Common Food Allergies in Dogs (and How to Spot Them)

Madelene Hissom · Sep 23, 2021

 Author: Janine DeVault

Just like humans, dogs can experience food allergies. While almost anything can be an allergen, certain ingredients are more common triggers than others. 

Allergic reactions are an immune response a dog’s body takes when it detects a foreign substance. While the substance in question may be harmless, the dog’s immune system somehow decides otherwise and employs defenses against it to fight it off. These defenses manifest in the form of an allergic reaction.    

In this piece, we’ve broken down some of the most common food allergies dogs experience, along with the symptoms to watch for and how to determine the source of your dog’s allergic reaction. 

Let’s dig in! 

Common Symptoms of Food Allergies 

According to the Merck Veterinary Manual, food allergies are most prevalent in Labrador Retrievers, West Highland White Terriers, and Cocker Spaniels. But, of course, any dog can experience food allergies.  

  • Itchy skin, particularly around the face, ears, hindquarters, or paws 
  • Chronic ear infections 
  • Ear odor 
  • Swollen ears 
  • Vomiting 
  • Diarrhea 
  • Weight loss 
  • Dull coat 
  • Hyperactivity 
  • Lethargy 
  • Watery eyes 
  • Skin rash or hives 
  • Red skin, particularly on the belly or ears 

If you notice your dog experiencing any of these symptoms, monitor them closely. Often allergy symptoms seem minor to start, but they can quickly become more severe, causing extreme pain or discomfort for your pup. 

Itching is one of the most common symptoms associated with food allergies in dogs. Chronic itching can cause dogs to scratch or chew obsessively at their skin. This, in turn, can lead to hair loss, skin abrasions, and overall discomfort. 

Ear infections are another common symptom. Most ear infections have early signs, such as ear odor or redness. If the infection develops for too long, the ears may excrete fluid or puss and become uncomfortably itchy.   

Common Allergy Triggers in Dogs   

Your dog may be allergic to any ingredient in their diet, but protein sources are one of the most common triggers. If you notice your dog experiencing allergy symptoms, these items could easily be the culprit.  


Chicken is a prevalent ingredient in all kinds of pet food and treats, but unfortunately, it can cause uncomfortable allergic reactions in some pets. Continuing to eat chicken can cause the allergic reaction to become more severe over time. If you suspect your dog has a chicken allergy, remove it from their diet immediately.   


Beef is present in various types of dog food and treats, from kibbles and wet food to bully sticks, doggy jerky and beyond. Always read ingredients carefully if you know your dog has a food allergy! Some foods may not contain beef directly but instead use beef flavoring, which can also be an allergy trigger. If your dog is allergic to beef, look for another protein source that he might enjoy, such as chicken, lamb, or rabbit.   


Soy is a plentiful and inexpensive protein source, and as such, it often finds its way into dog food. Soy is common in vegetable-based dog food and dog food products marketed as “hypoallergenic.” While soy is not bad for dogs, it can be an allergy trigger. Soy is highly prolific in dog food and treats; read all the labels carefully if your dog is allergic to soy.  


Eggs contain tons of health benefits. In addition to being an excellent protein source, they contain iron, fatty acids, and Vitamin B12, and eggshells contain calcium. These ingredients keep your dog’s bones and teeth strong and their coat shiny. Eggs are found in many popular dog food brands and are frequently used in food toppers and raw dog food diets. 


Just like humans, dogs can be lactose intolerant or allergic to dairy products. It’s worth noting that lactose intolerance is not technically an allergy, but since it still results in eliminating dairy from a dog’s diet, we’ve included it here.  

Common symptoms of lactose intolerance include diarrhea, vomiting, bloating, and flatulence. Similarly, dairy allergy symptoms include itching, hives, vomiting, diarrhea, and any of the other allergy symptoms we covered above. Fortunately, most standard dog foods don’t contain dairy products, so it’s easy to avoid if your dog is allergic. While dairy products like yogurt may be appealing for their probiotic qualities, you can seek out non-dairy alternatives that offer the same benefits.  


Gluten is a protein found in grains like wheat, rye, barley, and more. Grains are a common ingredient in many dog foods and treats, especially low-cost brands, as grains are often used as a “filler” ingredient. The most common symptom of a gluten allergy in dogs is chronic diarrhea. Diarrhea then leads to weight loss, and your dog’s coat may lose its glossy sheen because they cannot retain enough nutrients. Fortunately, gluten-free pet food is easy to find these days.  

How to Identify a Food Allergy 

Given that the symptoms of food allergies are similar regardless of the trigger, determining what your dog is reacting to can be a challenge. 

Usually, your veterinarian will recommend an elimination diet. This means you will have to switch your dog to an entirely new food with ingredients they’ve never had before. Once your dog has stopped experiencing allergy symptoms, you begin adding ingredients from their standard diet back in, one by one. If the allergy symptoms re-occur, you will have your culprit!  

This process usually takes 2 or 3 months to complete.  

The Bottom Line 

Allergy symptoms may be subtle at first, so knowing your dog’s baseline is always essential. Jot down a note any time you notice health irregularities such as excessive scratching, unusual odors, or GI issues.  

While there’s no cure for your dog’s allergies, you can manage them through diet adjustments once you identify them.