Elimination Diet for Dogs: How to Find Food Allergies and Intolerances
Elimination Diet for Dogs: The Gold Standard for Food Allergies and Intolerances
If your dog is itchy, licking their paws, having recurring ear issues, soft stools, diarrhoea, reflux, vomiting, anal gland problems or general “not quite right” symptoms, it is very tempting to blame the food straight away.
And sometimes, food is involved.
But here is the honest bit: food is not always the cause, and guessing your way through endless bags of “sensitive”, “hypoallergenic”, “grain-free” or “single protein” dog food can leave you poorer, more confused, and no closer to an answer.
An elimination diet for dogs is a controlled feeding trial used to identify whether food is causing symptoms such as itching, paw licking, ear problems, vomiting, diarrhoea or digestive upset. It usually involves feeding one carefully selected diet for around 6–8 weeks, then reintroducing foods one at a time to monitor for reactions.
This is why an elimination diet is still considered the gold standard for diagnosing food allergies and food intolerances in dogs.
Not hair tests. Not saliva tests. Not online intolerance panels. Not “I removed chicken and they seemed better for a week”.
A proper elimination diet gives you evidence.
What Is an Elimination Diet for Dogs?
An elimination diet is a temporary, restricted diet where your dog eats only carefully selected ingredients that they are unlikely to react to.
This usually involves one of two approaches:
A veterinary hydrolysed diet, where the protein has been broken down into very small pieces so the immune system is less likely to recognise it.
A carefully chosen novel protein diet, using ingredients your dog has not eaten before ( not the most accurate way)
The aim is to remove the suspected dietary triggers for long enough to see whether symptoms improve. If they do, foods are then reintroduced in a controlled way to see what causes symptoms to return.
That challenge phase matters. Without it, you do not really know whether your dog improved because of the diet, the season changing, medication, reduced treats, fewer scraps, better parasite control or pure timing.
What Dogs Might Benefit from an Elimination Diet?
An elimination diet for dogs may be helpful when there are symptoms that could be linked to an adverse food reaction.
These can include:
Chronic or recurring diarrhoea
Soft stools or mucus in the stool
Vomiting or regurgitation
Excessive wind
Reflux-type signs such as lip licking, gulping or grass eating
Paw licking or chewing
Itchy skin
Recurrent ear inflammation
Anal gland issues
Skin flare-ups that do not settle
Suspected food intolerance or food allergy
However, these signs are not exclusive to food reactions.
Itchy paws, for example, are often linked to environmental allergies such as pollen, dust mites, moulds or grasses. If your dog is licking or chewing their feet, read my blog on why dogs bite their paws:
https://www.thecaninedietitian.co.uk/blog/why-is-my-dog-biting-their-paws
If your dog is itchy all year round, has recurring ear infections, or seems worse in spring and summer, food may only be one piece of the puzzle. My blog on understanding itchy dogs explains why environmental triggers, skin barrier issues and veterinary dermatology support are often needed alongside diet:
https://www.thecaninedietitian.co.uk/blog/understanding-itchy-dogs-top-causes-and-effective-solutions-for-managing-itching-in-your-pet
Food Allergy vs Food Intolerance in Dogs
The phrase “food allergy” gets thrown around a lot, but not every food reaction is a true allergy.
A food allergy involves the immune system reacting to a food protein. In dogs, this may show up as itching, skin inflammation, ear problems or gastrointestinal signs.
A food intolerance does not necessarily involve the immune system. It may be more about digestibility, fat levels, fibre type, ingredient sensitivity, gut health or how well the dog tolerates a particular food.
From an owner’s perspective, both can look very similar. Your dog eats something, then they itch, lick, vomit, have diarrhoea or flare up.
This is why testing through diet history, restriction and careful reintroduction is so important.
Why Are Elimination Diets the Gold Standard?
Elimination diets are considered the gold standard because they test the dog in real life.
They answer the practical question: “Does my dog improve when suspected triggers are removed, and do symptoms return when that food is reintroduced?”
Research suggests that many dogs with cutaneous adverse food reactions improve during a properly controlled elimination diet, and that extending the trial to around 8 weeks improves diagnostic sensitivity. In one critically appraised review, an 8-week restrictive diet identified more than 90% of dogs and cats with cutaneous adverse food reactions.
That does not mean every dog needs exactly the same plan. Some gastrointestinal signs may respond faster. Skin signs often take longer. Dogs with complex histories, steroid use, infections, parasites, pancreatitis, IBD, PLE or other medical conditions need a more tailored approach.
