How To Tell If A Dog Has Food Allergies: All You Need to Know

How To Tell If A Dog Has Food Allergies

Canine Bible is reader-supported. We receive affiliate commissions via some of our links. This doesn’t affect rankings. Learn more.

This content was reviewed and fact-checked by veterinarian Dr. Aukse Caraite, DVM.

Your dog is vomiting, experiencing abdominal pain, keeping you awake, and harming their well-being. It’s frustrating for you and uncomfortable for them. While your first thought might be a food allergy, true food allergies are less common than you might think. Often, what is mistaken for a food allergy is actually a food sensitivity or intolerance. This confusion is frequent among both dog owners and veterinarians.

Understanding the difference between food allergies and sensitivities is essential for accurately diagnosing and effectively treating your dog’s condition. Proper identification can greatly improve their quality of life.

What Are Dog Food Allergies?

Dog food allergies are immune system responses to specific proteins or ingredients in a dog’s diet. When dogs consume an allergen, their body mistakenly identifies it as harmful, triggering an allergic reaction. Identifying and managing these allergies is crucial for maintaining a dog’s health and comfort. Food allergies can appear at any age, and dogs can even develop allergies to foods they have eaten for years. Dog food allergies are estimated to affect 1% to 2% of the dog population and account for 10% of all dog allergies.

Causes of Food Allergies In Dogs

Dogs’ food allergies are predominantly caused by food allergens such as proteins, especially dairy products, beef, lamb, chicken, chicken eggs, soy, or gluten (from wheat). While proteins are the most common source of allergens, virtually any food ingredient can produce an allergy. Substances like additives, colorants, and preservatives can also be responsible.

Dog Food AllergenPercentage of Dogs With Reported Reaction
Dairy Products17%
Source: BMC Veterinary Research

How to Tell If Your Dog Has Dog Food Allergies?

There are three ways to tell if your dog has food allergies.


Monitoring and documenting your dog’s symptoms is vital in identifying food allergies. A symptom diary is an effective tool for tracking your dog’s health and behavior. By consistently recording details such as the type and severity of symptoms, the time of onset, and any potential triggers, you can provide valuable information to your veterinarian. This information can help pinpoint specific allergens and determine the best action for managing your dog’s condition.

These are the most common symptoms associated with food allergies in dogs:

  • Gastrointestinal and digestive issues
  • Skin issues (Itching, hot spots, skin rashes, scaly and oily skin & a gamut of skin reactions)
  • Vomiting
  • Diarrhea
  • Mucus in stool
  • Straining to pass stool
  • Abdominal pain
  • Swollen face
  • Ear or paw infections

Secondary symptoms can occur, such as hyperactivity, weight loss, lack of energy, and even aggression. One study showed that non-allergic dogs have around 1.5 bowel movements per day, whereas some dogs with food allergies may have 3 or more per day.[1] So, if you notice your pup going potty more frequently than normal, it may be a sign of a food allergy. Another study ranked the parts of the body most often involved in itching related to food allergies as follows:

  • Ears (involved 80% of the time)
  • Paws (61%)
  • Inner thigh/belly (53%)
  • Eye or front leg area (33%).

Elimination Diet

The elimination diet is the gold standard for diagnosing food allergies in dogs. This approach involves systematically removing potential allergens from your dog’s diet and monitoring for any changes in symptoms. It involves exclusively feeding your dog a hypoallergenic diet containing novel ingredients—such as proteins and carbohydrates they have never eaten—for eight to twelve weeks. No other foods, treats, or flavored medications must be given during this time to avoid potential allergens. The goal is to observe whether symptoms, such as itching or gastrointestinal issues, improve. After the initial phase, suspected allergens are gradually reintroduced one at a time, with careful monitoring for any recurrence of symptoms. This process helps identify specific food triggers and enables effective management of your dog’s diet to prevent future allergic reactions.

Dog Food Allergy Testing

In addition to dietary trials, dog food allergy tests such as blood tests and allergy panels can provide supplementary information. These tests measure the presence of specific antibodies that the dog’s immune system produces in response to certain allergens. Although blood tests can indicate potential food allergies, they are not as definitive as elimination diets and food trials. However, they can be useful in conjunction with other diagnostic methods to comprehensively understand your dog’s food allergies.

Identifying food intolerances is useful in diagnosing food allergies because it helps differentiate between the two conditions, which have overlapping symptoms but different underlying mechanisms. Recognizing food intolerances can streamline the diagnostic process for food allergies. At-home dog food intolerance tests like the 5Strands food intolerance test (which can test for up to 255 ingredients) can be valuable in this diagnostic journey. These tests allow pet owners to gather preliminary data about their dog’s reactions to various foods. This information can guide more targeted elimination diets and reintroduction phases, making diagnosing food allergies more efficient and accurate.


Once you’ve identified the food allergen(s), the only treatment is to avoid the food allergen(s). In many cases, veterinarians prescribe hypoallergenic, hydrolyzed, or limited-ingredient diets that can be fed for the rest of your dog’s life. Your veterinarian can discuss the best choices for your pet based on what ingredients your dog is allergic to. Sometimes, commercial dog food containing the right ingredients is unavailable, or your dog will not eat them. If so, you may need to carefully prepare a home-cooked diet designed by a board-certified veterinary nutritionist.

Dog allergy medications can support the management of food allergies, particularly when symptoms are severe or persistent. While these medications can be highly effective, they should be used under veterinary supervision to avoid potential side effects and ensure appropriate dosages.

Here are some of the best food allergy medicines for dogs.

