Reviews push pet food science beyond functional ingredient claims

Two new review papers are underscoring how fast the “functional nutrition” conversation is evolving in pet food, and how much of it still needs firmer clinical footing. One, published in Veterinary Research Communications, sets out to define functional ingredients, bioactive compounds, and dietary supplements for companion animals. The other, in Animals, narrows in on plant-derived functional ingredients for dogs and cats, cataloging phytochemicals and summarizing proposed mechanisms and reported uses. Taken together, they suggest the field is moving from broad wellness language toward a more structured, compound-level framework. (mdpi.com)

That shift matters because the commercial market has been moving in this direction for years. Pet food labels increasingly highlight ingredients such as berries, fibers, botanicals, algae, omega-3 sources, and probiotics, often with implied benefits for skin, digestion, immunity, or healthy aging. But regulatory systems in the U.S. and Europe still primarily judge pet foods on nutritional adequacy and labeling compliance. FDA explains that “complete and balanced” status is tied to AAFCO nutrient profiles or feeding trials, while AAFCO separately notes that most healthy dogs and cats on an appropriate complete-and-balanced diet generally do not need supplements unless a veterinarian advises otherwise. (fda.gov)

The reviews try to bring more order to that gap between market language and evidence. The Animals paper describes plant-derived ingredients by phytochemical group, including polyphenols, plant extracts, microalgae, omega-3 sources, and cannabinoids, and links them to antioxidant, anti-inflammatory, immunomodulatory, microbiome, metabolic, cardiovascular, and skin effects. A related 2024 review on plant extracts in dogs and cats similarly concluded that compounds such as tea polyphenols, quercetin, curcumin, yucca extract, and tannins are being studied for gastrointestinal, inflammatory, and metabolic effects, though the evidence base remains mixed and ingredient-specific. (mdpi.com)

At the same time, recent data highlight why veterinarians should be cautious about equating ingredient inclusion with clinical benefit. A 2025 PubMed-indexed study of 40 commercial dog and cat kibbles listing blueberries found low levels of quercetin and phenolics, raising questions about whether some “superfood” ingredients appear at physiologically meaningful doses after formulation and processing. Separate work on contaminants in pet feeds has also shown that plant-derived ingredients can introduce unintended compounds, including phytoestrogens and mycotoxins, reinforcing that “natural” or plant-based does not automatically mean simple or risk-free. (pubmed.ncbi.nlm.nih.gov)

I didn’t find many independent expert reaction pieces tied specifically to these two reviews, but the broader industry and regulatory context points in a consistent direction: functional ingredients are of growing interest, yet they sit within a framework that still prioritizes nutrient sufficiency, safe formulation, and evidence-based use. FEDIAF materials emphasize guidance for complete and complementary pet foods and note the role of additives, including probiotics, while AAFCO consumer guidance stresses that supplementation decisions should be made with veterinary input and with attention to total nutrient exposure. That’s not a rejection of bioactives, but it is a signal that the burden is still on manufacturers and researchers to show benefit, safety, and appropriate use. (europeanpetfood.org)

Why it matters: For practicing veterinarians, these reviews are useful less as a green light for functional claims and more as a map of the questions pet parents are increasingly bringing into the exam room. Dogs and cats are not interchangeable nutrition models, and cats in particular have species-specific metabolic constraints that complicate enthusiasm around plant-derived compounds and generalized antioxidant narratives. Clinicians may increasingly need to ask not just what ingredient is present, but in what form, at what dose, with what evidence in the target species, and in what kind of product: complete diet, complementary food, or supplement. (mdpi.com)

There’s also a practical communication issue here. “Functional ingredient” is becoming a bridge term between pet food, supplements, and therapeutic nutrition, and that can blur lines for pet parents. Reviews like these may help standardize terminology, but they also highlight how much of the literature still leans on mechanistic reasoning, rodent or human data, short-term feeding studies, or small companion animal trials. For veterinary teams, that means the safest position remains evidence-first counseling: evaluate the whole diet, the patient’s condition, possible interactions, and whether the claimed benefit is actually supported in dogs or cats. (mdpi.com)

What to watch: The next phase will likely be less about identifying new functional ingredients and more about validating dose-response, processing stability, bioavailability, and clinical endpoints in commercial products, especially as manufacturers try to translate ingredient-level science into label claims and premium formulations. (pubmed.ncbi.nlm.nih.gov)