ApplawsFish selection in gravy

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.

The familiar white potato, used as a carbohydrate source in many grain-free foods. Potato starch binds kibble; potato protein is a concentrated plant protein that lifts the protein figure on the bag. Cooked potato is safe and well digested. Grain-free foods built on potatoes and legumes were part of the FDA's 2018 to 2022 look at diet-associated heart disease in dogs, which did not establish a cause; the agency has not asked for any to be withdrawn.

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 vegetable added in small amounts for fiber and a little flavor, and in fresh or raw recipes for its water content. It is safe for dogs and cats and appears well down the list, often alongside other vegetables in a blend. It brings almost no calories and only trace nutrients at these levels, so it changes nothing about the food either way.

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 culinary herb added in tiny amounts, usually with a claim about fresh breath. Parsley does contain chlorophyll and some vitamins, but there is no evidence that the fraction of a percent in a pet food changes breath or anything else. It is safe at these levels. It appears on some toxic-plant lists because very large amounts can cause light sensitivity; the pinch in a pet food is nowhere near that.