by Good Dog People October 23, 2022 5 min read

A food allergy or food intolerance is caused by an adverse reaction to a particular ingredient. An allergy or intolerance is an abnormal response to a food or food additive. There are two types of adverse reactions, and they are not the same.

  • Food allergies – adverse reactions in which the immune system is involved
  • Food intolerances - those that occur without an immune component

The term “dog food allergies” is used in error to describe all adverse reactions. The confusion is because both true allergies and intolerances present very similar clinical signs and symptoms. Let’s look at the differences between the two and understand our pets’ needs a little more.

Dog Food Allergies or Food Intolerances: What’s The Difference?

The difference between allergy and intolerance

An allergy is when your dog’s immune system misinterprets the ingredient as an “intruder” (as if it were a virus or bacteria), and the immune system begins to attack it. The side effects of this immune response are inflammation and the symptoms of allergies, most commonly, itchy skin, recurring skin and ear infections, and digestive issues such as diarrhoea. In some rare cases, a severe allergic reaction resulting in anaphylaxis can occur—similar to severe peanut allergies in humans and can be life-threatening. With true food allergies, even a small amount of the food allergen can trigger an adverse reaction.

A food intolerance, on the other hand, does not involve the immune system. It’s when the dog’s digestive system just doesn’t process an ingredient very well, leading to nausea, vomiting, and diarrhoea. An example of food intolerance is lactose intolerance in adult dogs. Every dog is different but with food intolerances, some dogs can tolerate the ingredient in a small amount. An adverse reaction happens only when the dog ingests the ingredient in larger quantities.

Many canine experts and veterinarians believed that true food allergies are not as common as people think. What most people believed to be dog food allergies are actually dog food intolerances. A 2016 study published in the journal BMC Veterinary Research found that true food allergies occur in only 1%–2% of dogs.  

Dog Food Allergies or Food Intolerances: What’s The Difference?

Causes of dog food allergies and intolerances

The symptoms of both can be very similar. It’s difficult to tell them apart. The best advice is to go to your vet. If your vet suspects food allergies, he or she may propose food allergy testing to determine the ingredient that is causing the adverse reaction. The best way to treat an allergy is avoidance of the allergen.

Typically, it’s the protein in a dog’s food that triggers an allergy. The ingredients that are most often associated with true allergies in dogs are beef and chicken—not because these foods are especially allergenic but because they are the most prevalent protein found in commercial dog food. It is a known fact that the longer the exposure to a particular protein, the more likely a dog is to develop an allergy to that protein. For dogs not suffering from any form of food allergies, it is wise to rotate your dogs’ dietary protein every few weeks. Feeding your dog the same dog food for many months or years can lead to problems.

Adverse reaction due to food intolerance is typically a one-off incident. For example, a lactose intolerant dog is unable to digest lactose and may suffer from bouts of diarrhoea or upset stomach (tummy ache, gas, nausea) when he consumes milk. Symptoms of tummy upset will subside when you stop feeding milk to the lactose intolerant dog. However, if you regularly feed the dog the offending ingredient, he will experience chronic digestive issues. If left unresolved, poor digestive health may lead to other more serious issues like nutritional deficiencies, chronic diarrhoea, behavioural changes, weight loss, and dry and itching skin.  

Dog Food Allergies or Food Intolerances: What’s The Difference?

Managing dog food allergies and intolerances

For dogs currently experiencing food intolerances or allergies, avoiding the offending ingredient is the best treatment plan. In this situation, stick to a single protein, limited ingredient dog food and choose novelty protein. Novelty protein is a protein source that’s new to your dog, one your dog has never eaten before and therefore hasn’t developed an allergy to.

Here’s a single protein, limited ingredient air-dried dog food with venison - ZIWI Peak Daily Dog Air Dried Venison Dry Dog Food (Improved). This pet food is highly digestible, easy on your pet’s sensitive digestive system.

For dry dog kibble, try the Carna4 Easy-Chew Quick Baked Air Dried Venison Recipe Dry Dog Food. This is another nutrient-dense, highly digestible dog food and ideal for dogs with a sensitive digestive system. Do take note that Carna4 contains multiple protein sources. Check the ingredient and choose the protein that your dog is not allergic to. For Carna4 Dry Dog Food, check out our Try & Buy section for a trial pack before making the full purchase. Here’s the Try & Buy trial pack for the venison flavour.

Depending on your dog’s condition, your vet may even prescribe hypoallergenic dog food.  

Dog Food Allergies or Food Intolerances: What’s The Difference?

There’s nothing much that can be done with a true food allergy except to avoid the allergen. However, in the case of dog food intolerances, adding a probiotic supplement or digestive enzymes for dogs may help. Helping your dog improve his digestive system can sometimes mitigate the symptoms of food intolerance. Try the NaturVet Digestive Enzymes Prebiotics Plus Probiotic Powder Cat & Dog Supplement. It contains digestive enzymes to aid in your dog’s food digestion and pre and probiotics for better nutrient absorption.  

Not all itching skin is caused by food allergies/intolerances

Most pawrents will equate itchy skin to food allergies but this may not be always true. For example, some dogs are allergic to flea saliva, and fleabites can result in itching skin. Environmental allergens such as dust, mold, or even harsh chemical cleaners may cause skin allergies and itching in dogs too. When you see your dog scratching, do not assume that it’s food allergies. It can be due to other environmental allergens. Itching and scratching due to an environmental allergen can be quickly resolved by removing the offending allergen.

Using an anti-itch spray like this Tropiclean Oxymed Anti-Itch Medicated Spray (Spot Treatment) For Cats & Dogs may help to calm skin inflammation and reduce itching. Bathing your dog with a natural deep cleansing shampoo to remove irritants from your pup’s skin may help to reduce itching too. Here’s an all-natural, deep cleansing shampoo for dogs with red, itchy, irritated skin - Natural Dog Company Unscented Itchy Dog Shampoo For Dogs.  

Dog Food Allergies or Food Intolerances: What’s The Difference?

Finally, don’t forget the dog treats, supplements, and dental chews, as all these may have ingredients that your pet could react to. When trying to avoid certain ingredients in the main diet you will need to look at the composition of these items too.  









Katherine Khoo
Katherine is a Pet Nutrition Specialist and GDP’s Pet Wellness Advisor. She is committed to helping pet owners make informed dietary and lifestyle choices in nurturing healthy pets. Katherine is also a practicing Nutritional Therapist (human nutrition) and has been helping hundreds of clients to heal naturally with nutrients.

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