WellnessKittles Tuna & Cranberry

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 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look at diet-associated heart disease in dogs, which did not establish a cause; the agency has not asked for any to be withdrawn.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 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 legume used as a carbohydrate and plant protein, common in grain-free foods. Chickpeas supply fiber, folate and protein that lifts the number on the bag without adding meat. Legume-heavy grain-free foods were part of the FDA's 2018 to 2022 look at diet-associated heart disease in dogs, which did not establish a cause. A food that lists chickpeas or peas in the first few ingredients is leaning on plant protein.

A small fruit added mostly for its association with urinary health. Cranberry compounds can make it harder for some bacteria to cling to the bladder wall in laboratory studies, but there is no good evidence that the amount in a pet food prevents or treats urinary infections. At label levels, a small amount well down the list, treat it as a minor fruit that adds a little fiber and antioxidants.

A small oily fish used as a protein and as a natural source of omega-3 fats. Being low on the food chain, herring carries less mercury than tuna. Herring meal is the concentrated, dried form and contributes far more protein per gram than whole herring, which is mostly water. It is a named fish, which helps owners tracking an allergy. Herring oil is listed separately as a fat.

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 plant source of omega-3 fat (alpha-linolenic acid) and fiber, used in about a third of dog foods for coat and stool quality. Dogs and cats convert plant omega-3 to the useful forms inefficiently, so fish oil does the job better. Flax is not a documented common allergen, though some pets tolerate it poorly, most often as loose stool. Fine in a food; not a reason to prefer it over one using fish oil.

Oil pressed from salmon, added for the omega-3 fats EPA and DHA that support skin, coat and joints. It does the same job as generic fish oil but names its source, which helps if your pet reacts to other fish. Like all fish oils it spoils easily and needs a preservative, usually mixed tocopherols. The levels used in food are a modest supplement, well below a therapeutic dose.

Almost always rosemary extract, used as a natural antioxidant to keep fats fresh, usually alongside mixed tocopherols. The amounts are tiny. A persistent internet claim links rosemary to seizures in dogs; there is no published evidence for it at food levels. If your dog has epilepsy, ask your neurologist rather than avoiding foods on this basis alone.

An extract added in tiny amounts for its antioxidant compounds, and in some dental treats for breath. The caffeine content is the only real question, since caffeine is toxic to pets in quantity; the extract is usually decaffeinated or used in amounts too small to matter. There is no evidence the levels in a pet food produce any health effect. It is a marketing ingredient, safe at food levels.