Understanding Allergies in Dogs and How To Help

Does Your Dog Have Food Allergies?

Have you noticed your dog licking, chewing or scratching more than usual? Just like people, dogs are prone to allergies, and finding the source can often be challenging. According to reports, allergies are one of the top 10 reasons why pets visit the veterinarian

In this complete guide to food allergies in dogs, Hannah Godfrey, Tom&Sawyer’s in-house animal nutritionist, answers everything you need to know to help your dog, including:

  1. What is an allergy?
  2. Common causes of allergies in dogs
  3. Dog food allergies vs. food intolerances
  4. Diagnosing dog food allergies with allergy tests
  5. Most common dog food allergies
  6. Treating dog food allergies
  7. What is the best food for allergies?
  8. Quick FAQs: Allergies in Dogs

1. What is an allergy?

An allergy is defined as a state of hypersensitivity to particular substances, or allergens. When a dog comes into contact with an allergen, either through the skin or from consuming a substance, their immune system is activated. This causes the release of histamines, which try to fight off the allergen. This results in common allergy symptoms such as inflammation, reddening of the skin, swelling and itching. Severe allergic reactions can cause anaphylaxis, even in dogs. 

                                                                                    Photo by Rachel Claire

Anaphylaxis in dogs

Anaphylaxis is a severe allergic reaction that can cause vomiting, excessive salivation and drooling, difficulty breathing, swelling of the face and throat, cardiac arrest, a blue tongue and gums, and even death. Anaphylaxis in dogs is generally quite rare, but it is an extreme, life-threatening emergency. If you notice any of the above symptoms, bring your dog to the nearest veterinarian immediately so they can provide your pup with the proper treatment that would include epinephrine and, if needed, assistance breathing.

2. What are the causes of allergies in dogs?

Like people, allergies in dogs can be caused by many external sources. Research suggests that exposure to pesticides, air pollutants, solvents and other toxins can increase asthma and allergies. Allergies are generally grouped into three categories: atopic dermatitis, respiratory allergies and food allergies.

Atopic Dermatitis in Dogs

Atopic dermatitis is the most common type of allergy in dogs, and is generally caused by dust, mold, mites, flea bites, mosquito bites, shampoo, household cleaning products, pollen, carpets and more. Symptoms of atopic dermatitis in dogs include itching and irritation to the skin, persistent licking and chewing, ear infections, redness of the skin or ears, and hair loss.

If your pup suffers from atopic dermatitis, your vet will likely prescribe an anti-inflammatory and anti-itch treatment to help alleviate symptoms.

Respiratory Allergies in Dogs

The least common type of allergies in dogs, respiratory allergies are often seasonal, and are caused by the inhalation of pollen or dust mites. Symptoms of respiratory allergies include itchy, watery eyes, sneezing, and coughing. 

If your pup suffers from respiratory allergies, your vet may prescribe an antihistamine or corticosteroid to help give your dog some relief. 

                                                                                  Photo by Daniel Lincoln

Food Allergies in Dogs

Banfield Pet Hospital State of Pet Health Report, food allergies only affect about 0.2% of dogs. 

Sometimes, adverse food reactions can be misdiagnosed as food allergies. An adverse food reaction is an umbrella term used for food allergies, sensitivities, intolerances, or any negative response to a component of food. 

Symptoms of food allergies occur in response to the immune system, which begins to attack the offending culprit. True food allergies are actually quite rare in dogs and are most often caused by proteins. Unfortunately, unlike food allergies, adverse food reactions are quite common in dogs.

Food allergies in dogs often come with additional conditions. According to the Banfield Pet Hospital State of Pet Health report, “30% of food-allergic dogs and cats are found to have another allergic skin condition. Food allergic pets are also more prone to skin infections - dogs are six times more likely to develop a bacterial skin infection, whereas cats are 15 times more likely.”

