Corn

There are pros and cons about CORN as an ingredient in pet foods.
In truth, it’s not BAD.  Before I shifted to holistic pet foods, I did feed my pets corn-based foods and one kitty lived to be twenty.

On the other hand…  I had to have two kitties put to sleep within three weeks of shifting them to a new premium pet food where the first three ingredients were corn products. 

So I am “corn-shy”.

Let me just tell you what veterinarians say, pro and con, about the use of corn in pet foods.  I am anti-CORN, all holistic vets are anti-CORN (except when needed for prescription diets), and yet, commercial pet foods use Corn as a primary protein source.

PRO-CORNFlint River Ranch, a popular “natural” pet food, says this about its use of corn and wheat in its pet foods:

GRAIN
Wheat and Rice. Whole wheat and selected parts of the wheat berry are used as our base grain. Wheat grains are not only more digestible than corn, it is one of the most nutritionally balanced cereal grains. It is an easy-to-digest source of carbohydrates, fiber and energy. A combination of grains, like a combination of meats, is better than just one source. Low quality fillers like wood fiber, corn cobs, peanut hulls, cottonseed, straw, soy beans or citrus pulp are never found in Flint River Ranch products.

SOURCE OF GRAINS:
Grains are purchased from major commercial suppliers like General Mills - fully tested and retested when received. This testing ensures the very best quality and reduces the possibility of toxic molds. Grain is cheaper when purchased direct from the farm however, the risk of toxic mold is greater.

RICE:
A combination of brown and white rice. The white rice for digestibility and the brown for its added nutritional value. A diet product that is 100% brown rice can be somewhat hard for some animals to digest.

WHEAT:
Wheat flour is a fine-ground whole wheat grain. A coarse-ground whole wheat is also added for texture, along with a quality wheat berry.

CORN:
Corn is an excellent grain; however, it is more difficult to digest than rice - either by humans or dogs. Therefore, corn is not used as an ingredient in our dog food. The feline digestive systems better utilize corn and supplies important diet benefits to cats and kittens. Corn is included in the feline formulas.

Here is what Purina says about corn as a protein source:

Sources of Protein

Protein is derived from both animal and plant sources. Most protein ingredients contain inadequate amounts of one or more amino acids and are thus inefficient if used as the sole source for meeting protein needs. However, by careful selection and combination of different protein sources, these inefficiencies can be completely overcome. For example, soybean meal and corn complement each other perfectly, because the amino acids which are deficient in one are present in the other. Neither meat nor soybean meal is an ideal source of protein; however, either can be adequate if fed in combination with another complementary source of amino acids.

Protein Digestibility

To evaluate the protein levels of different dog foods, two factors should be considered. One is the level of protein and the other is the protein digestibility, or availability of the protein to a dog, which can be determined only by controlled feeding studies. Two diets may have the same protein level listed on their packages, but the results of dog digestion studies may indicate very different levels of protein digestibility. For example, a dog food which contains 21% protein with 85% digestibility would deliver equal amounts of protein as a diet containing 23% protein with 78% digestibility.

In addition to the protein level, quality control during processing of dog foods is important. Protein may be damaged by excessive heat processing, but most reputable dog food manufacturers use proper cooking methods and employ quality control measures to ensure that products are made properly. Because information about protein digestibility is not listed on dog food labels, the manufacturer’s reputation is important.

CON-CORN 

The Pet Food Institute wonders why were are including so much grain in our pets diets.  Cats, especially, are true carnivores.  They suggest that grains are a cheap source of protein.

Wheat, Soy, Corn, Peanut Hulls, and Other Vegetable Protein

The amount of grain products used in pet food has risen over the last decade. Once considered filler by the pet food industry, cereal and grain products now replace a considerable proportion of the meat that was used in the first commercial pet foods. The availability of nutrients in these products is dependent upon the digestibility of the grain. The amount and type of carbohydrate in pet food determines the amount of nutrient value the animal actually gets. Dogs and cats can almost completely absorb carbohydrates from some grains, such as white rice. Up to 20% of the nutritional value of other grains can escape digestion. The availability of nutrients for wheat, beans, and oats is poor. The nutrients in potatoes and corn are far less available than those in rice. Some ingredients, such as peanut hulls, are used for filler or fiber, and have no significant nutritional value.

