An itchy dog is miserable, and the internet will tell you it is the food. Sometimes it is. Often it is not, and weeks spent switching foods while the real cause goes untreated is time your dog spends uncomfortable.
This article covers the common causes, how a vet tells them apart, and what the research actually shows about diet and skin. Where the evidence is thin, it says so.
Why is my dog's skin itchy?
Itching has several common causes, and more than one can be happening at once. Skin conditions are often complicated and take time to diagnose properly, which is why a vet works through them in order rather than guessing.
Environmental allergy
Sensitivity to things in the environment (pollen, dust mites, mould spores) is among the most common causes of chronic itching in dogs. It often follows a seasonal pattern, and it typically shows on the paws, face, ears, armpits and belly.
Food reaction
A smaller proportion of itchy dogs are reacting to something they are eating. Unlike environmental allergy, it does not come and go with the seasons. It frequently appears alongside recurring ear problems, and sometimes with loose stools.
Fleas and parasites
Flea allergy dermatitis is a reaction to flea saliva, and a single bite can set off days of itching in a sensitive dog. Mites cause intense itching too. Both are treatable and both are easy to miss.
Infection
Bacterial and yeast infections are often secondary (they take hold in skin already damaged by scratching), but they then drive more itching of their own. Breaking that cycle usually needs treatment, not a diet change.
Dry skin
Cold weather, indoor heating, over-bathing and harsh shampoos all strip the skin's natural oils. Dry, flaky skin itches, and it is the one cause on this list that is often genuinely manageable at home.
Common signs to watch for: persistent scratching, licking or chewing (paws especially), redness, fur loss from constant scratching, thickened skin, and recurrent ear infections.
How can I tell if food is the cause?
Properly, and only with your vet: an elimination diet.
Your dog eats a single novel protein and nothing else (no treats, no table scraps, no flavoured medication) for eight to twelve weeks. If the itching improves, the original food is reintroduced to see whether it returns. That rechallenge is the part that actually confirms it, and it is the part people most often skip.
It is slow and it is strict, and it only counts if nothing else passes your dog's lips for the duration. One biscuit from a visitor can invalidate weeks of work.
There is no reliable blood or saliva test for food allergy in dogs. If you are offered one, ask your vet what they make of it first.
We cover this in more detail in how to tell if your dog has a food allergy.
Can changing food help itchy skin?
If the itch is food-driven, yes: removing the trigger protein is what helps, and a novel protein is how that is usually done.
If it is not food-driven, changing food will not fix it. That is the single most useful thing on this page. Environmental allergy, parasites and infection all cause itching, and none of them responds to a new bag of kibble.
The most frequently identified food allergens in dogs, from a 2016 review of published cases confirmed by rechallenge in 297 dogs, were beef at 34%, dairy at 17%, chicken at 15% and wheat at 13% (Mueller, Olivry & Prélaud, BMC Veterinary Research, 2016). Those four sit in a great many dog foods, including some sold for sensitive dogs.
A novel protein is simply one your dog has not eaten before. A dog cannot be sensitised to a protein it has never met, which is why novel proteins are used in elimination diets. That is about exposure, and it does not make a protein incapable of causing a reaction.
What does the research show about insect protein and skin?
Two studies, and both need their limits stated.
A randomised cross-over trial fed eight beagles two diets for 50 days each: one with 29.5% black soldier fly larvae meal, the other with 26% poultry by-product meal, matched for nutritional profile. On the insect diet, transepidermal water loss (the standard measure of how well a skin barrier holds moisture) fell significantly at both the belly and the ear flap, and stratum corneum hydration was higher (Silva Carvalho et al., Archives of Animal Nutrition, 2024).
Lower water loss and higher hydration are the two markers vets use to assess barrier function, so that is a meaningful result. Three caveats, all of which matter: it was measured in healthy dogs, so it did not measure itching or any clinical skin outcome; it ran on eight beagles of one breed; and it was funded by an insect protein producer, with two of its authors employed there.
The second is a small preliminary trial published in 2025, in which eight dogs with diagnosed adverse food reactions, already stabilised on an elimination diet, were fed a black soldier fly diet for four weeks. Their itch scores stayed stable and no significant gastrointestinal side effects were seen. One of the eight was withdrawn at week two after its itching worsened (Srifawattana et al., Veterinary Sciences, 2025).
That trial was small, short, unblinded and uncontrolled, and the authors say larger studies are needed. It shows the diet held those dogs steady, but it does not show it made them better, because the elimination diet had already done that before the trial started.
No controlled trial has compared insect protein against another novel protein in itchy dogs. Anyone telling you insect protein is proven for itchy skin is ahead of the evidence.
What helps dry skin besides diet?
- Bathe less often, and use a shampoo formulated for dogs rather than anything from the human bathroom
- Keep up year-round flea treatment, even through winter
- Brush regularly to spread the skin's natural oils through the coat
- Watch indoor heating in winter, which dries the air and the skin with it
- Treat the ears alongside the skin, since the two usually travel together
When should I see a vet?
Book an appointment if the itching is persistent rather than occasional, if the skin is broken, bleeding, crusted or smells, if there is fur loss, if the ears are repeatedly affected, or if your dog is losing sleep over it.
Go sooner rather than later. Secondary infection is easier to treat early, and the longer a dog scratches the more damage there is to undo.
Where Grub Club fits
All-Day Buffet is a complete dry food using black soldier fly larvae as its only animal protein, at 30% of the recipe, with sweet potato at 15%, potato, whole lentils and pea protein. It contains no chicken, beef, lamb, fish, dairy, wheat or soya, which makes it usable as the basis of a vet-directed elimination trial. Analytical constituents: 28% crude protein, 10% fat, 4% fibre, 354 kcal per 100g.
Skin Saviour is a baked treat with black soldier fly larvae at 20%, on a base of gram, pea, potato and sweet potato flour. 20.9% crude protein, 12.6% fat, 5.2% fibre, 350 kcal per 100g. Up to ten a day alongside a complete diet.
Neither is a prescription diet, and neither has been clinically tested as a treatment for atopic dermatitis, food allergy or any skin condition. If your dog is itchy enough that you are reading this page, a vet should see them.
Shop skin and coat · What the research shows about insect protein and skin · Dog food allergies: what dogs react to
References
- Mueller, R.S., Olivry, T. and Prélaud, P. (2016). Critically appraised topic on adverse food reactions of companion animals (2): common food allergen sources in dogs and cats. BMC Veterinary Research, 12(1), 9. https://doi.org/10.1186/s12917-016-0633-8
- Silva Carvalho, R. et al. (2024). Effect of feeding black soldier fly larvae meal based diet on canine skin barrier function, organic antioxidant defence and blood biochemistry. Archives of Animal Nutrition, 78(2), 159–176. https://doi.org/10.1080/1745039X.2024.2375463
- Srifawattana, N. et al. (2025). Black soldier fly (Hermetia illucens) larvae as a protein substitute in adverse food reactions for canine dermatitis: preliminary results among patients. Veterinary Sciences, 12(1), 68. https://doi.org/10.3390/vetsci12010068
