Most “freeze-dried vs kibble vs fresh” articles are opinion wearing a lab coat. This one sticks to what controlled studies have actually measured — and says plainly where the evidence stops.
The study that put them side by side
In 2024, researchers published a controlled feeding trial in Translational Animal Science that fed the same ten adult dogs five commercial diets in turn: an extruded kibble, a freeze-dried raw diet, a hybrid freeze-dried diet, a frozen raw diet and a fresh, lightly cooked diet. Every dog ate every diet, which strips out most of the dog-to-dog noise. None of the foods was ours.
| Diet format | Protein digested | Energy digested | Stool per day |
|---|---|---|---|
| Extruded kibble | 82% | 84% | 90 g |
| Fresh, lightly cooked | 86% | 90% | 56 g |
| Hybrid freeze-dried (meat plus grain) | 90% | 92% | 38 g |
| Frozen raw | 93% | 91% | 37 g |
| Freeze-dried raw | 94% | 93% | 40 g |
Two things stand out. The freeze-dried raw diet had the highest protein digestibility of the five, twelve points above the kibble. And dogs on the raw and freeze-dried diets produced well under half the stool of dogs on kibble — which is what “smaller, firmer stools” looks like when somebody actually weighs it.
The caveats matter: ten dogs, one breed, one product per format. It is strong evidence about those diets and a reasonable signal about the formats — not a verdict on every bag on the shelf.
What cooking does to protein
Kibble is made by extrusion: a dough is cooked under heat and pressure — typically 125–150°C — then forced through a die, dried and coated. Heat does useful things: it cooks starch and kills pathogens. It also drives the Maillard reaction, in which lysine, an essential amino acid, binds to sugars and stops being available to the dog.
A 2014 analysis in the Journal of Nutritional Science measured this across 67 commercial pet foods. In extruded dry dog foods, on average about 13% of the lysine had been damaged by processing, and up to 23% in some. The authors flagged that some foods for growing dogs could fall short on lysine once that damage is counted.
Freeze-drying has no cooking step. The food is frozen solid and the water is drawn off under vacuum, so there is no cooking temperature for that damage to happen at.
The fair word on fresh
Fresh, lightly cooked food is good nutrition, and the evidence says so. In a 2018 study in the Journal of Animal Science, lightly cooked fresh diets were the most digestible of the formats tested for most nutrients, with a raw diet highest for fat — and all of them outperformed the extruded kibble. The 2024 study put freeze-dried raw ahead of fresh on protein; the 2018 study put fresh ahead on most measures. The honest reading: both are highly digestible, and both are a clear step up from kibble.
The real differences between fresh and freeze-dried are practical. Fresh is cooked, it is mostly water, it has to be chilled and shipped cold, and it lives in your freezer. Freeze-dried raw is never cooked and lives in the pantry. Here is what shipping that water costs.
Why “at least 20%” keeps coming up
A 2021 study from the University of Helsinki’s DogRisk group, published in the Journal of Veterinary Internal Medicine, looked at what about 4,000 dogs ate as puppies. Owners of dogs whose puppy diet was at least 20% raw food reported fewer allergy-related skin signs in those dogs as adults.
Read that carefully. It is an association from owner questionnaires, not a controlled trial. It studied raw feeding in general, not any brand. And it cannot show that any food prevents or treats allergies. We cite it for a narrower reason: it is one of the few studies to treat raw food as a share of the diet, and it is part of why we talk about a meaningful share of the bowl rather than a sprinkle on top.
What the research does not show
- That food enzymes help digestion. Freeze-drying keeps the enzymes naturally present in raw meat, and cooking inactivates them. But dogs make their own digestive enzymes, and no study has shown that food enzymes make a meaningful difference to a healthy dog. We describe enzymes as a processing difference, not a health benefit.
- Anything about Loyal Saints specifically. None of these studies tested our food. When independent testing of our formulas exists, it will be on our Science Center.
- That raw is risk-free. Freeze-drying removes water; it does not sterilise food. Handle any freeze-dried raw as you would raw meat.
What it means for your bowl
Kibble is the cheapest and most convenient way to feed a dog, and it can be complete and balanced. Fresh and freeze-dried raw are both more digestible in controlled testing. Of the two, freeze-dried raw is never cooked, shelf-stable and — in the one study that measured them side by side — the most digestible on protein.
You do not have to choose all or nothing. We recommend making Loyal Saints at least 20–25% of the bowl, swapped in for the same share of your dog’s current food. See the quarter-bowl standard, or work out your dog’s exact amount.
Sources
- Geary EL, et al. Apparent total tract nutrient digestibility of frozen raw, freeze-dried raw, fresh, and extruded dog foods and their effects on serum metabolites and fecal characteristics, metabolites, and microbiota of healthy adult dogs. Translational Animal Science, 2024. Read the study
- van Rooijen C, et al. Reactive lysine content in commercially available pet foods. Journal of Nutritional Science, 2014. Read the study
- Algya KM, et al. Apparent total-tract macronutrient digestibility, serum chemistry, urinalysis, and fecal characteristics, metabolites and microbiota of adult dogs fed extruded, mildly cooked, and raw diets. Journal of Animal Science, 2018. Summary
- Hemida MBM, et al. Journal of Veterinary Internal Medicine, 2021;35(5):2374–2383 — University of Helsinki DogRisk study of puppy diet and adult skin signs. University summary
Common questions
Is freeze-dried raw more digestible than kibble?
In controlled testing, yes. In a 2024 study, dogs digested 94% of the protein in a freeze-dried raw diet against 82% in an extruded kibble, and produced less than half the stool.
Is fresh dog food better than freeze-dried?
Both are highly digestible and both beat kibble in controlled studies. One study found fresh slightly ahead on most measures; another found freeze-dried raw ahead on protein. The practical differences — cooking, refrigeration, shipping and cost — are bigger than the nutritional ones.
Do the enzymes in raw food help my dog digest it?
That has not been shown. Freeze-drying keeps the enzymes naturally present in raw meat, but dogs make their own digestive enzymes. The measured benefit of freeze-dried raw is its digestibility.
Why do dogs on freeze-dried raw have smaller stools?
Because more of the food is digested. In the 2024 study, dogs fed a freeze-dried raw diet produced about 40 g of stool a day, against about 90 g on kibble.
