Blueberries

They are usually present in very small amounts, so rather than adding much nutrition, they mostly give the label a natural look.

Blueberries are a small fruit that cat food makers add, usually dried or as powder, in small amounts. They contain fiber and plant pigments called anthocyanins. We found no FDA or Merck warning about blueberries in cat food, and controlled cat studies on them are scarce. If your cat has diabetes or another medical condition, ask your veterinarian about fruit in its food.

Blueberries add plant antioxidants and a little fiber, along with a fruit name that appeals to shoppers. The amounts in dry food are small, so the effect on the overall nutrient profile is minor. The Merck Veterinary Manual reminds readers that animals require nutrients and not ingredients, which is a useful lens for fruit on a label.

Source: merckvetmanual.com

Not yet in a clear way. Blueberries contain anthocyanins, pigments that act as antioxidants in lab tests, but we found no controlled study showing that the small amount in dry cat food changes health outcomes in cats. Cat foods also add vitamin E and other antioxidants directly, which have defined nutrient roles.

Usually very little. Ingredients are listed in descending order of weight on an as-fed basis, as the Merck Veterinary Manual explains, and blueberries tend to appear near the end of the list after vitamins or minerals. That position suggests a small share of the recipe, though labels do not state the exact amount.

Source: merckvetmanual.com

Pettings gives blueberries 3 out of 5 and lists it as a fruit or vegetable ingredient. It appears on 29 of the 149 dry cat foods we list. Blueberries are one of the more common fruits in the dry foods we track. Each food's page shows how it scores overall.