While whole sweet corn kernels can make it intact through the intestines of both dogs and cats (and humans!) and be visible in the feces, especially if not thoroughly chewed, this doesn’t mean that corn isn’t a safe and nutritious food.
While grains and especially corn are often thought to be common allergens by pet owners, the scientific data does not support this perception. Overall, food allergies are uncommon in pets and the vast majority of pets with food.
Corn is an excellent source of the essential fatty acid, linoleic acid. Linoleic acid is an omega-6 fatty acid and it is required to be provided by the diet in dogs, cats, and humans.
Corn can be a good source of energy from both starch (carbohydrate) and from fat (as mentioned above). Whole ground corn also contains some corn bran, which is an insoluble fiber source which can contribute to good fecal quality.
While the protein component of corn is called “gluten”, it is quite different from the protein found in wheat, rye, and related grains that is associated with gluten-intolerance.
The majority of corn that is used for human and animal feeding in the US is genetically-modified (GMO) to be resistant to common herbicides.
Genetically-modified organisms require extensive safety testing prior to FDA approval. GMO corn strains have been available for more than two decades.
Avoid giving your dog access to corn on the cob or empty cobs, but otherwise, don’t be concerned to see corn meal.