Open FarmSalmon Dog Biscuits with Oatmeal

A fatty fish used as a protein source and as a natural source of omega-3 fats. Fresh salmon is mostly water, so a salmon meal lower on the list may be contributing more protein. Salmon is a common alternative protein for pets that react to chicken or beef, though fish allergies exist too. Farmed and wild salmon differ in fat profile, and labels rarely say which.

A whole grain used as a carbohydrate and fiber source. Oats are well digested, higher in protein than rice, and contain beta-glucan, a soluble fiber linked to steadier blood sugar. They are a common choice in sensitive-stomach and weight-control foods. Oat fiber is the hull, which is mostly insoluble fiber; oat flour and oatmeal are the whole grain milled. Grain allergy is rare in pets.

A cereal grain used as a slow-digesting carbohydrate. It is high in soluble fiber, especially beta-glucan, and has a lower glycemic effect than rice, which is why it turns up in weight-control and diabetic foods. Pearled barley has had the hull removed, which lowers the fiber somewhat. Barley grass is a different ingredient, a young green shoot used as a vegetable.

A root vegetable used as a carbohydrate source, especially in grain-free foods. It supplies energy, fiber and beta carotene and is well digested by dogs. There is no good evidence it beats rice or oats nutritionally, though it is a reasonable choice for pets that do poorly on grains. Like any starch, a food that lists it high is a starch-heavy food.