Two of the top three ingredients in pet foods, particularly dry foods, are almost always some form of grain products. Pedigree Performance Food for Dogs lists Ground Corn, Chicken By-Product Meal, and Corn Gluten Meal as its top three ingredients. 9 Lives Crunchy Meals for cats lists Ground Yellow Corn, Corn Gluten Meal, and Poultry By-Product Meal as its first three ingredients. Since cats are true carnivores — they must eat meat to fulfill certain physiological needs — one may wonder why we are feeding a corn-based product to them. The answer is that corn is a much cheaper “energy source” than meat.

Digestibility and bioavailability are debatable among veterinarians.  However, numerous pet food recalls are due to  fungus that grows on corn and wheat,  called “aflatoxin” and “vomitoxin”, respectively.  Folks, these poisons kill.  Testing for these fungii is standard practice in the pet food industry, yet they STILL make it into our pets foods.

Top holistic vet Dr. Jean Hofve says that cats, in particular, are true carnivores and states that many diseases cats suffer are DIET-related:

Cats are true carnivores, requiring a meat-based diet for optimal health. Their natural diet is, of course, prey such as rodents, insects, and birds. These prey consist primarily of water, protein and fat, with only about 10% carbohydrate (starch, sugar and fiber) content. Cats are exquisitely adapted to utilize fat and protein for energy, as opposed to omnivores like dogs and people, who mainly use carbohydrates for energy.

When feeding our companion cats, the most logical strategy is to feed the diet that most closely mimics the natural prey diet. The best way to do this is with a homemade diet; however, not everyone is ready for this step. Feeding more (or only) canned food is another alternative. Canned foods are higher in fat and protein, and lower in carbs, than dry foods. Their high water content increases the cat’s overall fluid intake, which keeps the kidneys and bladder healthy, and is more filling.

Recent research has shown that high-carbohydrate diets, such as dry and semi-moist foods, are to blame in most cases of feline diabetes. It is likely that many overweight cats are carbohydrate-intolerant, and should be fed low-carb diets (think “Atkins diet” for cats!). More information on the link between diet and diabetes is contained in the full report, “What Cats Should Eat.”

Nutrition-Related Diseases

In fact, not only diabetes but many serious health problems in cats have a dietary component. Some are actually caused by diet, and all are affected by it. Diet-related diseases include:

• Obesity
• Chronic Vomiting
• Hepatic Lipidosis
• Pancreatitis
• Arthritis
• Heart Disease
• Asthma
• Allergies
• Inflammatory Bowel Disease
• Chronic Renal Failure
• Lower Urinary Tract Disease
• Hyperthyroidism
• Viral Conjunctivitis
• Skin and Coat Problems

Holistic Vet Dr. Lisa Pierson says that grains should be absent from pet foods, especially cat food:

Grains should be absent or, at least, minimal in amount. This means if they are present, they should not be among the first three ingredients. Corn and wheat are thought to be common allergens when compared to other grains such as rice, oats or barley so it is best to choose a food that does not contain corn or wheat.

She goes on to list the host of health problems in cats that are diet-related:

Common Feline Health Problems and Their Ties to Diet

There is a very strong and extremely logical connection between the way that we are currently feeding our obligate carnivores and many of the life-threatening diseases that afflict them.

• • Diabetes: Diabetes is a very serious – and difficult to manage – disease that is very common in cats. Why is it so common? The species-inappropriate high level of carbohydrates in dry food wreaks havoc on the blood sugar level of an obligate carnivore. The blood sugar level rises significantly upon ingestion of dry food. With chronic hyperglycemia (high blood sugar) the insulin producing cells in the pancreas down-regulate, or “burn out,” leading to diabetes.

