Vital EssentialsRAW FUSION Frozen Chicken Dog Food

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.

Heart muscle from the chicken, a lean organ meat rich in taurine, iron and B vitamins. Raw and fresh-food makers use it as a natural source of the taurine cats require. It adds protein without much fat and appears mostly in fresh, frozen and freeze-dried foods. For an allergic pet it is still chicken.

The liver of the chicken, used both as a nutrient-dense ingredient and as a flavor. It is rich in vitamin A, iron, copper and B vitamins and most pets find it very palatable, which is why it turns up in treats and as a coating on kibble. Because it is chicken, it counts as chicken for a pet with a chicken allergy, even when it appears far down the list.

A fruit added for fiber, a little natural sweetness and antioxidants. Apple flesh is safe for dogs and cats. The seeds contain a trace of a cyanide-forming compound, which matters for a dog eating whole apples and is far below any concern at the amounts of pomace or dried apple in a food. Apple pomace is what remains after juicing and is mostly fiber. In either form it appears in small amounts and does not change the nutrition of the food in a meaningful way.

A vegetable that contributes a little fiber and beta-carotene and a lot of label appeal. In dry food it is usually present in small amounts well down the list. It is not an allergen of concern and not a meaningful protein or calorie source. Fine to see; not a reason to choose one food over another.

A fruit added in small amounts for antioxidants and a bit of fiber. Blueberries are safe for dogs and cats, and the pigments that color them are the same ones linked to antioxidant activity in people. In a complete food they appear well down the list in small amounts, so they are a modest extra and should not decide which bag you buy.

Broccoli florets or stems, dried and added in small amounts for fiber, vitamins and antioxidants. It is safe for dogs and cats at food levels. Very large quantities contain compounds that can irritate the gut, which matters for a dog raiding the vegetable drawer. A fraction of a percent in kibble is nowhere near that, and it does not change the food's nutrition in any measurable way.

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.