Excerpt from…
Diabetes and Obesity by Elizabeth Hodgkins, DVM
“First, let me say that there is no ONE cause of adult onset (Type II) diabetes (diabetes mellitus or DM) in the cat. The disease, like most diseases, is multi-factorial in the cat, as well as in humans. In fact, the feline version of type II diabetes is more like human type II diabetes than this condition in any other species that has been studied.
Type II DM is not an autoimmune disease, but genetics certainly do play a part. Certain cats are predisposed to developing adult onset DM, while others simply are not. However, type II DM in even predisposed cats is not commonly a matter of auto antibodies being produced against pancreatic tissue as is true if other autoimmune diseases (some cats do produce antibodies to injected insulin from other species used to treat feline diabetics but that is not the same as an autoimmune phenomenon causing the diabetes in the first place). In fact, there are some extremely important environmental factors, and inappropriate diet is chief among these.
The cat is an obligatory carnivore. As such, it is dependant for good health upon a diet that is very high (greater than 50-60%) in animal source protein. In the wild, cats seek out diets that have nutrient profiles with at least this much protein, about 30-40% fat, and 1-2% carbohydrate. Unfortunately, the extruded dry foods we feed our pet cats today has a very distorted nutrient profile for cats (just as the present, government-recommended, high carbohydrate diet for humans has a distorted nutrient profile for humans).
Most of these dry cat foods contain very high amounts of cereal grains in order to make it possible to put the ingredients through an extruder to produce “popped” kibble product. The result is a food that has 18-30% protein, 15-22% fat, and as much 40-60% predigested starch (read sugar!). As this kind of diet has become more and more popular as a sole diet for pet cats in our society, those pet cats have become fatter and fatter (like people on a high carbohydrate diet, only worse) over the past few years, and the incidence of type II DM has soared among that same population. Ask any vet if he or she is seeing a lot more of this disease among his/her patients than a decade ago. The answer will be “yes!”
It is certainly true than most serious cat breeders do not have a lot of problems with this disease. The reason is not just that those breeders have skillfully bred genetically DM resistant cats, however, although that can be a part of the whole story. The larger reason is that most, if not all, breeders feed a significant amount of canned foods and fresh raw or cooked meats. Although most breeders do provide dry cat foods to their cats, the diet of their breeding animals is not even close to 100% dry food, as is often the case with pet cats in 1-3 cat households.
Consumption of dry cat food causes a very rapid and extreme surge in blood glucose as the predigested carbohydrate in the food is dissolved and absorbed into the bloodstream essentially as sugar from the stomach and intestines. This rapid rise in blood glucose causes the pancreas to secret a much larger amount of insulin in response than would be needed with a more natural, high protein, moderate fat diet. Ultimately, the constant abnormal stimulation either suppresses or exhausts the pancreas (we’re not sure exactly which, yet), and clinical diabetes results. This process takes months to years to occur, depending on the individual cat’s ability to withstand the effects of this abnormal metabolic effect. Along the way, the constant high insulin levels (hyperinsulinemia) cause the cat to experience hypertriglyceridemia (high triglycerides) and hypercholesterolemia (high cholesterol), and obesity results.
Our research has shown that weight reduction in even the most obese (but otherwise healthy) cat is no more complicated than withholding all dry food, and providing free choice canned food or fresh meat as the sole diet. Thus, although I agree that obesity does not cause type II DM, DM and obesity have common causes in the cat and in humans as well.
Excessive carbohydrate consumption, over time, causes both obesity and strongly predisposes the cat, an obligatory carnivore, to the metabolic “train wreak” we know as type II feline diabetes mellitus. Once this condition exists, effective treatment absolutely requires that a high protein, moderate fat and low carbohydrate diet be used in these patients. High fiber diets like w/d and r/d (and their analogs by other companies) DO NOT WORK, and they do not work because they are loaded with carbohydrate that continues to dump sugar into the blood stream of an animal that already has problems handling sugar.
For now, there is compelling scientific evidence to show that high carbohydrate diets (essentially all dry cat foods) fed to pet cats on a continuous and exclusive basis predispose to, or even directly cause, feline obesity and type II feline diabetes mellitus. In time, I believe we will learn that other common feline maladies, such as hyperthyroidism and urinary tract disease, are also related to this very abnormal and non-physiological practice of feeding large amounts of carbohydrate to animals not at all equipped to handle this nutrient in such quantities. Conscientious breeders will want to keep their eyes on the research into this very important aspect of cat breeding and proper cat husbandry.”
