Corn for dogs has been a controversial subject for years now with many claims made against this grain. When looking at the facts, can dogs eat corn or not, and is corn bad for dogs in any way?
Currently, there’s no research suggesting that corn may be bad for canines. The short answer is yes, dogs can eat corn, but there’s more to this.
Corn being a grain is one of the more contentious ingredients commonly used in dog food. Due to an overwhelming amount of misinformation online, current trends in popular culture tend to frown upon feeding this common grain to dogs.
But how true are these negative accusations surrounding corn for dogs? In this article we’ll answer common questions about corn and its use in dog food.
What is Corn?
Corn is one of the most popular cereal grains in the world. Wholegrain corn is a completely healthy cereal grain. It contains minerals, vitamins, amino acids, antioxidants and fiber.
Corn is primarily a source of carbohydrates. It also contains a large amount of water, as well as medium and low amounts of protein and fats, respectively.
Corn is a low-fat food and has up to 6% of fats, which are derived to make corn oil (1).
Why is Corn in Dog Food?
Corn is subsidized by the Farm Bill every year, and therefore it allows pet food companies to be economical, often passing those savings onto the consumer.
When you combine this with the fact that most veterinary nutritionists agree that corn for dogs is not a problem at all, and can in fact be a part of a well balanced canine diet, this becomes a reasonable ingredient.
Can Dogs Digest Corn?
This is one of the most common myths about corn for dogs – its digestibility. Owners are concerned that corn causes bloating in dogs, and that a canine body was not designed to digest corn. That is not true, however.
Most dogs can digest corn with no problems. There is no scientific evidence to suggest that the nutrients in corn are poorly digestible by canines. In fact, the opposite is true (9).
Whole grain kernels contain quite a bit of non-digestible fiber, but after being ground into finer particles (for example, by chewing), or separated into its components, corn is very digestible.
Even veterinary prescription diets designed to be extremely gentle on the canine GI track and easy to digest for dogs utilize corn as an ingredient because there’s no reason not to.
How dogs digest corn
A dog’s body produces potent pancreatic amylase as well as brush border enzymes to digest carbohydrates, just like a human’s body does. Most digestion of corn occurs in the first part of the small intestine (13).
It is true that like humans, dogs cannot digest cellulose – a single structural carbohydrate used by plants to form stalks and seed coats. Only herbivores like cows can digest cellulose, turning it into some other vital nutrient.
Therefore, cooking the corn or otherwise grinding or making particles smaller is necessary to derive the nutritional benefits contained in them.
Corn vs Corn Gluten vs Corn Gluten Meal
There is difference between corn, corn gluten and corn gluten meal. Grains can be fractioned or divided into their components in order to concentrate and separate the nutrients.
This allows pet food manufacturers to add specific nutrients to the canine diet in order to make it balanced and more healthy for dogs. Corn milling produces byproducts as well, such as corn oil, which isn’t as healthy as wholegrain corn.
In general, corn can be divided into:
- Corn oil – a source of fat, which is not recommended for anybody;
- Corn starch, which is considered a highly digestible carbohydrate source;
- Corn bran – a source of fiber;
- Corn gluten meal, which is a concentrated source of protein.
Neither is inferior to the other, they are just used for different nutritional purposes.
Are Dogs Allergic to Corn?
Another common myth about corn for dogs is that canines are inherently allergic to corn. It is a false assumption that most dogs are allergic to corn, but some indeed are. There have been noted corn allergies in dogs.
In fact, further research suggests that few dogs are actually allergic to their food (23, 24, 25). Of all the foods that dogs are allergic to, evidence shows that the most common are beef, dairy, and wheat; not corn (26).
Corn and Dogs’ Carnivorous Diet
Not a myth, but a common reason among owners arguing against corn for dogs is that canines are carnivores and there’s no reason to feed them grains like corn.
Dogs are not obligate carnivores and instead are omnivores (like humans). Canines need a little bit of everything for their diet to be nutritionally balanced.
Studies show that dogs fed an exclusively all-meat diet without supplementing with minerals and vitamins that the meat diet is lacking will develop health problems, such as secondary hyperparathyroidism (27).
Protein in Corn
It is true that the amino acid profile (which comes from protein) of corn is not the same as that of animal-origin products.
In order for dogs to meet 100% of their daily protein requirements, corn alone cannot be used. It has to be combined with another food source that supplies appropriate amounts of amino acids.
Do Dogs Need Corn?
It is true that dogs do not require dietary sources of carbohydrates found in grains like corn (they do require a cellular form of carbohydrates).
However, they can still benefit from carbohydrate source in the diet (30). For example, fiber can be beneficial for the growth of probiotic bacteria in the gut.
Is Corn Considered a “Filler Ingredient”?
There’s currently no legal definition of “filler” in pet foods. In general, it’s accepted that “filler” refers to something added to a canine diet to bulk it up without adding much in terms of nutritional value.
Corn does not fit that description. It actually contains a balance of nutrients not found in other grains.
Moreover, corn provides dogs with a highly available source of complex carbohydrates and substantial quantities of linoleic acid, an essential fatty acid important for canine’s healthy skin. Corn for dogs also supplies essential amino acids and fiber.
Isn’t Corn Poorly Nutritious?
Protein quality is defined by the content of essential amino acids and the digestibility of the protein. Corn gluten meal doesn’t contains 100% of all of the essential amino acids dogs need.
For example, corn protein has little lysine. So, if corn for dogs is used alone and without supplementation, the quality would be low.
However, when used with complementary proteins (proteins that are abundant in each other’s limiting amino acids), dog foods with corn can form complete canine diets with an excellent balance of amino acids for a highly digestible, high quality total protein source.
Take Home Message
Corn has been vilified in popular culture as a poor ingredient in dog food, which isn’t the case. It can be nutritious when paired with complementary proteins and nutrients to be a balanced part of a canine diet. It has many essential nutrients and is easily digested.
Corn for dogs is mostly economical, allowing to purchase good quality dog food for cheaper.
Just like people, domesticated dogs have evolved to digest carbohydrates, and corn in particular. This discredits the theory that ancestral canine diets are best for modern dogs. Of course a diet of just corn wouldn’t be healthy, but corn can be part of a healthy canine diet.