Blue BuffaloBLUE Tastefuls Purées with Salmon

Fish with no species stated. The maker may use whatever is available, so the fish can change between batches. Nutritionally it is a fine protein and often a source of omega-3 fats. The gap is for pets with a known fish allergy, or whose owners are trying to track which protein causes a reaction, because an unnamed ingredient makes that very hard. Named fish such as salmon or whitefish give you that information.

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.

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.

A plant oil with the source unspecified, usually soybean, canola or a blend. It supplies the omega-6 fat linoleic acid, which dogs and cats need for skin and coat. The unnamed source means it can change between batches, which matters little nutritionally since the common vegetable oils are similar. Its omega-3 is the plant form, which pets convert poorly, so a food relying on it will add fish oil or flaxseed for balance.