ApplawsNatural Tuna Fillet Crunchy Treats

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.

A staple of grain-free recipes, supplying starch, fiber and plant protein. Peas were common in the diets examined in a federal investigation into heart disease in dogs; the investigation did not establish a cause and no ingredient was banned. Pea protein high on a list can inflate the protein number with a plant source. Pea allergy is rare. Not a problem, but worth noticing when it appears in several forms in one recipe.

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.

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.