What are Dog Food Allergies?

Dog food allergies are immune-mediated reactions that occur when a dog’s immune system overreacts to a specific ingredient, mistakenly identifying it as harmful. This exaggerated response targets otherwise harmless substances, leading to symptoms of a food allergy in dogs.

Unlike some health conditions, food allergies in dogs are not linked to age, sex, or breed. Instead, they are thought to result from immune system dysfunctions—particularly within the gut-associated lymphoid tissue (GALT), the mucosal barrier, and the broader systemic immune response (Verlinden et al., 2006).

Early identification of a dog food allergy is essential to prevent complications. If left untreated, these allergies can lead to recurrent ear infections, fungal overgrowth, hair loss (alopecia), and skin infections such as pyoderma—conditions that can significantly diminish a dog’s quality of life.

What are the Most Common Food Allergies in Dogs?

The most common food allergies in dogs are listed below.

1. Chicken Allergies in Dogs

Chicken allergies in dogs occur when the immune system overreacts to proteins found in chicken meat, organs, broth, or by-products commonly used in dog food and treats. This immune response triggers the production of antibodies, leading to signs of food allergies such as itching, redness, swelling, hair loss (alopecia), vomiting, and diarrhea—typically after eating chicken.

To manage a chicken allergy, dogs should be placed on a diet that completely excludes chicken and includes alternative protein sources like beef, pork, lamb, or novel proteins. 

2. Grain Allergies in Dogs

Grain allergies in dogs develop when the immune system reacts to grains such as barley, rice, corn, oats, or sorghum—staples in many dog foods. While these grains provide fiber, nutrients, and carbohydrates, they can cause adverse reactions in sensitive dogs.

Symptoms include itching, redness, hair loss, vomiting, and diarrhea, often after consuming grain-based products. Grain-free dog food can be a suitable alternative, but dietary changes should always be guided by a veterinarian to ensure balanced nutrition. 

3. Beef Allergies in Dogs

Beef allergies in dogs occur when the immune system overreacts to proteins found in beef, including beef meat, by-products, broth, and beef-based dog food or treats. Beef is one of the most common food allergens in dogs, ranking as the leading culprit in a study on the prevalence of allergens in dogs and cats (Olivry, T. et al., 2015).  

When a dog with a beef allergy consumes this protein, the immune system mistakenly identifies it as a threat, triggering symptoms such as itching, redness, swelling, hair loss (alopecia), vomiting, and diarrhea—particularly after consuming large amounts of beef.  

Dogs with a beef allergy should be transitioned to a diet that excludes beef entirely and instead includes alternative protein sources such as pork, lamb, or novel proteins.  

4. Egg Allergies in Dogs

Egg allergies in dogs occur when the immune system reacts to proteins in whole eggs or egg-based ingredients. Ingredients like “dried egg” or “egg products” in commercial dog food can trigger reactions, as can table scraps like bread, pastries, or mayonnaise.
Common symptoms include itching, redness, swelling, hair loss, vomiting, and diarrhea. Egg allergies are manageable through strict dietary oversight and avoiding all egg-containing products.

5. Dairy Allergies in Dogs

Dairy allergies in dogs stem from immune responses to proteins in milk, cheese, yogurt, cream, ice cream, or custards. Cow’s milk is the most common trigger, with allergic reactions tied to specific immunoglobulins (Martín et al., 2004).

Symptoms include gastrointestinal upset—like vomiting and diarrhea—as well as skin irritation such as itching or redness. A dairy-free diet is essential to managing this condition effectively.

6. Soy Allergies in Dogs

Soy allergies occur when a dog’s immune system reacts to soy-based ingredients like soybean meal, soy protein isolate, soy concentrate, or soybean oil, which are frequently used in commercial dog foods.

Affected dogs may experience itching, redness, vomiting, and diarrhea. The most effective management is complete avoidance of soy-based products. 

7. Fish Allergies in Dogs

Fish allergies in dogs are caused by an immune reaction to proteins found in fish meat, oils, or broth. While fish oil is often used for its anti-inflammatory benefits, it can be problematic for dogs with a fish allergy.
Some dogs may react to specific types of fish while tolerating others, making it important to identify the exact trigger. Symptoms include itching, redness, vomiting, and diarrhea—especially after consuming fish in large quantities. Dogs with fish allergies should avoid all fish-based ingredients and transition to diets with other protein sources.  

8. Lamb Allergies in Dogs

Lamb allergies in dogs occur when the immune system overreacts to proteins found in lamb meat, lamb broth, and lamb by-products. While lamb allergies are less common than other food allergies in dogs, they still affect some pets. In a study on the prevalence of allergens in dogs and cats, lamb allergies ranked the lowest (Olivry, T. et al., 2015).  

