Nutrition for Pets: Navigating Uncharted Waters

Abstract

damage done by food that is either inappropriate to the animal or fed inappropriately. Cats are a microcosm for this problem since of all veterinary species they are the hardest hit by the controversies and changing opinions in pet nutrition, whereas type II diabetes in cats and in humans are similar enough to warrant closer attention to this little masterpiece of an animal. Veterinarians can be just as emotional about food as the pet owners they work with and educate. Gone are the days when a cat or dog could be maintained on table food, but there is no agreement in the profession on how to use science as a foundation for nutrition. There is among North American veterinarians an unspoken yet strong loyalty to major pet food companies (the “big four”) based on the fact that these companies do extensive research that began in the 1950s with the first Hill’s diet for Buddy, a German shepherd with ailing kidneys. As scientists we have innate respect for the concept of research, but such respect should not translate into religious acceptance of the bags and cans of food that emerge from a company’s plant. One problem is that research into animal nutrition has become part of mainstream science which in turn is governed by economics and the realities of agriculture. The human food pyramid is a good illustration of this principle: the starting point is a food source that is plentiful and relatively cheap to produce (wheat and corn), and the goal is to study how this source can be utilized in a way acceptable to health. The same approach is used in research into animal nutrition. However, acceptable is by far not the same as optimal. Cats are indeed capable of utilizing carbohydrates sourced from grains - by storing them away as body fat. The unfortunate popularity of dry foods is responsible for the epidemic of obesity among cats, for the common problem of urinary crystals that often lead to painful and life-threatening urinary obstruction in younger cats, and quite possibly for an earlier onset of kidney insufficiency in older cats who live in a state of sub-clinical dehydration if they do not drink enough water. (Descended from desert animals, cats do not have a thirst drive separate from hunger, as as such do not have a reason to drink water.) The other problem is that of implementation. If a pet food company’s research shows that rice has the highest glycemic index of commonly used carbohydrate sources, and that same company uses rice in a food designed for diabetic cats, it is wise to learn the scientific lesson but look for a food that reflects it better. The public’s disenchantment with major pet food companies has led to a backlash against science itself and nostalgia for the poorly defined concept of what is “natural.” It is easy to forget that the things we value about food and the experience of eating are very far from “natural.” It is unnatural for animals (and people) to be picky about their food. It is unnatural and to a large extent unhealthy to be full and absolutely hunger-free all the time, yet freedom from hunger (itself a very subjective