Some ingredients that are a good source of fiber are often viewed by the consumer as filler. Soybean hulls and psyllium fiber both fall into this category and have received bad press, when they are a good source of fiber.
The number of recipes using these ingredients is small, and they are found primarily in senior or weight control formulas.
In dry dog food, soybean hulls are included in 0.43 percent of the recipes in this database. Psyllium, listed as psyllium fiber, ground whole psyllium, ground psyllium seed or ground psyllium husk make up another 0.45 percent, so combined the two ingredients are in less than 1 percent of the recipes for dry dog food.
Dry cat food sees higher usage, with soybean hulls in 1.25 percent of the recipes and the combined psyllium listings showing up in 1.23 percent of the recipes. Most of the recipes with soybean hulls has terms such as indoor or weight control in their names or claims.
For more on these products in pet food, read Dr. Greg Aldrich’s Ingredient Issues column, Soybean Hulls: filler or quality fiber source for dogs and cats?