Food allergies can significantly impact your pet’s comfort and quality of life. Understanding how food allergies work, recognizing the symptoms, and knowing how they are properly diagnosed can help you and your veterinarian create an effective plan to keep your pet healthy and comfortable.
Just like people, pets can suffer from food allergies. In these cases, your pet’s immune system mistakenly identifies a component of their food as a foreign substance and launches an immune response against it. The most common food allergens in pets include beef, dairy, chicken, and wheat.
How Do I Know If My Pet Has Food Allergies?
Your pet’s medical history plays a crucial role in diagnosing food allergies. In most cases, food allergies primarily affect the skin, leading to itchiness and discomfort. Common signs include recurrent ear infections, skin infections, generalized itching, excessive paw licking, and scooting or anal gland issues. Some pets may also experience gastrointestinal symptoms such as diarrhea.
Food allergies cannot be definitively diagnosed through blood testing alone. While blood tests are available, they are often unreliable and generally not recommended. A true diagnosis is made through a controlled diet trial. For additional information, please review our Allergies handout.
What Is a Diet Trial?
If your veterinarian, Dr. Aparna Modi, suspects a food allergy, she will likely recommend a diet trial. During this process, your pet is fed only a specific prescription diet designed for pets with food sensitivities. These diets fall into two main categories: Hydrolyzed Protein diets and Novel Protein diets.
Hydrolyzed Protein Diet
Hydrolyzed protein diets contain proteins that have been chemically broken down into extremely small components. These protein fragments are so small that your pet’s immune system does not recognize them as allergens, preventing an immune reaction.
Novel Protein Diet
Novel protein diets use protein sources your pet has never been exposed to before, such as venison, duck, or rabbit. These diets are most effective when your pet’s dietary history is well known. By introducing a completely new protein, the immune system is less likely to react.
By feeding only a hydrolyzed or novel protein diet, food-based allergens are removed as a variable. If symptoms persist after completing a diet trial, food allergies are less likely to be the cause of your pet’s condition.
Why Can’t I Use Over-the-Counter Foods or Treats?
Switching from one over-the-counter food to another with a different protein source may seem helpful, but it does not qualify as a true diet trial. Prescription hydrolyzed and novel protein diets are manufactured under strict conditions to prevent cross-contamination. All equipment is thoroughly cleaned between batches to ensure no trace amounts of other proteins are present.
Over-the-counter diets do not follow these same protocols. Manufacturing equipment is often shared between multiple protein sources, increasing the risk of cross-contamination. Additionally, chicken fat is commonly used as a flavoring agent in many commercial foods, meaning even beef, lamb, or salmon-based diets may still contain chicken products.
Even small exposures to an allergen can trigger an immune response. For pets with food allergies, this can lead to continued symptoms despite dietary changes.
A proper diet trial requires feeding only the prescribed hydrolyzed or novel protein diet for a minimum of eight weeks. All non-prescription treats, table scraps, and flavored medications must be avoided during this time. By strictly controlling your pet’s diet, your veterinarian can more accurately determine whether food allergies are contributing to your pet’s symptoms and recommend the most appropriate long-term care plan.