Signs of a lamb allergy in dogs include itching, redness, swelling, hair loss, diarrhea, and vomiting, particularly after consuming large amounts of lamb. Dogs with a lamb allergy should avoid lamb entirely and be maintained on a diet that includes alternative protein sources such as chicken, beef, pork, or novel proteins.  

9. Corn Allergies in Dogs

Corn allergies in dogs occur when the immune system reacts to corn, which is often used as an ingredient in dog food. Corn, along with other grains, is commonly included in commercial dog food as a source of carbohydrates and fiber.  

Signs of a corn allergy in dogs include itching, redness, swelling, hair loss, diarrhea, and vomiting. To manage a corn allergy, it’s important to carefully read the ingredient list of any dog food product to ensure it doesn’t contain corn. Instead, maintain the dog on foods that use alternative grain sources such as rice, oats, or barley.  

10. Peanut Allergies in Dogs

Though relatively rare, peanut allergies in dogs occur when the immune system reacts to peanuts or peanut-based products, including peanut butter treats.

Fortunately, peanuts are not commonly found in most dog foods, making them easier to avoid. Dogs with a peanut allergy should be maintained on a peanut-free diet to prevent reactions.Dogs with a peanut allergy should be maintained on peanut-free foods to prevent allergic reactions.   

What are the Signs of Food Allergies in Dogs?

The signs of food allergies in dogs are listed below.

1. Pruritus. Itchiness is one of the most common and easily noticeable dog food allergy symptoms. The immune system releases a cascade of immune-mediated reactions which eventually release histamine into the bloodstream which causes the itchiness. Increased exposure to the allergen causes more histamine release and more intense irritation and itching. Pruritus from allergies ranges from mild to severe such as in cases where the dog is no longer capable of sleeping through the night.
2. Erythema. Inflammation from allergies causes an increase in blood flow to the affected area, causing redness. The redness is most often initially noticed at the paws and between the digits, ears, chest, and stomach. Erythema from food allergies ranges from a few spots to covering the entire body from head to toe. 
3. Alopecia. Hair loss is a secondary effect of allergies due to the inflammatory nature of the disease. The chronic inflammation and itching cause damage to the hair follicles and eventually overpower the damage-repairing efforts of the hair shaft. The alopecia ranges from multifocal spots to large areas of the body depending on the severity and duration of which the allergies have been going on. 
4. Chronic Ear Infections. Recurring ear infections are one of the signs of food allergies in dogs. The warm, narrow, and moist environment of the dog’s ear canal is prime territory for bacteria and fungi to proliferate. Allergies aggravate ear infections by causing significant inflammation, swelling, and heat to the ear canal which provides a better environment for infections to happen faster. 
5. Acute Gastrointestinal Signs. Diarrhea, vomiting, flatulence, and bloating are all possible signs of dog food allergies. The food proteins or components react with the gut-associated lymphoid tissues which irritate the mucosal barrier of the stomach and cause poor digestion and adverse food reactions.

Can a Dog Have Multiple Food Allergies?

Yes, dogs can have multiple food allergies, much like humans. Managing a dog with multiple allergies requires extra attention, as pet owners must consider all allergens when selecting food. This often limits the available options. Additionally, dogs that are fed the same food item consistently may become bored with their diet and refuse to eat due to the lack of variety.

How to Know if a Dog has a Food Allergy?

To know if a dog has a food allergy, a diet elimination trial is necessary. This trial typically lasts 8 to 12 weeks, during which the dog is fed a strict diet consisting of ingredients it has never been exposed to before. The veterinarian usually prescribes the specific food to be used and advises against any supplements, vitamins, additives, or meal toppers to ensure the trial remains conclusive.  

The dog must stick to this diet for the full 8 to 12 weeks to observe whether symptoms resolve. If the clinical signs improve within this time frame, a food challenge is then conducted by reintroducing the dog’s previous food. If the dog’s symptoms return within a week of reintroducing the old food, a food allergy is confirmed.  

Can a Dog Allergy Test Kit Diagnose Dog Food Allergies?

Yes, a dog allergy test kit can assist in diagnosing food allergies. However, there is no conclusive evidence to suggest that these test kits are 100% reliable in definitively diagnosing food allergies in dogs. One limitation is the kit’s specificity in determining whether the allergic signs are due to food allergies or other types of allergies, such as environmental allergies, atopic dermatitis, or flea allergies (Bernstein, J. et al., 2019).  

That said, while not foolproof, a dog allergy test kit can still be a valuable tool for identifying specific allergens and guiding the diagnosis process in combination with testing done at a veterinary clinic.

What Allergic Reactions can Happen to Dogs with Food Allergies?

