Your dog is a picky eater. This is what science says about why he does accept raw food

September 15, 2026
kieskeurige eter

You put the bowl down. Your dog walks over, sniffs it, looks at you and walks away. Two hours later the bowl is still there. Almost every owner of a picky eater knows this pattern, and almost every owner then thinks the same thing: he's spoiled. But in most cases something else is going on. The dog makes a decision based on smell, and that decision is made before he takes the first bite.

Discover Wolfork's raw food

Food that smells the way food should smell

First this: picky or something else?

A dog that has always eaten poorly is different from a dog that suddenly stops eating. With a sudden change, a vet should take a look first. Dental problems, nausea and pain look exactly the same at the food bowl as pickiness. Only once that's been ruled out is it a matter of taste, smell and habit. And that's something you can actually do something about.

Smell determines the choice, before the first bite

Dogs judge their food with their nose, not their tongue. In choice studies, dogs chose their food by smell before eating, and in 89% of the tests they subsequently also ate the most from the portion they had chosen first by smell. So the decision is made at the bowl, not in the mouth.

That's exactly where kibble struggles. Extrusion takes place under high pressure and high temperature, and reduces or alters many natural volatile aroma compounds from meat and fat. For that reason, many kibbles get their smell back after baking: manufacturers spray a layer of flavourings and fats onto the outside of the kibble. That works well enough for many dogs. For a dog with a critical nose, it's the difference between eating and walking away.

Moisture is what makes that smell available

Moisture content and temperature influence how many volatile aroma compounds are released, and thereby how a dog perceives the food. Raw food contains roughly 65 to 75% moisture compared to less than 10% in kibble, which means the aroma hangs in the air immediately when you open the packaging instead of staying bound in a dry matrix. In the scientific review literature, moisture content and texture are therefore consistently among the most important drivers of palatability.

Dogs choose protein and fat themselves

When researchers let dogs of five different breeds compose their own diet from foods with varying compositions, they all ended up at roughly the same point: about 30% protein, 63% fat and 7% carbohydrates on an energy basis. Remarkably consistent, from papillon to saint bernard. Kibble is by definition far removed from that, because most extruded kibbles contain a lot of starch since this is important for the structure. Raw food is close to the profile that dogs choose themselves. In other choice research, dogs moreover showed more interest in animal than in plant-based ingredients.

Kibble

Wolfork raw

  • Aroma applied via coating
  • Less than 10% moisture
  • Starch needed for the structure
  • Fat oxidises after opening the bag
  • Smell fades during use
  • Aroma from the meat itself
  • 65 to 75% moisture
  • No grains or starch
  • Kept frozen, so stable
  • Every portion smells the same

And then the bag that's been open for three weeks

There's another reason why pickiness often starts halfway through a bag. The fat applied to the outside of the kibble oxidises as soon as the bag is open. Fat oxidation is a recognised cause of declining palatability: the smell changes, the dog notices it before you do, and starts to hesitate. That's exactly why the same dog often eats fine during the first week of a new bag, and barely at all during the last week. Frozen raw food doesn't have that problem, because every portion comes fresh out of the freezer.

What does the research say?

This isn't a marketing story. This is what the professional literature says about how dogs choose their food.

Watson et al., 2023

Animals. Review of the drivers of palatability: dogs select their food by smell before consumption, and in 89% of the tests ate the most from the portion they chose first by smell.

Hewson-Hughes et al., 2013

Behavioral Ecology. Dogs of five breeds consistently composed a diet of about 30% protein, 63% fat and 7% carbohydrates on an energy basis when given free choice.

Calderón et al., 2024

Journal of Food Science. Review study on measuring palatability: smell, moisture content and texture are among the determining sensory factors.

Callon et al., 2017

Frontiers in Veterinary Science. Dogs showed significantly more interest in diets based on animal ingredients than in plant-based variants.

Geary et al., 2024

Translational Animal Science. Raw food showed a higher apparent digestibility of protein than extruded kibble (93% versus 82%), with the same pattern for fat.


What the research does not say

We value honesty. There is no controlled study that directly compares raw food with kibble in dogs diagnosed as picky. What there is, is solid research into how dogs choose, and it all points in the same direction: smell, moisture, fat and protein. Also bear in mind that any new food is extra interesting for the first few days. So never judge a switch on the first meal, but after two weeks.

How to approach the switch with a picky dog

We recommend switching over four days: start with 25% Wolfork alongside the current food and build up each day to 50%, 75% and eventually 100%. That gives the gut time to settle. In addition, these four things help specifically with dogs that are difficult eaters:

  • Serve straight from the fridge. Defrost the portion gently in the fridge and serve as soon as it's defrosted. Don't let the food come to room temperature unnecessarily.
  • Stick to twenty minutes. If the bowl is still full after twenty minutes, take it away until the next meal. A bowl that's available all day only makes pickiness worse.
  • Cut out the snacks during the switch. A dog that knows something tastier is coming if he waits, will wait.
  • Don't switch too quickly. With every new flavour the learning process starts over. Give one recipe at least a week.

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