Adverse Food and Dog Food Allergy Symptoms:

  • Vomiting
  • Diarrhea
  • Itchy skin 
  • Hair loss
  • Ear infections
  • Sneezing
  • Itchy paws
  • Eye discharge
  • Oily or scaly skin
  • Yeast or bacterial skin infections
  • Increased licking, scratching and chewing

3. Dog food allergies vs. dog food intolerances

Food intolerances and sensitivities are much more common than true food allergies. So, what is the difference between food intolerances and a food allergy? The immune system! A reaction to food due to a food intolerance does not involve the immune system. Symptoms will occur upon the first exposure to a certain food item when it is a food intolerance. 

                                                                                      Photo by James Lacy

Alternatively, a food allergy occurs when the immune system is involved. The immune system begins to attack the culprit and over time and with repeated exposure results in the common signs and symptoms of food allergies. 

food intolerance can often develop into a food allergy when left untreated. Both food sensitivities and food allergies can also increase the likelihood of an irritable bowel disease diagnosis. 

Adverse food reactions often begin at a young age though they can develop in any breed and at any age. 

4. Diagnosing dog food allergies with allergy tests

How can we know if it’s a food intolerance or allergy? Because of the similar signs and symptoms of food intolerances and allergies, they can often be difficult to differentiate. 

There are currently many dog food allergy tests available; however, often these tests are not very accurate. 

That said, food allergies can be diagnosed with the following: 

Skin Patch Testing

Also called intradermal testing, a skin patch test is conducted by your veterinarian, who injects a small amount of a potential allergen into your dog’s skin and then observes the area for redness or swelling.

Blood tests

Blood tests for allergies are done by taking a sample of your dog’s blood, which is sent to a lab that analyzes the blood for specific allergens that are causing your dog’s symptoms. Generally speaking, blood tests for allergies are not very accurate.

Dog Food Elimination Diet

The best way, or the gold standard, to determine a dog food allergy diagnosis is by the most common allergy test: a dog food elimination diet. This test lasts a minimum of 8 weeks, and the diet must not contain any previously consumed ingredients

                                                                    Tom&Sawyer's Kangaroo Recipe

The best elimination trial diets contain single animal or vegetable protein and carbohydrate sources. During this time no treats or snacks should be provided – only the trial diet (and water) should be consumed. After the 8 weeks, the food thought to be causing the allergic reactions is reintroduced. 

If the re-introduction of the food item results in a reaction, then a food allergy can be diagnosed.If it does not result in a reaction, the process would be re-started with another single animal or vegetable protein and carbohydrate source.

5. Most common dog food allergies

Pet owners have reported a number of food allergies in their dogs, but according to this study on cat and dog food allergies published by BMC Veterinary Research, the most common food allergens for dogs are beef, dairy products, chicken, wheat and lamb. Other food allergens, although less common, are soy, corn, eggs, pork, fish and rice. 

If you suspect your dog may have an allergy to one (or more) of these proteins or allergens, try the food elimination diet described above to confirm your suspicions and work with your veterinarian for guidance or additional treatment, as needed.

So, What's Next? Living with dog food allergies

6. Treating food allergies

The best treatment for your pup's food allergies is simply avoiding the food causing the allergy. Since proteins are the most common culprits of food allergies in dogs, novel proteins are often used in pet foods to support food allergies. Novel proteins quite literally mean a new protein. This means that your dog has likely not consumed these proteins before which can limit the chances of seeing an adverse reaction. Consider offering your dog a grain-free or gluten-free option if they have reactions to wheat or other gluten-containing grains. You may also want to offer your dog a grain-free and gluten-free option to reduce exposure to wheat or other grains.                                                    

Common novel protein sources in dog foods are: 

  • Venison
  • Kangaroo
  • Bison
  • Rabbit
  • Quail
  • Alligator 

If your pup is allergic or shows sensitivity to the traditional proteins — such as beef or chicken — you can try introducing one of the novel proteins above. If you do, ensure you introduce only one new food at a time in order to minimize stomach upset or additional reactions.

