Research & Evidence

Controlled feeding trial comparing animal protein sources in high-protein diets. By-product meal protein quality varied with rendering temperature and starting tissue composition; some by-product meals contain connective tissue that analyses as protein but is poorly digested - supporting the distinction between named meats and vague derivatives.

Peer-reviewed survey of 2,536 dogs. Owner-reported health disorders: 49% conventional meat, 43% raw meat, 36% vegan. Authors note non-dietary confounders may have improved apparent outcomes for raw-fed dogs - useful as a reminder that diet-format claims need controlled data.

Twelve-month controlled study: dogs fed a well-formulated plant-based diet maintained clinical, hematological and nutritional health versus meat-fed baselines. Evidence that formulation quality matters more than ingredient ideology.

Peer-reviewed review of the grain-free/DCM debate. Controlled trials (Leach et al., 30 weeks; Donadelli et al., 26 weeks) found no detectable DCM phenotype or taurine effect from grain-free diets, though authors caution trials were short-term with differing formula quality.

Systematic review (Animals, 2025) testing three marketing claims: that additives/preservatives are harmful, that human-grade ingredients are safer, and that minimal processing is inherently better. Found approved additives showed no measurable increase in adverse outcomes within regulatory limits - an important counterweight we factor in when sizing additive penalties.

Peer-reviewed review (Animals, 2026) of functional ingredients. Antioxidant-rich fruit and vegetable components, omega-3 fish oil and high-quality protein supported renal function and oxidative-stress markers in feeding trials.

Controlled study showing dietary antioxidant supplementation (fruit/berry extracts, green-lipped mussel, omega-3 sources) modulated oxidative-stress markers in working dogs.

Peer-reviewed review (Bauer, J Am Vet Med Assoc 2011; 104 citations) of EPA/DHA evidence in dogs and cats: strongest support for skin/coat, renal, cardiac and osteoarthritis applications, with dose ranges and safety limits.

Peer-reviewed review (Microorganisms, 2023) of probiotic and prebiotic use in dogs and cats: evidence for benefits in acute diarrhoea and antibiotic-associated GI signs, with effects that are strain- and dose-specific rather than generic.

Peer-reviewed factorial derivation of calcium and phosphorus requirements for puppies and adult dogs - the quantitative basis for judging mineral balance rather than label claims.

Peer-reviewed veterinary nursing journal: dietary calcium and phosphorus must be provided together in a ratio of roughly 1.1:1 to 2:1 to maintain hormonal balance, especially critical for large-breed growth.

The human-food parallel for frozen vs shelf-stable (378 citations). Canning's initial thermal treatment causes the largest losses of heat-labile nutrients (vitamin C, B vitamins); frozen products lose fewer because blanching is brief. Nuance the authors stress: canned nutrients are then stable in storage (no oxygen), while frozen degrades slowly over months - so format matters most at production, and 'fresh' that sits for days can fare worse than both.

Part 2 (201 citations): carotenoids, vitamin E, minerals and fibre are broadly similar across fresh, frozen and canned - the meaningful processing losses are concentrated in heat-labile water-soluble vitamins (Part 1), exactly the nutrients retort sterilisation hits hardest.

The reference human-food AGE database (1,091 citations): dry-heat and high-temperature processing multiplies AGE content versus the same food fresh; moist, lower-temperature cooking keeps AGEs low. Direct support for treating retort-sterilised 'shelf-stable fresh' as thermally equivalent to canned/wet food rather than to frozen fresh.

Peer-reviewed: high thermal and mechanical energy in extrusion is reported to cause vitamin losses and decreased amino-acid availability; industrial-scale extrusion measurably altered starch digestibility of a dog kibble.

Peer-reviewed (Animal Feed Science and Technology, 2011): drying extruded diets at 160–180 °C significantly reduced reactive lysine and proline - direct evidence that post-extrusion heat degrades protein quality.

Peer-reviewed lab comparison of 41 commercial dog foods (2026). Fresh foods had significantly more available lysine (56 vs 23 g/kg DM) and less lysine blockage than kibble; advanced glycation end products (CML, CEL) were highest in wet foods; acrylamide was detected only in kibble samples. Disclosure: one co-author is affiliated with Butternut Box; lead lab is Hacettepe University's Food Quality and Safety group.

Controlled feeding trial (2024): frozen raw, freeze-dried raw and fresh diets showed higher amino-acid digestibility coefficients and greater true metabolizable energy than a nutritionally comparable extruded diet.

Among the first studies to show commercial fresh dog foods have significantly greater apparent total tract digestibility (DM, protein, fat, energy) than a nutritionally comparable extruded kibble, regardless of macronutrient composition.