The allergic reactions that can happen to dogs with food allergies are listed below.

1. Urticaria. Urticaria or hives are patches of raised lesions on the skin that are often itchy and uncomfortable. Some hives have a burning sensation when touched leading to increased irritability and discomfort. 
2. Swelling. Swelling is a typical process associated with inflammation. The skin starts to bloat and feel hot to the touch. The swelling ranges from mild to severe with a possibility of causing respiratory anaphylaxis in extremely high exposures. 
3. Rashes. Rashes are a common allergic reaction in dogs. They start as localized or multifocal areas of redness that are itchy and patchy. Mild allergic reactions typically cause short-term rashes that subside after a while. 
4. Pyoderma. Pyoderma is a bacterial infection of the skin that is commonly associated with broken skin exposed to dirt from the environment. The lesions often have a mixture of mucoid and pustular discharge. Chronic itchiness causes increased skin breakage which serves as an entry point for bacteria to proliferate and cause infection. 
5. Folliculitis. The inflammation of the hair follicles causes pustular growths that appear like pimples or pustules. Chronic inflammation causes damage to the hair follicle wherein bacteria become opportunistic and cause infection.
6. Vomiting. Can happen soon after eating the allergenic food.
7. Diarrhea. Loose stools or frequent bowel movements, often happening after eating the allergenic food.
8. Gas & Bloating. Excessive flatulence or stomach discomfort.

When to See a Vet for Dog Food Allergies?

See a vet for dog allergies when signs start to appear. Allergies can often be mistaken for occasional itchiness, particularly in the early stages. Pay close attention if you observe an increase in itching, and take note of the frequency, intensity, and any possible triggers, as this information will be helpful during the veterinary visit.  

More severe signs of food allergies include generalized redness, widespread lesions on the dog’s body, and itching that disrupts normal activities such as walking, sleeping, or eating. Additionally, symptoms like diarrhea or vomiting may indicate a more serious allergic reaction.

How to Treat Food Allergies in Dogs?

The cornerstone of treating food allergies in dogs is the complete elimination of the offending allergen from their diet. This requires strict ingredient management and often involves a veterinarian-guided elimination diet to identify the specific trigger. Once the allergen is pinpointed, pet owners must transition their dog to a diet free from the problematic ingredient.

Veterinarians play a crucial role in creating a personalized treatment plan tailored to the dog’s condition. Prescription anti-itch medications such as Oclacitinib (Apoquel) and Lokivetmab (Cytopoint) are commonly used to relieve itchiness and inflammation. Additional treatments may include skin-supporting supplements containing EPA, DHA, zinc, and antioxidants, as well as antibiotics, antifungal medications, or medicated shampoos to address secondary infections.

For long-term dietary management, veterinarians may recommend:

• Novel protein diets – These use uncommon protein sources like rabbit, kangaroo, ox, or alligator, which the dog has likely never encountered, reducing the risk of allergic response.
  
• Hydrolyzed protein diets – In these diets, proteins are broken down into smaller amino acid chains that are less likely to trigger an immune reaction.
  

Both diet types are designed to support digestive health and reduce allergic flare-ups, making them effective tools for managing food allergies in dogs.

Can CBD Oil Help Manage Dog Food Allergies?

Yes, CBD oil can help manage dog food allergies. Itchiness is a cardinal sign of dog food allergies and is mainly due to histamine release by the overactive immune system. CBD oil for dog allergies interacts with the endocannabinoid system (ECS), which is an intricate system that helps regulate inflammation and immune responses in the body, including itchiness. The ECS interaction helps to soothe the overactive immune system and soothe itchiness in dogs with dog food allergies.  

Can Dog Food Allergies be Cured?

No, dog food allergies cannot be cured. There are currently no medications or procedures to reverse a dog’s adverse reaction to an allergen. Food allergies are only kept at bay through proper management. Strict dietary restrictions must be imposed when dealing with dog food allergies and routine visits to the veterinarian are highly encouraged to keep the treatment/management plan updated to the dog’s needs. 

How Effective are Probiotics for Food Allergies in Dogs?

Probiotics can be beneficial in managing certain aspects of food allergies in dogs, particularly gastrointestinal symptoms. While research on the direct effectiveness of probiotics for dog food allergies remains limited and sometimes conflicting, studies have shown that probiotics help support a healthy gut microbiome, which plays a critical role in digestion and immune system regulation. By promoting balance in the digestive tract, probiotics may reduce inflammation and improve symptoms such as diarrhea, bloating, and discomfort linked to food sensitivities. Pet owners should consult their veterinarian to determine the best probiotic for dogs with food allergies, as formulations vary and should be tailored to the dog’s specific health needs.