                                                      Tom&Sawyer's Rosemary Venison Recipe

7. What is the best dog food for allergies?

Generally speaking, we think the healthiest food for your dog is fresh, gently cooked food. Fresh pet food – such as Tom&Sawyer – is made with restaurant quality ingredients, including fresh veggies, antibiotic and hormone-free meats, and non-GMO ingredients. 

Why? Kibble, even kibble labeled hypoallergenic, is highly processed and filled with animal by-products. Kibble is generally composed of a number of ingredients, which can increase potential exposure to allergens. It also often sits on the shelf for long periods of time, compromising its freshness.

Food that's freshly prepared with no artificial fillers and human-edible ingredients also allows you to see exactly what your pup is eating, so you can easily limit ingredients that you might suspect is causing your dog discomfort.

At Tom&Sawyer, we offer multiple meals for pups who may suffer from food allergies and sensitivities. Our Rosemary VenisonKangaroo, and Fisherman’s Best Friend meals offer novel proteins and contain a limited number of ingredients in a complete and balanced recipe to keep your pup thriving.

You can also try a limited ingredient diet for dogs – that is, a diet that usually only contains one protein source and one carbohydrate source. 

If your pup has a grain or gluten allergy we also have a line of grain and gluten-free options, including our Classic Pork StewKangaroo, and Rosemary Venison meals.

All our fresh food for dogs (and cats!) include healthy omega-3 oils and prebiotics to support the immune system, digestion, and help reduce inflammation. Our trained chefs prepare all our meals in small batches with strict quality control measures to ensure purity.

If you have questions about your pet and food allergies, intolerances, or novel proteins, email our Animal Nutritionist at hannah@tomandsawyer.com.

8. FAQs: Allergies in dogs

What are the types of allergies in dogs?

There are three types of allergies in dogs: atopic dermatitis, respiratory allergies, and dog food allergies.

Why does my dog have itchy skin?

Your dog may have itchy skin for a number of reasons, including contact with pollen, dust mites, mold, reactions to flea and bug bites, or allergies to ingredients in their dog food.

How can I tell if my dog has allergies?

Common symptoms of allergies in dogs include vomiting, diarrhea, paw licking, chewing, and scratching, hair loss, ear infections, eye discharge, and more.

What is a dog food allergy?

A dog food allergy is an adverse reaction to certain foods, characterized by diarrhea, vomiting, itchy skin, and other symptoms. Food allergies are usually caused by a protein source, such as beef, chicken, or dairy products. If you think your dog has a food allergy, work with your veterinarian to properly diagnose your pup’s condition and treatment plan.

My dog has allergies, what can I give him?

Some pet owners may give their dogs Benadryl to help with seasonal allergies, food allergies, environmental allergies, and allergic reactions to insect bites. However, we recommend working with your veterinarian to determine the cause of your dog’s allergies before administering medications. 

What is the best dog food for allergies?

Using an elimination diet, first determine what foods your dog may be allergic to. Then, consider feeding your dog limited ingredient foods and novel proteins, such as Tom&Sawyer’s kangaroo or venison recipes. You may also need to feed your dog a gluten- or grain-free diet. 

Can dog food allergies be cured?

Food allergies in dogs cannot be cured. Using the elimination diet described above, the best treatment is avoiding the foods that cause symptoms in your pup. 

Will my dog develop more allergies?

Dogs with food allergies may develop allergies to other foods in the future. And, according to the Banfield Pet Hospital State of Pet Health study, dogs that have food allergies often develop additional skin allergies or skin infections.

Other articles you might like: 
Grain-Free Dog Food vs. Grain-Inclusive: Which is Best for your Pup?
Why Do Dogs Lick Their Paws?
A Guide to Diarrhea in Dogs


Hannah Godfrey
Animal Nutritionist
BSc.H. | MSc. Animal Nutrition


Merck Veterinary Manual

Banfield Pet Hospital State of Pet Health

BMC Veterinary Research