But the principle stays the same: control the diet, track symptoms, then challenge carefully.
Why Food Allergy Tests Are Not Enough
Many owners come to me after spending money on food allergy or intolerance tests. I completely understand why. When your dog is uncomfortable, you want answers quickly.
The problem is that hair, saliva and many blood-based food sensitivity tests do not reliably diagnose food allergy in dogs. They can produce long lists of “red” foods that may not be clinically relevant, leading owners to unnecessarily restrict diets or avoid useful ingredients.
This can make feeding harder, not easier.
The short version? If we want to know whether food is causing symptoms, we need to run a proper elimination diet.
What Can Dogs Eat on an Elimination Diet?
This depends on your dog’s diet history, symptoms, age, health conditions and what they have already eaten.
A true dog food allergy elimination diet should not be chosen because the front of the bag says “sensitive”. It needs to be selected based on your individual dog.
Veterinary Hydrolysed Diet
A veterinary hydrolysed diet contains protein that has been broken down into smaller pieces. This means the immune system is less likely to recognise it and react.
Pros:
Often the best choice for strict elimination trials. Complete and balanced. Useful when your dog’s diet history is messy or they have already eaten lots of different proteins.
Cons:
Can be expensive. Some dogs dislike the taste or texture.
Novel Protein Commercial Diet
A novel protein diet uses a protein your dog has not eaten before.
Pros:
Can work well if the protein is genuinely new to your dog. May be useful for dogs with a simpler diet history.
Cons:
Cross-contamination, vague ingredients and previous exposure can be issues. “Novel” only means new to your dog, not unusual in general.
Home-Cooked Elimination Diet
A home-cooked elimination diet uses carefully selected ingredients, usually one protein and one carbohydrate source.
Pros:
Can be very controlled when planned properly. Useful for some dogs who do not tolerate commercial options.
Cons:
Must be balanced if used longer term. Not ideal without guidance, especially for puppies, large breed dogs or dogs with medical conditions.
Over-the-Counter Sensitive Food
These are foods marketed for dogs with sensitive digestion or skin.
Pros:
Easy to buy. May suit some dogs with mild digestive sensitivity.
Cons:
Usually not suitable for a true elimination diet. They often contain multiple proteins, ingredients your dog has already eaten, or ingredients that are not controlled enough for a proper trial.
For more help understanding hydrolysed diets for dogs, read:
https://www.thecaninedietitian.co.uk/blog/hydrolysed-diets-for-dogs-food-allergies-sensitivities
You may also find this useful: What’s the Best Dog Food for Allergies?
https://www.thecaninedietitian.co.uk/blog/dog-food-for-allergies-and-intolerances
What Does an Elimination Diet Involve?
A good elimination diet has several stages.
Step 1: Take a Full Diet History
Before choosing a food, you need to know what your dog has already eaten.
This includes:
Main meals
Treats
Chews
Dental sticks
Supplements
Flavoured medications
Training rewards
Table scraps
Lick mats
Kongs
Food stolen from other pets
Previous proteins and carbohydrates
This is where many elimination diets fail before they even begin. If your dog has eaten chicken, beef, lamb, salmon, turkey, duck, rice, peas, potato and sweet potato in various foods and treats, choosing a true novel protein becomes much harder.
Step 2: Choose the Right Trial Diet
The safest option for many dogs is a veterinary hydrolysed diet, especially if symptoms are significant or the dog has eaten lots of different proteins before.
Hydrolysed diets are complete and balanced, which matters because elimination trials often run for several weeks. They are also manufactured with better control than many over-the-counter “hypoallergenic” diets.
Novel protein diets can work, but they must be chosen carefully. “Novel” only means new to your dog. Venison is not novel if your dog has eaten venison treats. Duck is not novel if they have had duck chews. Salmon is not novel if they have been on fish-based kibble.
Over-the-counter limited ingredient diets can also be tricky because cross-contamination, vague ingredient sourcing or recipe changes can undermine the trial.
Step 3: Feed the Diet Strictly
This is the boring bit, but it is also the bit that matters most.
During the elimination phase, your dog should eat only the agreed trial diet unless your vet or nutrition professional has approved extras.
That means no random treats. No “just a tiny bit” of chicken. No dental chews. No flavoured supplements. No licking plates. No stolen cat food. No gravy bones from lovely relatives who mean well.
One small addition can muddy the results.
This is not about being strict for the sake of it. It is about getting you answers.