7 Ways to Prevent Food Allergies In Dogs

While there is no sure-proof way to prevent food allergies, anything that creates an unbalance in your dog’s digestive system (gut) can ultimately cause allergy development over time—promoting a healthy mucosal barrier and ensuring adequate nutrition since puppyhood is key in keeping food allergies at bay.

Preventing food allergies in dogs involves a combination of proactive measures, careful dietary management, and ongoing monitoring. While it may not always be possible to prevent food allergies entirely, several strategies can reduce the risk and help maintain your dog’s overall health.

  • Introduce new foods gradually: Introducing new foods slowly allows you to monitor your dog for adverse reactions.
  • Rotational diets: Implementing a rotational diet can help prevent the development of food allergies. This involves regularly switching between different protein and carbohydrate sources, reducing the likelihood of your dog developing sensitivities to specific ingredients over time.
  • Fresh diet: Consider a diet based on fresh ingredients such as homemade dog food, raw dog food, or even vegan dog food. These foods are not processed effectively helping your dog avoid common allergens from chemicals in processed dog food.
  • Avoid Over-Processed Foods: Highly processed foods can contain additives, preservatives, and artificial ingredients that may trigger allergies. Opt for natural, minimally processed dog foods when possible.
  • Dog Gut Health Test: Regularly conducting a dog gut health test can help in the early detection and prevention of food allergies. By assessing the balance of bacteria in your dog’s digestive system, these tests can identify imbalances or dysbiosis that may predispose your dog to food allergies.
  • Read Labels Carefully: Always check the ingredient lists on dog food packaging to ensure they do not contain known allergens or unidentified by-products that could trigger allergic reactions.
  • Probiotics: Including probiotics in your dog’s diet can support a healthy digestive system and immune function. A balanced gut microbiome may reduce the likelihood of developing food allergies.
  • Supplements: Omega-3 fatty acids and other supplements can help maintain skin health and reduce inflammation, potentially lowering the risk of allergic reactions.
  • Limit Human Food: Many human foods can cause allergies in dogs. Avoid feeding your dog table scraps or foods intended for human consumption, especially those known to be common allergens.

Dog Food Intolerance Vs Dog Allergies: What’s The Difference?

Dogs can also suffer from food intolerance, different from food allergies. Food allergies in dogs occur when the body’s immune system responds to a substance previously exposed (i.e., proteins or other allergens), and the body has created antibodies. Food intolerance or sensitivity refers to all other non-immunologic adverse responses to food; they are much more common. The symptoms for both can be very similar.

Differentiating Food Allergies From Other Conditions

Understanding the differences between food allergies and other types of allergies in dogs is essential for accurate diagnosis and effective management.

  • Food Allergies
  • Skin Allergies
  • Seasonal Allergies
  • Environmental Allergies
  • Home Allergies
  • Medicine Allergies
  • Acute Allergic Reactions
  • Insect Bite Allergies

Frequently Asked Questions

To determine if your dog has a grain allergy, watch for symptoms like itchy skin, gastrointestinal issues, and chronic ear infections. Confirm the allergy through an elimination diet by removing grains for 8-12 weeks, then reintroducing them to see if symptoms return. Consult your veterinarian for guidance.

Food allergies have no cure, but they can be managed effectively by identifying and avoiding the specific allergens that cause reactions.

Dog food intolerance can result in abnormal stool, often characterized by loose or watery consistency, mucus, increased frequency and urgency of bowel movements, and unusual colors such as yellow or green. If you observe these symptoms in your dog’s poop, it is advisable to consult your veterinarian for proper diagnosis and management.

The beef allergy symptoms in dogs typically include itching, red and inflamed skin, chronic ear infections, and gastrointestinal issues such as vomiting and diarrhea. Additionally, dogs may exhibit excessive licking or chewing of their paws and other body parts and frequent scratching. If you suspect your dog has a beef allergy, it’s important to consult with a veterinarian for proper diagnosis and management.

It typically takes 8 to 12 weeks for dog food allergies to clear once the allergenic ingredients are completely removed from the dog’s diet. During this period, it’s important to follow a strict hypoallergenic diet and avoid other foods or treats that could trigger an allergic reaction. Consistent monitoring and adherence to the recommended diet are crucial for effectively managing and resolving food allergy symptoms.

The Bottom Line

Consulting with a veterinarian is crucial when diagnosing and managing dog food allergies. A professional diagnosis ensures your dog receives the most accurate and effective care. Veterinarians are trained to distinguish between food allergies and other conditions that may cause similar symptoms, such as environmental allergies or food intolerances. They utilize a combination of medical history, physical examinations, and diagnostic tests to pinpoint the exact cause of your dog’s symptoms. This thorough approach helps develop a tailored treatment plan that addresses your pet’s specific needs, avoiding unnecessary dietary restrictions and ensuring balanced nutrition.

Like It? Subscribe & Share!

* indicates required


Canine Bible uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process and product review methodology to learn more about how we fact-check, test products, and keep our content accurate, reliable, and trustworthy.

  1. Pet Coach
Editorial Team at Canine Bible | + posts

Canine Bible authorship represents the unified voice of our entire editorial team and our in-house veterinarians rather than a single author. Each article, blog post, and review published under the Canine Bible name undergoes a rigorous review process, involving all team members to guarantee accuracy and up-to-date in accordance with the latest veterinarian research. This collaborative effort is an integral part of our editorial process and aligns with our four pillars of content creation. This approach ensures our content is backed by expert knowledge and factual information, offering our readers reliable, actionable, and trustworthy content.

Similar Posts