It is no secret that grain-free has become a major portion of the dog food market, but just how pervasive is the grain-free movement?

Using this database of the ingredient decks of dog and cat foods on sale in the United States, we did a thorough analysis of the recipes to determine just how widespread the grain-free movement is in pet food.

In dry dog food, 44 percent of the recipes in the database do not contain grains. These grains include all forms of corn, wheat, rice, soybeans, oats, millet, flax, barley and sorghum.

Grain-free dog food

Of these grain-free recipes, 28 percent have grain-free in their product name or in the formula name. We define names as broken into brand name, product line, formula, and stage. So for example, “Blue Buffalo Basics Grain-Free Adult” has identified itself as grain free in is formula name.

Of the grain-free dry dog food recipes, 50 percent of them contain peas, 23 percent contain chickpeas, and 14 percent contain lentils.

Some brands are more heavily invested in grain-free than others, but 78 percent of the brands producing dry dog food in our database have at least one grain-free formula.

The percentage of recipes using these common alternatives to grains is nearly the same between dry dog and dry cat foods. 

Grain-free cat food formulas

Examining dry cat food, the numbers are similar -- 47 percent of the recipes do not contain grains.

• Of those grain-free dry cat food recipes, 22 percent have grain-free in their product or formula name.
• Of the grain-free dry cat food recipes, 46 percent of them contain peas, 19 percent contain chickpeas, and 14 percent contain lentils.
• Of the brands offering dry cat food in the United States, 73 percent have at least one product that with a grain-free recipe.