Every study, regulation and guideline we cite across this site — in one searchable list, with a link to the original source and to the page where we use it.
AAFCO and FEDIAF set at least 45 g crude protein per 1000 kcal for adult dogs and 56.3 to 62.5 g for growth; higher targets for seniors and working dogs rest on smaller studies.
FDA has not established that diet causes canine DCM and has published no updates since December 2022, while research continues.
Cited on: Nutrition Science →ISAPP sets the scientific definitions. In dogs, the clearest evidence for probiotics is in acute diarrhoea and digestive tolerance; results for other conditions are mixed, and publication bias is a concern.
Eight farmed insect species are authorised in the EU for processed insect protein, and the UK cleared the first cultivated-meat pet food in July 2024.
Raw diets carry higher pathogen risk: one study found Salmonella in 26.2% of raw diets and none of the extruded diets tested. Since January 2025, FDA requires US makers using raw poultry or cattle materials to address H5N1.
In a randomised, double-blind, placebo-controlled trial in 70 senior dogs, an NAD+ precursor plus a senolytic improved owner-rated cognition at 3 months — but objective tests showed no difference, and NAD+ and senescence markers were not measured. In the US, NMN was confirmed as a lawful human dietary supplement in 2025; its status in pet food and feed still needs checking market by market.
In APOP’s 2022 US survey, 59% of dogs and 61% of cats were classified as overweight or having obesity.
A 2026 veterinary review concluded that the human ultra-processed food definition cannot be applied directly to pet food, because complete pet foods must be nutritionally complete by regulation.
Cited on: Nutrition Science →Nutrient profiles are set per 1000 kcal of metabolisable energy (ME). Standard ME equations can misjudge modern foods — one study of 451 foods found errors of 8–12% for wet foods.
Excess matters as much as deficiency. In 2018–19, formulation errors led to US dog food recalls with vitamin D at up to about 70 times the intended level.
Cited on: Formulation Services →Vitamins A, D, E, K, C and folic acid are the least stable in extrusion; one study lost about 26% of vitamin A at preconditioning and about 34% after extrusion and drying.
Heat processing reduces usable lysine; in commercial foods reactive lysine fell as low as 67% of total lysine.
Cited on: Formulation Services →Cats need dietary taurine, and taurine status matters in dogs fed pulse-heavy or grain-free diets.
Cited on: Formulation Services →AAFCO caps calcium at 1.8% of dry matter for foods fed to puppies expected to exceed 70 lb, as excess calcium disturbs skeletal development in giant breeds.
Cited on: Formulation Services →Crude fibre on labels underestimates fibre; total dietary fibre predicts energy digestibility better.
Raw materials vary: in 200 samples of one poultry meal, ash varied by about 20%.
Cited on: Formulation Services →Only 6% of wet and 38% of dry UK foods met all FEDIAF mineral guidelines (2017); in 2025 none of 31 UK dry dog foods met every guideline.
Cited on: Formulation Services →DNA studies keep finding undeclared species — 23 of 40 novel-protein and hydrolysed diets in one study.
Cited on: Formulation Services →Nutrient inadequacies are common in both vegan and meat-based foods; a 2026 review of 54 studies found them in 81.5% of foods examined.
Cited on: Formulation Services →Energy needs vary widely: adult dogs ranged from about 55 to 441 kcal/kg0.75 per day. WSAVA advises treats stay under 10% of daily calories.
Cited on: Formulation Services →A 2026 survey of 126 dog and cat foods found fumonisin B1 in over 94% and more than one mycotoxin in over 92% of products.
Cited on: Testing Validation →In a 2025 survey of 93 products, 8.6% exceeded lead limits; in another study, ingredients such as wheat bran carried higher metal levels.
Cited on: Testing Validation →One study found Salmonella in 26.2% and Listeria monocytogenes in 19% of raw diets, and in none of the extruded diets tested.
Cited on: Testing Validation →Canned cat food lost 17.8% of added thiamine over six months; thiamine deficiency outbreaks have been linked to low-thiamine cat food.
Cited on: Testing Validation →In a 2026 study, 82.3% of 96 products met their declared guaranteed analysis — so nearly 1 in 5 did not.
Cited on: Testing Validation →Peer-reviewed studies now report bisphenols from can linings, PFAS (highest in fish-based foods) and microplastics in commercial pet foods.
