--- title: "Elimination diet for dogs: how to find the allergen step by step" description: "Suspect a food allergy in your dog? See how an elimination diet works step by step and why it is worth starting with a veterinarian." canonical: "https://velipet.com/advice/elimination-diet-for-dogs" lang: "en" publishedAt: "2026-10-14" updatedAt: "2026-10-14" category: "zywienie" --- Itching that will not stop even after a change of shampoo, ear infections that keep coming back, loose stools with no clear cause. If this sounds familiar, you may suspect a food allergy in your dog. Allergy symptoms are easy to confuse with other problems, though, so the first step is a visit to the vet. In this guide we show what an elimination diet looks like when your vet recommends one. :::callout{kind="info"} **In short:** if you notice symptoms in your dog that could point to an allergy, start with a visit to the vet: they will rule out other causes and decide whether an elimination diet is needed. The diet means feeding your dog a single protein that is new to them for 8 to 12 weeks, then gradually bringing back the old ingredients to see which one triggers a reaction. It is the most effective way to find out what your dog is really allergic to. ::: ## How to recognise a food allergy in a dog In dogs, a food allergy most often shows up in the skin and the digestive system. Typical signs include persistent itching, reddened skin, recurring ear infections as well as loose stools or bloating that appear for no obvious reason. These symptoms can be misleading and resemble other health problems, so guesswork alone is rarely enough and the diagnosis is best left to a vet. ## Start with a visit to the vet Before you change your dog's food, book a visit to the vet. Itching, reddened skin or loose stools can have many causes, such as parasites, a skin infection or an allergy to something in the environment, like pollen or dust mites. Your vet will rule these out first. If a food allergy is still suspected, they will suggest an elimination diet, help you choose the protein for it and decide how long it should last. Get in touch with your vet during the diet as well if the symptoms get worse, appear suddenly or do not ease despite the diet. :::callout{kind="tip"} This guide shows what an elimination diet usually looks like, so it is easier to understand your vet's advice and prepare for it at home. It does not replace advice from a vet who knows your dog. ::: ## What an elimination diet looks like step by step If your vet recommends an elimination diet, it usually runs in several stages. 1. **One new protein.** Your vet will help you choose a protein your dog has never eaten before, such as venison, or recommend a food with hydrolysed protein. The less common the meat source, the lower the risk that your dog's body has met it before. If the current food is the suspected allergen, dogs are usually switched straight away, without a gradual transition. 2. **For 8 to 12 weeks, only this one food and water**, with no treats, chews or any extras from the table. Even a small exception can skew the whole trial. 3. **Watching and taking notes.** Write down skin and digestive symptoms, ideally in a simple diary with dates. This makes it easier to spot a real improvement rather than just a good day, and your vet gets concrete information at the follow-up visit. 4. **The challenge test.** If the symptoms have clearly eased, your vet will usually recommend a short return to the previous food. If the symptoms come back, most often within a few days to two weeks, a food allergy is practically confirmed. 5. **Old ingredients one at a time.** Finally, the old ingredients are brought back one after another at a pace agreed with your vet, to see which one makes the symptoms return. This is the stage that finally points to the specific allergen. ## What exactly is a new protein A new protein, also called a novel protein, is a meat source your dog's immune system has not met before, so the risk of it triggering an allergic reaction is much lower. Venison is a classic example. Proteins from closely related species can be similar to one another, though, so the choice of protein is best discussed with your vet. In practice, it is not only the name on the front of the can that matters but the whole ingredient list: a single meat source and no hidden traces of other proteins. We show how to check this on the label in our [guide to reading dog food labels](/advice/how-to-read-dog-food-labels). ## The most common mistakes on an elimination diet - Changing the food on your own, without a visit to the vet, which makes it easy to miss another cause of the symptoms. - Giving treats or table scraps during the diet, which in practice undoes the whole trial, even if it seems like a small slip. - Overlooking "hidden" proteins, for example in flavoured tick tablets, chews or dog toothpastes. Ask your vet about versions without flavourings. - Keeping the diet too short, so the skin and digestive system do not have time to recover fully and the result of the trial is unclear. - Changing several things at once, for example the food and the shampoo at the same time, which makes it hard to tell what actually helped. ## How Veli supports an elimination diet If your vet recommends a diet based on a new protein, at Veli you could consider the [Venison + EntoPro™](https://velipet.com/dogs/venison) recipe. It combines two proteins most dogs have never eaten: venison as the only meat source and EntoPro™, our proprietary bio-protein found in all our recipes. The broth in this recipe is also made from venison, so it does not bring in any other meat. We list the full composition of every recipe on its page, and it is worth going through it with your vet with an eye on what your dog has eaten before. For example, [Salmon + EntoPro™](https://velipet.com/dogs/salmon) also contains 9% chicken offal. When you [build your bundle](https://velipet.com/build-your-box) and tick your dog's allergies, we will leave flavours with those ingredients out of our suggestions. For the duration of the elimination diet, choose one flavour rather than a mix and do not introduce any other new proteins alongside it. ::faq