I'll be very surprised if I don't start a bit of a firestorm with this topic, as it's a pretty heated one among dog and cat owners. So let's get to it!
Recently I had a client whose one year old cat developed a urinary blockage. They brought him in quickly and he was unblocked, hospitalized, and recovered without any problems. To prevent further events like this (it is life-threatening and expensive to treat) I recommended a veterinary-only urinary diet. One of the pair was really hesitant to do so because the food contained corn and she had been under the impression that this was a bad thing. Eventually I convinced her that the urinary food was the best thing for her pet, but it took some work. Like many pet owners she has some misconceptions about corn. I want to spend a little time busting some myths about corn in dog and cat food.
Myth #1: Corn Is Filler
You've probably heard this one a lot and it's completely untrue. "Fillers" have no nutritional value and are there to simply make up bulk in food. Pet food companies have decades of research to determine the ingredients, and don't put anything in the food that they don't really need to. Some ingredients may not be as high quality as others, but few are ever "filler". Take corn for example. A kernel is about 80% carbohydrates, which are a great source of energy. This portion of corn is over 95% digestible and is not wasted. To further improve quality, food companies don't use whole kernels. Instead they use corn starch which is processed to the point of reaching up to 99.5% purity for carbohydrates. Corn is also high in carotenoids, which are involved in aiding vision, skin health, bone and muscle growth, and act as antioxidants. Filler? I don't think so.
Myth #2: Corn Is Poor Protein
When most people think of corn they think of the kernels we eat and how they can come out the end opposite the mouth and still appear intact. These kernels indeed have limited nutritional value. However, in pet foods on specific forms of processed corn are used, such as corn gluten meal. This corn product is basically purified protein which has been separated from the other parts of the kernel (such as the hull). Corn gluten is highly digestible, has a great amino acid profile, and is considered to be similar in quality to fish meal. While I certainly don't think that corn should be the only source of protein, it does make an excellent compliment to other protein in the diet.
Myth #4: Corn Causes Food Allergies
While food allergies do occur in pets and there are several ingredients commonly known to cause an allergy in sensitive animals, corn is not one of them. Overall only about 3% of dogs and cats have food-related allergies. Of the pets who have a confirmed food allergy, only about 1.5% of them will react to corn. Putting it another way, 98.5% of pets with food allergies don't have a problem with corn. And these are the ones with food hypersensitivites! Corn is actually one of the ingredients least likely to cause a reaction. Wheat, beef and chicken are much more likely to be allergens, yet we don't see people trying to avoid these ingredients in an average pet.
While food allergies do occur in pets and there are several ingredients commonly known to cause an allergy in sensitive animals, corn is not one of them. Overall only about 3% of dogs and cats have food-related allergies. Of the pets who have a confirmed food allergy, only about 1.5% of them will react to corn. Putting it another way, 98.5% of pets with food allergies don't have a problem with corn. And these are the ones with food hypersensitivites! Corn is actually one of the ingredients least likely to cause a reaction. Wheat, beef and chicken are much more likely to be allergens, yet we don't see people trying to avoid these ingredients in an average pet.
Myth #4: Since Corn Isn't Eaten By Wild Dogs And Cats It Shouldn't Be In Their food
If you look at it a certain way, this myth actually has a kernel of truth (*rimshot*). The wild ancscestors and cousins of our pet dogs and cats don't typically eat plant material and the type corn in human and pet diets isn't found in the wild. However, remember that wild carnivores eat herbivores and the prey eat plant material. When a wolf or wild cat catches prey it eats the entire thing, including the digestive tract and its contents. So predators actually do eat plant material. The difference is that these plants are partially digested and found in the stomach and intestines. Besides, if we eliminated everything that a dog or cat wouldn't eat in the wild we'd eliminate virtually every pet food. Instead we'd be feeding cats whole mice and birds, and dogs would be allowed to dine on deer carcases and rodents.
Reading the ingredient label on pet food bags isn't as simple as it may seem and there is a lot of misinformation that is perpetuated by some breeders, pet owners, and even food companies (to convince people that their competitors are bad). I'll talk about some of the other hints on pet foods at a later date, but for now you can be assured that corn isn't something you have to avoid in the foods.