  • Kidney Failure: Kidney disease is probably the Number One cause of mortality in the cat. It is troubling to think about the role that chronic dehydration plays in feline kidney failure. And remember, cats are chronically dehydrated when they are on a diet of predominantly dry food.

  • Cystitis (bladder inflammation) and Bladder/Kidney Stones: Cystitis and stones are extremely common in the cat. The concentration (specific gravity) of the urine is a critical factor in contributing to, or preventing, these serious health issues. Some cats have a higher tendency to form crystals in their urine. Cats on dry food have more highly concentrated urine (higher specific gravity) which means that a higher concentration of stone-forming crystals will be present in the urine. This increases the chance of producing life-threatening stones. Also, a very concentrated level of crystals acts like 60-grit sandpaper on the delicate bladder wall, which can lead to painful cystitis. Cystitis can lead to inappropriate urination (urinating outside of the litter box) and stones can cause a fatal rupture of the bladder. (Any cat that is repeatedly entering the litter box but not voiding any urine is in need of IMMEDIATE medical attention!) Cats eating canned food are more appropriately hydrated, and therefore, have more dilute urine (lower specific gravity). This greatly decreases their chance for urinary tract problems.

  • Inflammatory Bowel Disease (IBD): IBD is thought to be a common cause of vomiting and diarrhea in the cat. There are many unanswered questions with respect to this disease process, but it seems logical to start to “treat” a gastrointestinal problem in the cat with a species-appropriate diet. Too often these cats are treated with a high level of steroids and a so-called “prescription” DRY diet. I feel very strongly that this common therapeutic regimen needs to be re-evaluated. There are an impressive number of anecdotal reports of cats that were terribly ill with IBD exhibiting dramatic improvement when ALL dry food was removed from their diet. Taking it even one step further, there are many reports of cats with IBD that improved tremendously on a balanced, grainless, raw diet. (See Resource List for more information.)

  • Obesity: Obligate carnivores are designed to meet their energy needs with a high protein, moderate fat diet. Carbohydrates are minimally used. Those that are not used for energy are converted to and stored as fat. The so-called “light” diets that are on the market have targeted the fat content as the nutrient to be decreased, but in doing so, the pet food manufacturers have increased the grain fraction, leading to a higher level of carbohydrates. Hence, many overweight cats eating these “light” diets are still obese. These products are among the most species-inappropriate diets available to cat caretakers.

  • Hepatic Lipidosis (Fatty Liver Disease): This is the most common metabolic liver disease of cats. Overweight cats that go longer than 48 hours without eating, for any reason, are in danger of developing this serious, and often fatal, disease. Feeding a high-protein, low-carbohydrate diet helps keep cats at an optimal, healthy body weight.

  • Dental Disease: Long-standing claims that cats have less dental disease when they are fed dry food versus canned food are grossly overrated, inaccurate, and are not supported by recent studies. First, dry food is hard, but brittle, and merely shatters with little to no abrasive effect on the teeth. Second, the high carbohydrate (read: sugar) level in dry foods has been shown to cause dental decay. Third, many cats swallow the majority of their dry food whole and thus receive minimal benefit from chewing motion. Finally, a meat-based diet results in an acidic oral environment which may actually prevent some forms of dental disease. There are many factors that contribute to dental disease in the cat such as genetics, viruses, and diet. There remain many unanswered questions concerning the impact of diet on dental health, but feeding a high starch, species-inappropriate dry diet is a negative factor. Perhaps, a more natural way to promote dental health is to feed large chunks of raw meat. (See below for ‘Home Prepared Diets’.)

Personally, I refuse to feed my kitties anything with corn.  The holistic pet foods that I’ve come to trust over the last ten years don’t cost any more than a Science Diet or an Iams, two of the most popular corn-based pet foods in America.

If I can help my pets live longer, happier, healthier lives as a result of taking a little extra care in feeding them, I’ll have done my job as a pet parent.