We know for sure we are not going to pick corn as a protein source since it contains only four of the ten essential amino acids and contains no taurine, plus nutrition experts didn't even include corn on the list of protein sources in pet foods.  Corn was on the carbohydrate list! 

Canine and Feline Nutrition, on page 175, lists substances that provide protein… beef, chicken, eggs, fish, lamb and meat by-products. (Just so you know… the meat by-products in pet foods as defined by the Association of American Feed Control Officials do NOT contain hair, hide, hooves or feathers, but actually refer to organ meats like liver, kidney, stomach, heart, blood, spleen, etc.)  Meat by-products are a great source of protein for a meat eating animal.

Therefore, for our diet to contain a wide spectrum of amino acids, we will choose to have it contain the best source of protein for mammals. . . eggs, or more precisely the egg whites.  This substance has a wide amino acid profile and is highly digestible.   In fact, egg white is considered a standard against which other protein sources are measured.  Other really good choices would be meat, poultry or fish.

Pet food manufacturers know very well how to make a great diet just like the one we put together.  The problem is that it would be expensive to produce, especially if eggs and beef and fish were in it.  And to be competitive with other pet food producers, the price of the food dictates what the foundation (primary ingredients) of the diet will be.

So for dogs and cats... our custom diet will contain vitamins and minerals, some grain for readily available energy, a proper amount and ratio of fat sources, and as a foundation, a high quality MEAT source.

ENTER CORN... it's cheap, takes up lots of room in the bag of food and in the pet's stomach so it will "fill ‘em up", it's a good carbohydrate source so the pet will have some energy, it has a few amino acids in it so the corn will contribute to the protein totals on the guaranteed analysis list, and there's a cheap and steady supply of corn.  So the pet food manufacturer makes a corn diet, adds some "meat and bone meal" (which has been cooked at least twice before it gets in the bag and may contain too much calcium) to "complete the amino acid profile" and adds a few other calculated substances so that COMPLETE AND BALANCED can be stamped prominently on the pet food label.

The natural world was set up in such a way that, in reference to dog and cat food, cheap ingredients based on plant products and resulting in cheap pet foods always turn out to be a poor choice when attempting to nourish a meat eater.  Conversely, expensive substances such as eggs, meat, poultry and fish are far better choices when designing a good diet for meat eaters.  NOTE! “Expensive” and “costs” are human terms and have no relationship to what Nature set up regarding what constitutes an ideal diet for a meat eater.

Throughout each of the nutrition texts referred to in this article, the authors repeatedly stress the importance of high quality, nutrient dense, and highly digestible pet food products.  Yes, these products will cost the consumer more than the generic brands.   We animal caretakers have an obligation to our animals to strongly favor good quality products and to stop choosing pet foods based strictly upon price. 

Dogs and cats are livelier and healthier when meat, poultry,

lamb and fish are the foundation of their diets.  In other words, we should choose to feed them as the meat eaters they are and denounce the senseless practice of feeding them as if they were herbivores simply because that would be cheaper to do.  According to Case, Carey and Hirakawa in Canine and Feline Nutrition, page 174...

"In general, high-quality animal source proteins provide superior amino acid balances for companion animals, compared with the amino acid balances that are supplied by grain proteins.  The protein in grains is not as balanced or available as the protein in high-quality animal sources..."

By high-quality they are referring to meat, poultry and fish products that are derived mainly from muscle and organ tissue rather than "meat and bone meals".  Some types of animal-derived meals are not considered to be high quality because of the processing they undergo.  A few individuals express concern regarding feeding dogs and cats "high protein" diets.  Blame is laid on "high protein" levels for a spectrum of disorders ranging from epilepsy to hyperactivity to kidney damage.  Attempts to find a  level of protein at which a diet becomes "high" in it are often met with a range of values; nutrition experts do not all agree what level constitutes a “high” level of protein in a dog or cat’s diet.  Purina's labeling of one type of food as Hi Pro (ostensibly conveying the image of an upper level of protein) is very questionable.  The data showing that excess protein causes renal damage are imaginative extrapolations of results derived from test animals that have renal deficits pre-existing and who are then fed levels of protein that induce uremic poisoning.  Early studies that pronounced protein as harmful to dog kidneys were based on studies done on RATS!  They weren't even done on dogs, and that research drove the pet food industry for years.  As it turns out, there are major differences in how the rat kidney (is a rat a meat eater, anyway?) metabolizes protein contrasted to how the canine kidney handles protein.  ThePetCenter invites anyone to produce even one scientific experiment on dogs or cats that proves normal kidneys are harmed by feeding good quality, balanced rations that contain high levels of  protein.

The more one peers into this pet food universe, the more one is impressed as to how much we have yet to learn.  And much of what one learns is self-taught.  Nutrition and pets. . . very interesting topics and worthy of our sincere investigation.

How does the consumer know what to buy?  All you really have time for is to read the label, see the fancy packaging, and note that it says "Complete and Balanced" and you will buy with a confidence instilled by the advertising claims.  To confuse things even more, some very reputable major pet food companies make many different foods of varying quality and price levels.  Some products are high quality and some barely meet the minimum requirements for dogs and cats.  Plus... economic  principles drives the need to offer products in various price ranges to meet the demands of pet owners.  Unfortunately for some pets the "pet food" they receive may be minimally nourishing.