Hill's Science Diet Adult Perfect Digestion Chicken & Barley Recipe Cat Food

6 ingredients in this list are ones we hold sourced evidence on , and none of them is contested in the veterinary literature.

• Named Meat/Poultry Meal (e.g., Chicken Meal, Lamb Meal) · ingredient 5Well 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.
• Beet Pulp · ingredient 14Well 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 20Well 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.
• Mixed tocopherols (natural vitamin E) · ingredient 29Well 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.
• Flaxseed (ALA omega-3) · ingredient 13NeutralA plant source of the short-chain omega-3 ALA. Dogs convert ALA to the long-chain omega-3s inefficiently: a controlled feeding study (Dunbar 2010) found flaxseed raised serum EPA but produced no measurable DHA.
• Taurine (supplemental) · ingredient 23NeutralA sulfur amino acid that dogs can normally synthesize from methionine and cysteine, so it is not classically essential for them. However, some breeds (e.g., golden retrievers) and some diets are linked to low taurine status and dilated cardiomyopathy: an observational study (Ontiveros 2020) associated non-traditional, largely grain-free diets with taurine deficiency and DCM-consistent echocardiographic changes in golden retrievers, though causation and mechanism remain under investigation.