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Black and white spaniel eating from a red bowl

Food Allergies in Dogs

A food allergy is a type of adverse food reaction that if not properly managed can become a serious condition for any dog.

Food allergies in dogs arise when their body confuses dietary proteins found in food with harmful molecules. This results in their body trying to defend itself by enacting an inflammatory response to destroy what it believes are harmful molecules. The result of this defense mechanism is an allergic reaction.

Illustration of a dog walking towards a red bowl

Food Allergies

A food allergy is caused by an adverse reaction to a particular ingredient, typically a protein, in your dog's diet.

Illustration of a dog walking with an environmental allergy

Environmental Allergies

An environmental allergy, also known as an atopic allergy, is an inflammatory disease caused by a genetic predisposition to develop allergies to environmental allergens, such as pollen and dust.

Brown and black dog eating from a bowl

Speak to your vet

If your dog is suffering from a food allergy or environmental allergy, the signs often appear very similar. This can mean it's difficult to tell the difference between the two allergy types.

Learn more about the difference between the two allergies in our article: Are My Dog’s Allergies Caused by Their Food or Environment?

Illustration of food - Royal Canin

What Is Likely To Cause a Food Allergy?

A dog could have an allergic reaction to a variety of foods, whether it's chicken, beef or another ingredient. 

A food allergy simply occurs when a dog's immune system mistakes the molecules in food for something harmful. Allergies to proteins in dog food are more common than allergies to carbohydrates or other ingredients.

How Might a Food Allergy Affect Dogs?

Food allergies are likely to result in a dermatologic reaction; this means issues relating to their skin and coat.

Common signs include:

Illustration of a dog with inflamed skin

Recurring skin infections

Illustration of a dog with inflamed skin

Redness of the skin

Illustration of inflamed intestines

Gastrointestinal upset

Illustration of hairloss in dogs

Hair loss

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Ear inflammation

Want to know more about the potential signs of a food allergy and where they are likely to occur on your dog's body? Keep reading to learn more.

Signs of a food allergy
Illustration of a vet with a dog and its owner - Royal Canin

Supporting Your Dog if They're Suffering From a Food Allergy

If you believe your dog is suffering from a food allergy, always speak to your veterinarian before taking any action.

Your veterinarian will first identify whether it is a food allergy through an elimination diet trial. Once your veterinarian has completed their diagnosis they will be able to advise suitable management options for your dog's food allergies.

Jack Russel with a vet

Tailored Nutrition


If a change in diet is recommended, there are two different options your veterinarian may suggest a hydrolyzed protein diet or a novel protein diet.
Learn more about the difference in diets tailored for food allergies in our article below. 


Understand Dog Food Allergies

Short on time? Boost your knowledge of food allergies in dogs with these short frequently asked questions.

Most retail dog foods contain multiple sources of animal protein and any one of those could be an allergen. If your dog is showing signs of an allergy, your vet may recommend an elimination diet trial to find the cause. This involves feeding a dog a hydrolyzed protein or novel protein diet for several months before reintroducing suspected ingredients to see if they provoke a response. It’s also worth considering that your dog’s allergy may not be caused by food, but by something in their environment, like pollen or dust. Your vet will help you narrow down the potential allergens.

Dermatology diets are specially designed to support dogs who are experiencing a skin condition due to an allergy or a disease. They contain nutrients that can help lessen skin itchiness and inflammation, support healing, and help reduce secondary bacterial infections. Royal Canin, for example, has several dermatology diets and your vet may recommend one of these after assessing your dog’s skin condition.

Dogs with a food allergy may develop skin and/or gastrointestinal issues. Typical signs include inflammation of the skin, itching, redness, sores, and rashes. If they have stomach upset, they may vomit and have diarrhea. Because food allergy signs are indistinguishable from other allergies and some health conditions, it’s best to speak to your vet to determine the cause.

If your dog has allergies, your vet can provide guidance on nutrition and may provide a dietary recommendation based on their clinical signs, breed, age, and overall health condition. Options may include hydrolyzed protein, vegetarian, or novel protein diets.

After an elimination diet trial, your vet may conclude that food isn’t the cause of your dog’s allergies. At that point, they may look at other potential triggers like an allergy to something in their environment (atopy). Additional diagnostic tests may also be needed, as the skin irritation patterns associated with allergies can be found in other health conditions.

Beef and chicken are two of the most common food allergies in dogs.1 If you suspect your dog has an allergy, schedule an appointment with your vet. Depending upon your dog’s signs and condition, your vet may recommend a hydrolyzed protein, vegetarian, or novel protein diet.

Your vet can help establish the cause of your dog’s itchy skin and provide guidance on nutrition. If the itchy skin is caused by an allergy they may recommend a tailored diet that can help reduce the signs of inflammation and support the skin’s natural barrier function. The vet may also recommend topical creams, shampoos, or medications to treat your dog’s skin.

A food allergy is caused by an immune system reaction to something in a dog’s diet, such as a source of protein. Food intolerance is an irregular response to food and doesn’t involve the immune system. Both conditions are types of adverse food reactions and they have similar clinical signs. Your vet will help you determine which one is affecting your dog.

A novel or select protein diet contains a source of meat like rabbit or venison. Because these ingredients are rarely used in retail pet foods, a dog’s immune system is less likely to be familiar with them and may reduce the chance of an allergic response. A hydrolyzed protein diet contains protein that has been broken down at the molecular level into tiny pieces. The protein molecules’ small size makes them less threatening to the immune system, which can lessen the chances of a reaction.

Ask Your Veterinarian About These Products

If your dog has been diagnosed with a food allergy, ask your veterinarian if any of the following products from the Royal Canin Dermatology range are suitable for your dog.

Packshot of Royal Canin Dermatology Dry Diet for dogs

Hydrolyzed Protein HP Dry Dog Food

Recommended by veterinarians, our Hydrolyzed Protein HP Dry helps support healthy skin that may otherwise be prone to sensitivities from proteins found in foods. This diet also helps support healthy digestion with an exclusive blend of fibers and prebiotics.
Packshot of Royal Canin Dermatology Canned Diet for dogs

Hydrolyzed Protein Loaf Canned Dog Food

Available exclusively through veterinarians, our Hydrolyzed Protein Loaf Canned is a wet diet for dogs with food sensitivities. Containing small proteins that are less likely to be recognized by the immune system, this diet also reinforces the skin barrier with essential nutrients to support and protect the skin.
Packshot of Royal Canin Dermatology Dog Treats

Hydrolyzed Protein Canine Treats

Give your dog the occasional treat with our Hydrolyzed Protein Canine Treats. Made with hydrolyzed soy proteins to support the risk of an immune reaction, they also contain B vitamins and amino acids to encourage a healthy skin barrier.


1 Mueller R.S., Olivry T, Prélaud P. Critically appraised topic on adverse food reactions of companion animals (2): common food allergen sources in dogs and cats. BMC Vet Res. 2016; 12:9