There are dogs that are very sensitive to grains. There are also dogs that develop allergies that cause numerous health problems. The sensitivity may be just to wheat gluten, but caution dictates a preference to a gluten-free diet. In the year 2007, thousands of dogs died or became seriously ill after eating wheat gluten that was tainted. Owners began to pay more attention to the ingredient labels on dog food. After investigating nutrition labels, you will notice that many of them have wheat or corn gluten as one of the primary ingredients.