Kirkland Signature Nature's Domain Salmon Meal & Sweet Potato Formula Dog Food

12 ingredients in this list are ones we hold sourced evidence on , and 2 of them are genuinely contested rather than merely unpopular online.

• Potato · ingredient 4ContestedA starchy tuber used as the carbohydrate base in many grain-free foods (it is a vegetable, not a cereal grain). The FDA's open 2018 investigation into diet-associated canine DCM listed potatoes 'in various forms' as main ingredients of interest alongside pulses such as peas and lentils.
• Peas · ingredient 5ContestedA pulse (legume) used in many grain-free foods as a plant protein and carbohydrate source. Peas are central to an open FDA investigation, begun in July 2018, into a possible link between diets high in peas, other pulses, and potatoes and canine dilated cardiomyopathy (DCM); 93% of reported products contained peas and/or lentils.
• Named Meat/Poultry Meal (e.g., Chicken Meal, Lamb Meal) · ingredient 2Well supportedA rendered, water- and fat-reduced concentrate from a named species (AAFCO, e.g., 'chicken meal'). Because most moisture is removed it is a dense protein source (poultry meals commonly around 57-69% crude protein) and it names the species for allergy avoidance.
• Mixed tocopherols (natural vitamin E) · ingredient 7Well supportedA blend of vitamin E forms (alpha-, beta-, gamma-, delta-tocopherol) used as a natural-source antioxidant to slow fat rancidity, commonly chosen as an alternative to synthetic preservatives. EFSA concluded that tocopherol-rich extracts are safe for all animal species and the consumer and are efficacious antioxidants in feed.
• Beet Pulp · ingredient 9Well supportedThe fibrous material left after sugar is extracted from sugar beets, included as a moderately fermentable fiber source (commonly around 5 to 7.5% of the diet). Controlled feeding studies show it supports firm, good-quality stools and short-chain fatty acid production without impairing overall nutrient digestibility, so the 'cheap filler' characterization is not supported by the evidence.
• Fish oil (EPA + DHA omega-3) · ingredient 12Well supportedMarine-source omega-3 fatty acids (EPA and DHA) from fish oil. A randomized, double-blinded controlled trial (Roush 2010) found improved weight-bearing in dogs with osteoarthritis, and a 2022 meta-analysis identified clear clinical analgesic efficacy for omega-3-enriched diets and supplements.