Need Help Choosing the Right Elimination Diet?
If your dog has ongoing itching, diarrhoea, reflux, vomiting, ear issues, paw licking or multiple failed food trials, choosing the right starting point matters.
You can book a consultation with The Canine Dietitian here:
https://www.thecaninedietitian.co.uk/consultations
Or, if you want a step-by-step printable tool to help you track symptoms, flare-ups and food challenges, download the Elimination Diet Diary here:
https://www.thecaninedietitian.co.uk/ebooks/p/elimination-diet-guide-for-dogs
Step 4: Track Symptoms
You need to track what changes.
Useful things to monitor include:
Stool score
Frequency of bowel movements
Vomiting or regurgitation
Grass eating
Lip licking or gulping
Paw licking
Ear redness or discharge
Skin itching
Anal gland signs
Sleep quality
Medication changes
Treats or accidental exposures
This is exactly why I created the Elimination Diet Diary. It gives you a printable structure to track symptoms, flare-ups, food challenges and progress instead of relying on memory.
Step 5: Reintroduce Foods Carefully
If your dog improves on the elimination diet, the next stage is food challenge.
This means reintroducing one ingredient at a time ( usually proteins) and watching for symptoms.
For example, you may challenge with chicken, then return to the safe base diet. Then later you may challenge with beef, lamb or fish, depending on your dog’s history and goals.
This stage helps separate “safe” foods from problem foods. It also stops dogs being unnecessarily restricted forever.
The aim is not to create fear around food. The aim is food freedom with information.
How Long Does an Elimination Diet Take for Dogs?
Most elimination diets are run for 6–8 weeks (not including stabilising on a new food), sometimes longer depending on the dog and the symptoms and if there is a trigger.
Gastrointestinal signs may improve within days to weeks. Skin signs can take longer because inflammation and the skin barrier do not reset overnight.
Some dogs also have infections, parasites, yeast, bacterial overgrowth, IBD, pancreatitis or environmental allergies alongside food sensitivity. In those cases, diet alone may not fully resolve symptoms.
This is why I always recommend working with your vet if symptoms are ongoing, severe, bloody, painful, associated with weight loss, or if your dog is unwell.
Common Mistakes Owners Make
The most common elimination diet mistakes I see are:
Changing foods too quickly
Not stabilising first on a new food
Using a food the dog has already eaten before
Continuing treats and chews
Using “hypoallergenic” foods that are not suitable for a true trial
Stopping after one good week
Not challenging foods afterwards
Blaming grains without evidence
Using allergy test results instead of a structured diet trial
Forgetting flavoured medications or supplements
Making other changes at the same time such as adding in or reducing medications
Not tracking symptoms properly
The other big mistake is assuming every itchy dog has a food allergy. Food can absolutely be involved, but environmental allergies are very common. If your dog is biting their paws, scratching, licking their belly, rubbing their face or having recurring ear issues, diet may need to sit alongside veterinary skin work-up.
Is Grain-Free Food the Same as an Elimination Diet?
No. Grain-free food is not the same as an elimination diet.
Many grain-free foods still contain common proteins such as chicken, beef, lamb or fish. They may also contain multiple carbohydrate sources, legumes, flavourings or ingredients your dog has already eaten before.
Grain is rarely the main issue in dogs compared with animal proteins. Removing grain without a proper plan can make owners feel like they are doing something targeted, when actually the diet may still contain several possible triggers.
An elimination diet is not about following a trend. It is about removing known or suspected triggers in a controlled way.
Can Dogs Have Treats During an Elimination Diet?
Usually, no, not unless the treat has been specifically approved as part of the trial.
This includes:
Dental sticks
Training treats
Chews
Human food
Lick mat toppings
Flavoured supplements
Leftovers
“Natural” treats
Dried meat treats
Even tiny amounts can affect the results.
If treats are needed for training, your dog’s trial food can often be used as rewards. Wet hydrolysed food may also be baked into small treats if suitable, but this should be checked as part of the plan.
Is Chicken a Common Dog Food Allergy?
Chicken is one of the more commonly reported food allergens in dogs, but that does not mean every itchy or sensitive dog is allergic to chicken.
It is also common in dog food, treats and chews, which means many dogs have been exposed to it repeatedly.
The issue is not that chicken is “bad”. The issue is whether your individual dog reacts to it.
This is exactly why a structured elimination diet and challenge phase are more useful than guesswork.
Can I Do an Elimination Diet Without My Vet?
