Grain-free is one of the biggest talking points in the pet food aisle, and it's easy to come away thinking it's simply the healthier option. The evidence tells a more balanced story. Most healthy dogs digest grains perfectly well, so grain-free isn't an automatic upgrade. It's a targeted choice that suits some dogs and isn't necessary for others.
This guide looks at what the research actually says, so you can decide with confidence rather than following the headlines. We'll cover whether dogs are built to eat grains, which dogs tend to benefit from going without, and what the latest studies tell us about grain-free food and heart health. If you already know grain-free is right for your dog and just want to browse, the grain-free and hypoallergenic collection is here whenever you need it.
The short answer
Here's the honest position before we get into the detail:
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Most healthy dogs don't need grain-free food. They're well equipped to digest grains, and a quality recipe with grains can be every bit as nourishing.
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Grain-free is a targeted choice. It can suit dogs with a confirmed grain sensitivity, or owners who simply prefer a meat-led recipe with different carbohydrate sources.
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It isn't automatically healthier. The right food is the one that suits your individual dog, their life stage and how they feel day to day.
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If your dog is thriving, there's usually no need to switch. A shiny coat, settled digestion and steady energy are good signs their current food is working.
Are dogs even meant to eat grains? What the science says
This is where a lot of the confusion begins, so it's the best place to start. The idea behind grain-free is that dogs are close cousins of wolves and so should eat a meat-heavy, grain-light diet. There's some truth in ancestry, but science has moved on.
Over thousands of years of living alongside us, dogs adapted to digest starch. Researchers who studied the DNA of ancient dogs found that a gene called AMY2B expanded as dogs began living around early farming communities (Ollivier et al., 2016). In plain terms, AMY2B controls how much amylase a dog produces, and amylase is the enzyme that breaks down starch. More of it means a body that's better set up to handle carbohydrates, grains included.
So while dogs are still very much meat-lovers, they're not wolves, and they became well suited to a mixed diet a very long time ago. That's why grains aren't a problem for most dogs, and why going grain-free is about matching a recipe to a particular dog rather than "upgrading" every bowl.
There's an interesting wrinkle worth knowing, too. That same research found the number of AMY2B copies varies quite a bit from dog to dog (Ollivier et al., 2016). In practice, that means some dogs are naturally better at digesting starchy carbohydrates than others. It's part of why one dog can thrive on a grain-inclusive recipe while another seems more settled without grains. There's no single "correct" diet for the species, only the recipe that suits the dog in front of you, which is really the theme of this whole guide.
So which dogs actually benefit from grain-free?
Grain-free earns its place for some dogs, and being clear about who helps you decide whether your dog is one of them.
True food sensitivities are less common than many owners expect. In one widely cited review, confirmed food-related skin reactions turned up in only around one to two of every hundred dogs seen by vets for any reason (Olivry & Mueller, 2017). And where a dog does react to its food, the trigger is more often a protein than a grain (PDSA).
The dogs who may do better without grains tend to share a few signs:
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Digestive upsets that don't settle on their current food
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Itchy skin or a dull, flaky coat
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Recurring ear issues a vet thinks could be diet-linked
Every dog is unique. While the right food can play an important part in supporting their health and happiness, the benefits can look a little different for each dog.
Some owners also simply prefer a meat-led, grain-free recipe on principle, and that's a perfectly reasonable choice too. If your dog is showing any of the signs above, a quick chat with your vet can help put your mind at ease and rule out other causes before you change the bowl. We use the word "sensitivities" rather than "allergies" throughout, because genuine, confirmed food allergies are rare.
You don't have to make all the changes at once. Small steps can make a real difference.
Some owners feed a mix of wet and dry grain-free recipes, or introduce grain-free gradually alongside a dog's current food, which is a gentler way to see how your dog gets on before committing either way. Feeding is rarely a single big decision, and small adjustments often tell you more than a wholesale switch.
If you'd like to go deeper, our guide to the benefits owners notice on grain-free covers what tends to change, and our piece on whether dogs can have food allergies unpacks the sensitivities question properly.
Grain-free and heart health: what the latest research says
You may have seen worried headlines linking grain-free food to a heart condition in dogs called dilated cardiomyopathy, or DCM. That's where the heart muscle weakens and enlarges, so it struggles to pump blood as it should. It's serious, which is exactly why it's worth understanding calmly rather than from a scary headline.
Here's the picture as it stands in 2026. In 2018, the US Food and Drug Administration began investigating a possible link between certain diets and DCM. Years on, it has not established that grain-free food causes the condition, and its own updates say the reports don't provide enough data to prove a causal link (U.S. Food and Drug Administration, 2022).
