Questions from the Exam Room

"Aren't all pet foods with corn in them bad foods?"~ A client asked me, "aren't all pet foods with corn in them bad foods?" That got me to thinking how to discuss nutrition in an easy to understand, short answer. This is what I came up with...
Food is composed of five items: protein, fat, starch, vitamins, minerals and some water. Minerals, vitamins and starch are non-changeable - either you have them or you don't. All reputable foods have enough of these for your pet. Fat, with some minor variations, is just fat. Some foods have more of the special fats, such as fish oils. These special oils help the coat and control some types of inflammation, such as arthritis.
People seem to have more problems with understanding protein and what source is the best. American culture suggests that the more meat you eat the better off you are. The most important thing is to give food that matches the animal's needs. For instance, a cow should be fed mostly hay, as it is an herbivore. Lions, tigers and domestic cats are true carnivores and need mostly a meat diet. People, bears and dogs are omnivores as they an get their nutritional needs from many sources.
The problem is which protein source is the best. The answer lies in what makes up a protein. Protein is made up of building blocks called amino acids. There are 23 amino acids, eleven of these have to come from the diet and are called "essential" amino acids. The other twelve can be made by the body. So the question becomes "Are amino acids from meat protein better than the amino acids from plant protein?" The answer is a resounding "NO!" Ask any of your friends who are vegetarians if they get enough protein with the correct building blocks of amino acids. They do get a good diet. So does your pet when you feed a good food. So, to answer the opening question, dog foods with corn in them are not bad food, as long as they are a BALANCED diet.
Dr. T. James Taylor March 5, 2010