For mild symptoms, some owners may start by improving diet tracking and using a structured guide. However, I would always recommend veterinary involvement if your dog has:
Blood in the stool
Weight loss
Persistent vomiting
Severe diarrhoea
Pain
Lethargy
Recurrent infections
Pancreatitis
IBD
PLE
Kidney disease
Liver disease
A very young age
Complex medical history
Food is only one part of health. A dog with chronic diarrhoea may need faecal testing, blood work, parasite control, imaging or medication before diet can be interpreted properly.
What Happens After an Elimination Diet?
If your dog improves, the next step is not necessarily to stay on the same restricted food forever.
The next step is to identify what your dog can and cannot tolerate.
This may involve:
Reintroducing one protein at a time
Testing specific treats
Building a safe food list
Choosing a long-term complete diet
Moving from a veterinary diet to a suitable commercial or home-cooked plan if appropriate
Keeping a flare-up plan for accidental exposures
A good elimination diet should make feeding easier in the long run, not more restrictive forever.
FAQs About Elimination Diets for Dogs
What is the best elimination diet for dogs?
The best elimination diet for dogs depends on the dog’s diet history, symptoms and health conditions. For many dogs, a veterinary hydrolysed diet is the most reliable starting point. For others, a carefully chosen novel protein diet may be suitable.
How long should my dog stay on an elimination diet?
Most dogs need around 6–8 weeks on the elimination phase. Some dogs with skin symptoms may need longer, while some digestive signs may improve sooner.
Can I give my dog treats during an elimination diet?
Only if the treats have been approved as part of the elimination diet. Most treats, chews and flavoured supplements should be avoided during the trial.
What symptoms can an elimination diet help with?
An elimination diet may help dogs with food-related itching, paw licking, ear issues, vomiting, diarrhoea, soft stools, reflux-type signs, anal gland issues and recurring digestive upset.
Is a hydrolysed diet better than a novel protein diet?
Not always, but hydrolysed diets are often more reliable for strict elimination trials, especially if the dog has eaten many different proteins before or has complex symptoms.
Can I use raw food for an elimination diet?
Raw food is not my preferred option for elimination diets, especially in dogs with gastrointestinal symptoms, immune compromise, pancreatitis, IBD or household members who may be vulnerable to bacteria. A controlled cooked or veterinary diet is usually safer and easier to interpret.
Do allergy tests work for dog food allergies?
Hair, saliva and many blood-based food intolerance tests are not reliable enough to diagnose food allergy in dogs. A properly controlled elimination diet remains the gold standard.
Final Thoughts
Elimination diets are not glamorous. They are not quick. They are not as easy as buying a bag of food that says “sensitive” on the front.
But when done properly, they are one of the most useful tools we have for identifying food reactions in dogs.
They help us move away from guessing, fear and endless food hopping, and towards a plan based on evidence.
If your dog is itchy, gassy, licking their paws, struggling with loose stools, having recurrent ear issues or reacting unpredictably to foods, an elimination diet may be worth exploring.
Start with a full diet history, choose the right trial diet, keep it strict, track symptoms carefully, and reintroduce foods in a structured way.
If you want help choosing the right diet and building a proper plan, book a consultation with The Canine Dietitian:
https://www.thecaninedietitian.co.uk/consultations
If you want a printable tracker to help you monitor symptoms, flare-ups and food challenges, download the Elimination Diet Diary:
https://www.thecaninedietitian.co.uk/ebooks/p/elimination-diet-guide-for-dogs
References
Olivry T, Mueller RS, Prélaud P. Critically appraised topic on adverse food reactions of companion animals: duration of elimination diets. BMC Veterinary Research. 2015.
Olivry T, Mueller RS. Critically appraised topic on adverse food reactions of companion animals: can we diagnose adverse food reactions with in vivo or in vitro tests? BMC Veterinary Research. 2020.
Mueller RS, Olivry T, Prélaud P. Critically appraised topic on adverse food reactions of companion animals: common food allergen sources in dogs and cats. BMC Veterinary Research. 2016.
Mueller RS et al. Critically appraised topic on adverse food reactions of companion animals: prevalence of noncutaneous manifestations. BMC Veterinary Research. 2018.
WSAVA Global Nutrition Guidelines and Nutrition Toolkit.
Today’s Veterinary Practice. Elimination Diet Trials: Steps for Success and Common Mistakes. 2024.
VCA Hospitals. Implementing an Elimination-Challenge Diet Trial in Dogs.
