Food Allergies in Dogs

Whether you’ve a super cuddly Labrador Retriever or an energetic Border Collie, choosing the best dog food for your pet is a must. A product with the right nutritional content will keep your dog as happy and healthy as possible. 

But what happens if they become hypersensitive to a certain food type or brand? Food allergies in dogs are surprisingly common, accounting for around ten percent of allergies in dogs. 

Read on for the signs and symptoms of food allergies in dogs and discover what can cause a sudden immune response, even if your pet has been on the same diet for years.

Food allergies in dogs can develop at any age, but the majority of dogs acquire food allergies before the age of three. Repeat exposure to allergens is needed before the immune system reacts. A puppy’s developing immune system can struggle to create the same allergic responses as older dogs, so signs are not always obvious in the younger dog.

When they do occur, symptoms of food allergies in dogs include:

• Hair loss and bald patches 
• Chronic ear infections and inflammation
• Chronic gas
• Coughing 
• Chronically inflamed feet
• Diarrhea 
• Face rubbing
• Head shaking
• Hives 
• Obsessive licking due to itchiness
• Paw biting 
• Poor puppy or adolescent growth
• Skin infections
• Skin rashes
• Vomiting
• Wheezing

Types of food allergies in dogs

Food allergy — An allergy to food is an attempt by the body’s immune system to defend itself against a perceived threat. An allergic reaction doesn’t happen the first time a dog is exposed to the allergen but rather after repeated exposures.

Any food can cause an allergic reaction, but foods such as beef, dairy, chicken, and eggs tend to cause allergies in canines more often than others.

Food intolerance — While a food allergy is the body’s immune system reacting to what it perceives as a threat, food intolerance has no IgE involvement and signs are more mild. An intolerance to a food type is more likely to cause a gastrointestinal response than allergies do.

Additional symptoms, such as a change in the consistency or color of the stools and gurgling sounds from the digestive system, are common with a food intolerance.

Food allergies in dogs are unpleasant, leading pet owners to look up all kinds of alternative dining options. From finding the best plant-based dog food for pets who have a reaction to meat proteins such as chicken, beef and lamb to researching the best grain-free dog food that's free of wheat or gluten, there's no much we wouldn't do for our pets.

But, what's the cause of common food allergies in dogs other than 'it's because of food proteins'?

Put simply, the immune system of dogs sometimes mistakenly believes proteins to be 'harmful' and a defensive response is triggered. As 60-70 percent of a dog's immune system cells reside in the digestive system, food can cause a symptomatic response if it's identified as a foreign invader.

All the immune system is doing on a basic level is attempting to protect the animal. But unfortunately, this can be problematic for both pet and owner.

The process of digestion is designed to break down our foods into their smallest parts, which are known as amino acids. These amino acids are then absorbed by gut cells called enterocytes. When proteins aren't properly broken down during digestion, these enterocytes see them as intruders and attack. Over time, the response of these cells becomes more aggressive and symptoms intensify.

As well as proteins and complex carbohydrates, additives can also be responsible. That's why it's so important to not just grab any dog food and hope for the best. Learn how to read a dog food label and avoid potential triggers for your dog.

When a dog is itchy or has skin disease,, a vet should evaluate the skin, to look for problems such as mites, yeast infections, or signs of disease. 

If these are not detected, a food allergy may be suspected. Food allergy dermatitis in dogs is relatively common but eliminating other conditions is wise to ensure nothing else is going on.

The Importance of an Elimination Diet

In many cases, it might be the entire food family that your pet is reacting to, so switching from a chicken diet to a mammalian source such as rabbit may have a better result than switching to another avian species like duck.

Make sure when you’re researching other food-based products such as the best dental chews for dogs, you’re also abiding by the rules of an elimination diet so that you can really see what’s causing issues for your pet.

If symptoms of food allergies in dogs are indeed coming from a food source, a properly implemented elimination diet will cause them to cease. It can take 8 weeks to see the full effect. It is worth noting that if the dog has a secondary skin infection, they'll continue to be itchy until this has been effectively treated.

 During this time, it’s essential to ensure your dog does not ingest anything other than the food used for the elimination diet. A single treat with the allergen can cause the allergy to resurface.

Sources to avoid include:

• Cow hooves
• Flavored medications (including heartworm preventives) or supplements
• Flavored plastic toys
• Flavored toothpastes
• Pigs’ ears
• Rawhides
• Treats

How Long Does an Elimination Diet Take?

Traditionally, an elimination diet will need to be fed for around 8-12 weeks to determine the cause of your dog's food allergy. However, a 2021 study showed that it may be possible to shorten the length of this diet trial period by administering prednisolone during the first 2-3 weeks of the trial.

During the study, 39 dogs received prednisolone for the first 2-3 weeks of an elimination diet. Medications were then discontinued for 2 weeks before the dogs were then fed their original diet. 

If they relapsed, prednisolone was given for an additional week. Of the 21 dogs determined to have food allergies, 14 of them did not relapse after the medication was stopped, while six dogs had a single relapse and one dog relapsed twice.

So while it's still time-consuming to feed an elimination diet, it may be possible to speed up the process and reach an accurate diagnosis in a much shorter time frame.

It can be disheartening to see your pet suffer. But the good news is, a food allergy in dogs can be monitored and treated. As the elimination diet can take several weeks to reveal the offending allergen, you might need to tackle the existing symptoms head on.

Corticosteroids may be recommended by your veterinarian to reduce swelling and itching, along with antibiotics and/or a medicated wash, to treat any secondary infections.


Once the allergen has been identified, the initial course of action is avoidance of the ingredient. Other supplements, such as Nordic Naturals Fish Oil for dogs and probiotics, may also be recommended after the elimination diet is completed to support the immune system and strengthen the skin barrier.

This will help your dog to handle any accidental exposure to allergens and to prevent the cultivation of new allergies. Of course, supplements should not include the allergen, or the symptoms of food allergies in dogs might return.

Once a dog’s immune system has responded badly to an allergen and created antibodies, that allergen will usually need to be avoided for life. But it’s not all negative news. With so many AAFCO recommended dog foods on the market, you can find a brand that meets your pet’s nutritional needs.

You can even research the best food for fussy eaters and identify a food type that does not contain particular allergens. 

Unfortunately, if your canine has an allergic response to one type of food, they are more likely to develop an allergy to the ingredients in the replacement diet over time as well.

The approach to combat this situation varies within the veterinary profession, with some vets recommending that your pet remain on a single source of dog food for allergies. Others believe that a steady rotation of three to four novel protein sources is optimal. Many will recommend a hydrolysed diet, containing broken down proteins.

Food allergies in dogs can be expensive to treat. If you suspect your dog is at risk of food allergies, start searching for pet insurance today. Wag!’s pet insurance comparison tool lets you compare plans from leading companies like PetPlan and Embrace. Find the best plan for your pet in minutes.