Feline Diabetes: Is Nutrition the Key to Preventing and Treating an Epidemic?

We’ve all heard on the news that there’s an epidemic of type 2 diabetes in American humans right now, but some of you may not know that this applies to our cats, too. What is the reason for the prevalence of this condition in cats, what can we do to prevent it, and are there alternative methods of treating it besides insulin injections?

Let me state in no uncertain terms that if your cat is currently diagnosed with diabetes and is on insulin injections, you must work under veterinary supervision if you are going to try any dietary changes in the hope of reducing or eliminating the cat’s dependence on insulin. Even just changing the cat’s diet can change his or her insulin requirement, and you could kill your cat.

Common wisdom on nutrition for cats with diabetes has, for many years, centered on the use of high fiber diets. Fiber has been shown to minimize the impact of dietary carbohydrate on blood sugar, in cats as well as in humans. But recent research by Purina revealed that reducing the amount of dietary carbohydrate in the feline diet can get more than 50 percent of cats off insulin. In fact, Purina has come out with a new “low carb” prescription cat food specifically for the treatment of feline diabetes, Purina DM. Vets now dub this approach “Catkins,” after the late Dr. Robert Atkins, who developed a low carb weight loss and diabetes control program for people.

According to Deborah S. Greco, DVM, PhD, Diplomate ACVIM, Associate Professor at the College of Veterinary Medicine and Biomedical Sciences at Colorado State University, in the early 90s one in 400 cats were found to have diabetes. Today, that rate has doubled. Many vets, including Dr. Greco, speculate that the growing reliance on high-carbohydrate kibbles may be partially to blame for this increase.

According to Dr. Greco, "The cat is an obligate carnivore and as such is unique among mammals in its insulin response to dietary carbohydrates, protein and fat.... (T)he cat is uniquely adapted to a carnivorous diet and is not metabolically adapted to ingestion of excess carbohydrate."

That cats have no dietary requirement for carbohydrate is no secret to pet food manufacturers, although it seems to surprise many cat owners and even some veterinarians. According to The Waltham Book of Dog and Cat Nutrition, "There is no known minimum dietary carbohydrate requirement for either the dog or the cat.” (This does of course make me ask why, then, Waltham makes several brands of high-carbohydrate dog and cat foods, such as “Whiskas,” which contains corn as its first ingredient and corn gluten meal as the third ingredient, plus other grains further down the list.)

Recently, an article called “The Carnivore Connection to Nutrition in Cats” by Debra L. Zoran, DVM, PhD, DACVIM, appeared in the prestigious Journal of the American Veterinary Medical Association. In it, Dr. Zoran took a look at many different feline conditions that might be related to inappropriate consumption of foods high in dietary carbohydrate, including obesity and diabetes. She wrote, “Dietary recommendations extrapolated from recommendations for humans and dogs are to feed affected cats diets high in insoluble or mixed fiber. However, with the increased understanding of unique protein and (carbohydrate) metabolism in cats, these recommendations have been challenged. High-protein, low-(carbohydrate) diets and low-fiber diets are highly beneficial in the management of cats with diabetes, resulting in a reduction of greater than 50 percent in the amount of insulin required in 8 of 9 cats in one study. In another study, complete cessation of insulin administration was reported for one-third of the cats. In another study, 49 researchers reported that contrary to what is observed in dogs, cats fed diets containing soluble or insoluble fiber had altered glucose tolerance. Another study reported that feeding typical adult maintenance diets to cats resulted in development of greater postprandial hyperinsulinemia, even in cats with normal body weights, compared to cats consuming a high-protein diet.”

She concluded, “(A) reduction in dietary starch will substantially reduce the insulin requirement (endogenous and exogenous) in affected cats.”

What is the best way to feed a cat? Each of us has our stories of cats who lived to a ripe old age eating in a certain way: Raw, cooked, kibble, canned, and combinations thereof. Especially with cats who go outside and are thus likely getting additions to their diets that we don't know about (some of them very healthy, such as insects and mice, others not so healthy, such as the generic dog kibble your neighbor has down for Fido), it's really impossible to evaluate the impact of nutrition for any individual cat's lifespan and health.

But we can make some broad generalizations about small felines. One of them is that since cats are strict carnivores and have no dietary requirement for carbohydrate, it's not likely to be a good idea to feed them a food that is comprised largely of carbohydrate (as all kibble is). To quote Dr. Zoran, “Although cats have adjusted to most manufactured diets, the limitations of substituting animal-origin nutrients with plant-origin nutrients in foods formulated for cats are being increasingly realized.”

Doesn’t it simply make sense to seek out a way of feeding our cats that's more in tune with the diet the species evolved eating, than a grain-based, high carbohydrate, dry, processed food? Wouldn’t it be more logical to seek out canned, frozen, and fresh, homemade diets that are meat-based rather than grain-based? There are commercial canned foods, such as Nature’s Variety, that contain 95 percent meat and are complete and balanced for a cat. Homemade recipes can be found in a number of sources, including many grain-free recipes in the book Home Prepared Dog and Cat Diets: The Healthful Alternative by Donald Strombeck DVM, PhD. The website and email list Holisticat, at http://www.holisticat.com, is a wonderful source of recipes and encouragement for those looking for better ways to nourish their feline friends.

It's up to each of us to decide how we want to feed our cats. There's no shortage of opinions on this issue, and no shortage of vets who will gasp in dismay at the idea of feeding anything but kibble to a cat or dog. Whether your cat has diabetes, is obese, or you simply want to maintain his or her current good health, consider the lessons of biology and nature when deciding what to feed that tiny tiger you have purring in your lap.