and scents to make them more intense and appealing to the aging cat’s palate.
OLD CAT SMELL SENSE
Scent is very important for cats, but few studies have documented exactly what happens to its acuity in relation to age. Cats do lose smelling sense the older they get, but nobody knows the amount due to changes of aging compared to lifetime damage, says Lawrence Myers, DVM, PhD, associate professor of animal behavior, physiology and medicine at Auburn University. “We’re just starting to get a handle on how much the vomeronasal organ contributes to the total scent picture for dogs and cats,” he says. The vomeronasal, or Jacobson’s, organ is in the roof of the mouth between the soft palate and nasal passages and is thought to be important in the detection of pheromones, chemicals primarily involved in prompting sexual behaviors.
Age-related losses in the sense of smell result from changes in the anatomy—scent cells aren’t replaced as often—and at the molecular level when existing nerve cells and “messenger” molecules in the nose become less sensitive. Reduce salivation or altered nasal mucus composition also impact the way odor chemicals are dissolved and detected.
“We did a study a number of years ago and published it in the annals of the New York Academy of Sciences that dealt with the lack of the sense of smell in the cat, and the influence of food intake,” says Dr. Myers. “A complete loss of vomeronasal as well as olfactory nerve caused the cats not to eat at all. It seems as if the sense of smell gives them some sort of cue that it’s edible,” he says.
OLD CAT DIGESTIVE CHANGES
The digestive system includes the mouth, teeth, stomach, intestines, pancreas and liver. It processes nutrition and eliminates waste. One of the greatest digestion-related problems of aging cats is obesity, or “over-nutrition.” Older cats don’t exercise as much, and their metabolism slows down, so they gain more weight.
However, because cats are true carnivores and use protein as a source for energy, if they don’t eat enough, they’ll lose weight as they age. Cats may gain weight up to age ten, but then lose as they have less ability to digest protein and fat. In fact, weight loss particularly of lean muscle, tends to occur in cats at about two to two-and-a-half years prior to their death from age-related diseases, says Joe Wakshlag, DVM, assistant professor of clinical nutrition at Cornell University. He says studies in otherwise normal adult cats indicate that increasing dietary protein by 35 percent (dry matter basis) enhanced lean muscle mass in these cats.
“The gastrointestinal tract in cats is relatively well protected from the ravages of time,” says Dr. Colin Burrows, an internist and professor of medicine at the University of Florida. “In older cats, just as in older people, the ability to digest diminishes somewhat but it’s not frightfully significant.” Smaller but more frequent meals often help the cat’s body absorb more nutrition.
HILL’S PET NUTRITION HAS ANSWERS
Hill’s Pet Nutrition offers a range of cat foods designed to meet the needs of your aging cat–whether she just celebrated her 7th birthday or 17th. For example, Science Diet® Age Defying™ cat food contains precisely balanced nutrition for senior cats as they age. In fact, Hill’s says you’ll notice a visible change for the better in your cat after just 30 days on this food, including increased play, interaction, and agility, and less potty accidents–and more awake time.
Modern cats age seven and older can still live full, happy and healthy lives. Age is not a disease. These days veterinarians often see still-healthy and vital cats of a great age. “I think if the cat lives to 25 years, I shouldn’t be doing anything but saying hello,” says Steven L. Marks, BVSc, an internist and surgeon at North Carolina State University. “If you’ve ever had a pet live that long, you want them all to live that long.”
Your turn! How old is YOUR cat? What kinds of aging changes have you noticed? Have food changes benefited your furry wonder? Do tell!
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