ApplawsTuna Fillet in Broth

A fish used mostly in cat foods, where its strong flavor is the point. Tuna is a good protein and a source of omega-3 fats. Two cautions apply to tuna fed often: it is higher in mercury than smaller fish, and cats can become fixated on it and refuse other foods. Both cautions apply to the cat eating tuna every day, and much less to tuna as one ingredient in a complete food fed in rotation.

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 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.