A one-bowl test does not yield information about preference, and two-bowl tests are prone to side bias unless bowl positions are alternated.
Cited on: Palatability Feeding Studies →Kennel and home dogs agreed on canned foods but differed on semi-moist and dry foods, linked to feeding history.
Cited on: Palatability Feeding Studies →Expert panels of about 30 animals and in-home panels of about 100 are reported as typical; for cats, two-bowl tests need at least 23 animals for adequate power.
Cited on: Palatability Feeding Studies →In-home digestibility testing needed 9–43 dogs with one day of adaptation and one day of collection; titanium dioxide markers agreed closely with total collection.
Owners’ liking of a dry dog food was driven mainly by kibble colour and appearance, not by what the dog ate.
Cited on: Palatability Feeding Studies →Cats are more selective than dogs, lack a functional sweet receptor, and umami from nucleotides is their main appetitive taste.
Cited on: Palatability Feeding Studies →Retorting cut thiamin in canned cat food by 30.4%, whatever the container; time to reach target lethality ranged from 29.5 to 45.6 minutes by pack size.
Cited on: Pilot Manufacturing →In moist canned cat foods, on average 48.6% of lysine had undergone early Maillard reaction.
Cited on: Pilot Manufacturing →Salmonella stayed detectable on dry pet food for 19 months; E. faecium is a conservative surrogate for validating heat steps.
13 of 84 dried-meat dog treats bought in the UK carried Salmonella; air- and freeze-dried treats had no cooking step.
Cited on: Pilot Manufacturing →HPP at 586 MPa achieved 5-log reductions of Salmonella and STEC in raw pet food, but Listeria was more resistant and results depended on the formula.
Cited on: Pilot Manufacturing →Of 3,691 US pet food recalls from 2003 to 2022, Salmonella caused 23% and chemical causes 32%.
Cited on: Pilot Manufacturing →A 2022 meta-analysis of 72 trials found clear evidence for omega-3s in canine and feline osteoarthritis, but “a very marked non-effect” for chondroitin–glucosamine.
Cited on: Contract Research →Probiotic trials in dogs and cats reporting an effect were far more likely to be published (5 of 7) than those that did not (1 of 5).
Cited on: Contract Research →Veterinary trials with pharmaceutical funding reported positive outcomes 56.9% of the time, against 29.1% with no funding stated.
Cited on: Contract Research →Only 23 of 143 parallel trials in dogs and cats published in 2019 specified their primary outcome.
Common standards now exist for preregistering animal studies, so results can be checked against the original plan.
Cited on: Contract Research →WSAVA advises vets to ask whether manufacturers conduct studies and publish them in peer-reviewed journals.
Cited on: Contract Research →In a January 2026 Packaged Facts survey, half of cat owners agreed that manufacturers sometimes treat cats as “second-class citizens”; fresh cat food remains underdeveloped.
Cited on: Insights →Brands are following the human GLP-1 trend with satiety fibres; one reported dog trial is still awaiting peer review, so dog-specific evidence is pending.
Cited on: Insights →A study of nearly 1,000 UK dog foods found up to a 65-fold spread in greenhouse-gas emissions between products.
Cited on: Insights →Gut–immune and gut–brain science featured strongly at Petfood Forum 2026 and in Purina Institute veterinary programmes.
Cited on: Insights →Palatant suppliers are using formulation and performance data to predict palatability before animal trials.
Cited on: Insights →The EU Packaging and Packaging Waste Regulation entered into force in 2025, with recycled-content targets for plastic packaging from 2030.
Cited on: Insights →In 31 dogs with chronic large-bowel diarrhoea, stool scores rose from 2.6 to 3.8 within one day on a fibre-enriched food; 68% had complete resolution by day 56.
Cited on: Digestive Health →The same trial found the food moved gut metabolism from protein to carbohydrate fermentation and raised beneficial postbiotic metabolites.
Cited on: Digestive Health →A systematic review of 17 dog studies found only a very limited effect of probiotics in acute gut disease and no added benefit over diet in chronic disease.
Dogs fed 0.1% bovine colostrum for 48 weeks had a higher canine distemper vaccine response and higher faecal IgA than controls.
