Birdie LouieTuna Tango Pillow Treats

The most common protein in pet food, and for dogs one of the most common food allergens, with beef and dairy. If chicken is what your pet reacts to, it hides everywhere: chicken fat, chicken broth, chicken meal, natural flavor. On a label, chicken listed first is weighed with its water still in, so a food leading with fresh chicken often has less chicken protein than one leading with chicken meal. Neither is better; they are different measures.

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look at diet-associated heart disease in dogs, which did not establish a cause; the agency has not asked for any to be withdrawn.

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.

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.

Rendered fat, a concentrated energy source and the main supply of linoleic acid, an essential fatty acid for skin and coat. Rendered fat carries very little protein, so many chicken-allergic pets tolerate it, but not all do, and a strict elimination diet avoids it. Usually preserved with mixed tocopherols. Not a quality concern; a good fat source.

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.

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.