Badlands RanchSkin & Coat

A plant source of omega-3 fat (alpha-linolenic acid) and fiber, used in about a third of dog foods for coat and stool quality. Dogs and cats convert plant omega-3 to the useful forms inefficiently, so fish oil does the job better. Flax is not a documented common allergen, though some pets tolerate it poorly, most often as loose stool. Fine in a food; not a reason to prefer it over one using fish oil.

Starch from the cassava root, used to bind kibble and as a carbohydrate source, especially in grain-free foods. It is nearly pure starch with little protein, fiber or micronutrients, and it is one of the least likely ingredients to trigger an allergy. A food that leans on tapioca for carbohydrate is getting easy digestibility and little else from it, which is fine as long as the rest of the recipe carries the nutrition.

Oil pressed from whole fish, usually menhaden, herring or sardine, added as the source of the omega-3 fats EPA and DHA. Those fats support skin, coat, joints and brain development, and a food that names fish oil is delivering them in the form pets use directly. It goes rancid quickly, so look for a preservative named alongside it, usually mixed tocopherols. The species is rarely stated, which matters only if your pet reacts to fish.

A grain used as an easily digested carbohydrate. White rice has had the bran removed; it digests fast and is the classic bland-diet starch. Brewers rice is the small broken fragments left after milling, nutritionally the same as white rice despite its reputation as a cheap filler. Rice bran is the outer layer, mostly fiber and oil. Grain allergy is rare in pets; rice is one of the least reactive grains.

A fruit added in small amounts for antioxidants and a bit of fiber. Blueberries are safe for dogs and cats, and the pigments that color them are the same ones linked to antioxidant activity in people. In a complete food they appear well down the list in small amounts, so they are a modest extra and should not decide which bag you buy.