Cited on: Immune Support →Forty dogs fed an antioxidant blend for 16 weeks showed less DNA damage by week 8 and higher vaccine-specific antibodies.
Cited on: Immune Support →Yeast β-glucan kept blood monocytes stable after vaccination in Labradors, but every group reached protective antibody levels.
Cited on: Immune Support →In a randomised, double-blind trial, dogs with osteoarthritis fed a 3.5% fish-oil omega-3 food improved peak vertical force by 5.6% vs 0.4% for controls; 82% vs 38% improved.
Cited on: Joint & Mobility →A systematic review rated omega-3-enriched diets as having the highest strength of evidence in dogs; results for green-lipped mussel were positive but inconsistent.
Cited on: Joint & Mobility →Diets enriched with linoleic acid significantly reduced transepidermal water loss; the ideal omega-6 to omega-3 ratio and dose are not yet agreed.
Cited on: Skin & Coat →International guidelines say oral essential fatty acids may give a small benefit in atopic dermatitis, may take about two months, and are not a sole therapy.
Cited on: Skin & Coat →A high-protein, high-fibre diet reduced voluntary food intake by 51% compared with a high-protein diet in a canine satiety trial.
Cited on: Weight Management →Across 926 dogs in 27 countries, 97% lost weight on high-protein, high-fibre diets (mean 11.4%), but only 7% reached their target weight.
Cited on: Weight Management →In a 2022 US survey, 59% of dogs and 61% of cats were classified as overweight or having obesity.
Cited on: Weight Management →Veterinary consensus recommends urine specific gravity of 1.020 or lower in dogs and below 1.030 in cats, favouring high-moisture foods that keep urine dilute — a recognised factor in calcium oxalate stone risk.
Cited on: Urinary Health →Diets with a struvite relative supersaturation below 1 dissolved struvite stones in a median of 18 days in cats.
Cited on: Urinary Health →In a 28-day trial in 60 dogs, a daily chew significantly reduced plaque, calculus and bad breath and improved gingivitis scores.
Cited on: Oral Care →In a 70-day crossover trial in toy-breed dogs, a daily vegetable chew significantly reduced gingivitis, plaque, calculus and bad breath.
Cited on: Oral Care →In a 56-day randomised, double-blind, placebo-controlled trial in 34 cats, alpha-casozepine significantly improved fear of strangers, contact tolerance and anxiety-related aggression.
Cited on: Calm & Behaviour →A diet with alpha-casozepine and L-tryptophan reduced anxiety signs in an open-field test in cats, but did not reduce fear of an unfamiliar person.
Cited on: Calm & Behaviour →L-theanine increased approach to unfamiliar people in fearful beagles compared with placebo — in a very small study.
Cited on: Calm & Behaviour →In a lifetime study of 48 Labradors, dogs fed 25% less had a median lifespan of 13.0 vs 11.2 years, and late-life disease started later.
Cited on: Longevity & Healthy Ageing →Aged beagles fed 5.5% MCT oil for 8 months performed significantly better on most cognitive tasks.
Cited on: Longevity & Healthy Ageing →A randomised trial in 70 senior dogs found an NAD+ precursor plus a senolytic improved owner-rated cognition, but objective tests showed no difference.
Cited on: Longevity & Healthy Ageing →Great Dane puppies fed three times the recommended calcium developed osteochondrosis-like cartilage lesions and delayed bone maturation.
Cited on: Growth & Reproduction →Puppies given 40 mg DHA per kg per day scored 70.1% vs 62.7% correct on an object-discrimination task.
Cited on: Growth & Reproduction →No findings match. Try another term or topic.
The references behind our articles, case studies and premix guidance, each linked to its source.
We cite the original study, regulation or agency notice — not a summary of it.
A finding is applied only at the dose, species and format it was shown in.
Where evidence is weak, early or from other species, we say so.
Evidence supports nutritional and functional wording, never medical claims.
Our scientists build evidence files for ingredients, formulas and claims — and design studies where the published evidence is not enough.
Every Guires PNL product is formulated to comply with the FEDIAF Nutritional Guidelines and the AAFCO Dog and Cat Food Nutrient Profiles. Neither body issues certificates to manufacturers, so compliance is verified independently against their published standards — and every product comes with a complete documentation package for regulatory submissions in the EU, US, Australia and Asian markets.
How we verify compliance →