My young dog recently had an obstruction in his large intestine which required surgery. The vet removed a small piece of corn husk (the inner, hard centre of a corncob with the kernels removed) from his gut. My puppy “stole” the husk from the worm farm and clearly, was unable to digest it. But what about corn kernels, are they safe for dogs to eat?

Is corn good for dogs?

Corn is also known as maize. It is the most commonly grown cereal in the world followed by rice and wheat. Nutritionally, corn kernels, like other cereals consist of 61% – 78% starch, 10% nonstarch polysaccharides, 6 – 12 % protein, and 3% – 6% lipids.

The starch content of corn comprises two types of polysaccharides: amylose and amylopectin. Starch is stored in the dog’s body as glycogen. Glycogen functions to help to maintain normal glucose homeostasis.

Cellulose and hemicellulose are the major nonstarch polysaccharides found in corn. Nonstarch polysaccharides are also referred to as dietary fibre. Dogs are unable to directly digest dietary fibre however microbes in the large intestine are able to partially break down certain types of fibre.

As a source of protein, corn is lower quality than animal protein which contains all the essential amino acids. Corn, like all grains, is deficient in the amino acid lysine. Lysine is an essential amino acid as it is required for the synthesis of protein in every cell within the dog’s body. Lysine is susceptible to destruction when exposed to heat (such as in the cooking process to produce dry dog food).

While, lipids or fats comprise a small proportion of the nutritional value of corn kernels, corn oil is a good source of omega 6 fatty acid.

Is corn safe for dogs to eat?

In the western world, corn is typically milled to produce a range of food ingredients. Including corn oil, corn starch, and corn flour. The “coproducts” of the milling process are typically used as animal feed including dog food. Corn “coproducts” in common dry dog food products include: maize, maize gluten, maize flour, corn gluten meal, and whole grain corn. These ingredients are included in commercial dog food as a protein source and to aid the extrusion process to produce dog “biscuits” or kibble.

While the nutrients in corn (and indeed all ingredients) are compromised by the milling and manufacturing processes required to produce commercial dog food, corn appears to be “safe” for dogs to eat, at least in the short term.

Fed raw as part of a vegetable mix, corn is also safe albeit not very nutritious or easy to digest for a dog. Better sources of protein, vitamins, fats, and minerals are raw animal products (i.e. meat, bone, organ meat and eggs) accompanied by raw fruit and vegetables.

Until next time, enjoy your dogs.

Sources

http://www.royalcanin.com.au/products/products/dog-products/size-health-nutrition/medium-dogs-11-25kg/medium-dermacomfort [17/12/2017]

http://www.royalcanin.com.au/products/products/dog-products/size-health-nutrition/medium-dogs-11-25kg/medium-adult [17/12/2017]

http://www.hillspet.com.au/en-au/products/sd-canine-adult-large-breed-dry.html [17/12/2017]

https://www.supercoat.com.au/pet-food/products/supercoat-active-dog-with-real-kangaroo/ [17/12/2017]

https://www.eukanuba.com.au/dog-food/puppy/puppy-large-breed/ [17/12/2017]

Ai, Y. and Jane, J.-l. (2016), Macronutrients in Corn and Human Nutrition. Comprehensive reviews in food science and food safety, 15: 581–598. doi:10.1111/1541-4337.12192