More recent research has helped sharpen the picture:
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One of the largest studies to date fed 60 healthy dogs four different recipes, both grain-free and grain-inclusive, for 18 months. It found no changes in heart or ultrasound markers pointing to DCM in any group (Morris et al., 2025).
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A 2025 review concluded that where a dietary signal shows up at all, it points towards recipes heavy in legumes such as peas, lentils and potatoes, and to how they may affect taurine, an amino acid that supports heart function, rather than to the absence of grain in itself (Mornard et al., 2025).
Why did legumes come under the spotlight in the first place? One idea researchers have explored is that recipes very high in pulses might affect how much taurine a dog has available, and taurine matters for a healthy heart. That link isn't settled, and plenty of dogs eat legumes with no ill effect, but it's the reason "how much legume" has become a more useful question than "grain or no grain".
The practical takeaway is reassuring and simple: the concern, where there is one, is about recipes dominated by legumes, not grain-free as a category. So if you do choose grain-free, look for a varied recipe led by named meat and fish rather than one leaning heavily on peas, lentils or potato. And if your dog has any heart concerns, this is one to raise with your vet before changing anything.
It's only fair to be clear about the limits of what we know, too. The research so far hasn't proven that grain-free food causes heart disease, and it hasn't pinned down a single ingredient or recipe that's responsible. What it has done is steer sensible feeding towards varied, meat-led recipes and away from bowls dominated by any one ingredient. That's a reasonable standard to hold any food to, grain-free or not.
"Grain-free" doesn't mean grains are bad
It's worth clearing up one last myth, because it drives a lot of unnecessary worry. Choosing grain-free for your dog doesn't mean grains are harmful. For many dogs, grains are a good source of energy, fibre and nutrients, and there's nothing wrong with a well-made recipe that includes them.
Whole grains actually pull their weight in a recipe. Oats, brown rice, and barley provide slow-release energy, fibre that supports healthy digestion, and nutrients such as B vitamins. That's a real contribution, not padding, which is why it also helps to retire the word "filler". No quality ingredient is only a filler. Grains, vegetables and pulses each bring something, and grain-free recipes simply swap grains for other easily digestible carbohydrate sources like potato and peas, chosen for what they add. The real question isn't grain versus no grain. It's whether the recipe as a whole suits the dog in front of you.
If grain-free is the right choice for your dog
If you and your vet decide grain-free suits your dog, the good part is you don't have to overspend to feed well. Our grain-free recipes lead with freshly prepared meat or fish as the number one ingredient, with no artificial colours or flavours, and they're made here in the UK.
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Just 6 keeps things to six key ingredients, which makes it gentle, simple and easy on the tummy for dogs with sensitivities.
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Superfoods add a few functional ingredients like spinach, sweet potato and seaweed, chosen for what they bring to the bowl rather than any miracle claim.
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Our wet dog food range is grain-free too, so you don't have to move to a specialist recipe to feed grain-free. The trays are handy for adding a bit of moisture or tempting a fussier eater.
If you'd like the full rundown of what grain-free food is and how to pick a quality recipe, our guide to what grain-free dog food is walks through it step by step, including how to switch your dog over gradually. And if your dog has a delicate digestion, our food for sensitive stomachs is a good place to look. Whatever you choose, our aim is the same: quality natural ingredients at honest value, no compromise.
References
Mornard, L., Brasileiro, A. C. M., & Marcondes-Santos, M. (2025). Role of diet as a predisposing factor for dilated cardiomyopathy in dogs: A narrative review. Veterinary Sciences, 12(11), 1106. https://doi.org/10.3390/vetsci12111106
Morris, E. M., Stiers, C. A., Hancock, L. B., & Gross, K. L. (2025). Different carbohydrate sources in dog foods supported overall health and cardiac function: An 18-month prospective study in healthy adult dogs. Journal of Animal Science, 103, skaf225. https://doi.org/10.1093/jas/skaf225
Olivry, T., & Mueller, R. S. (2017). Critically appraised topic on adverse food reactions of companion animals (3): Prevalence of cutaneous adverse food reactions in dogs and cats. BMC Veterinary Research, 13, 51. https://doi.org/10.1186/s12917-017-0973-z
Ollivier, M., Tresset, A., Bastian, F., Lagoutte, L., Axelsson, E., Arendt, M.-L., … Hänni, C. (2016). Amy2B copy number variation reveals starch diet adaptations in ancient European dogs. Royal Society Open Science, 3(11), 160449. https://doi.org/10.1098/rsos.160449
PDSA. (n.d.). Food allergies in dogs. People's Dispensary for Sick Animals. https://www.pdsa.org.uk/pet-help-and-advice/pet-health-hub/conditions/food-allergies-in-dog
