Diagnosing and Treating Food Allergies in Dogs and Cats

Did you know chicken and beef are the most allergenic foods for dogs and cats? As a small animal veterinarian, I am often the second opinion for food allergies in pets. Some vets misdiagnose or overlook issues because the symptoms often vary greatly and overlap with other common ailments. And often, pet parents are surprised to learn their dog or cat is allergic to one of the two most popular proteins found in pet foods. I spend a lot of time educating clients about spotting and treating potentially dangerous food allergies.

Food allergies in pets can be a confusing topic due to the overwhelming amount of information available on the internet. While some information is truthful and helpful for pet parents, many times, it is misguided and sends you down the wrong path for treatment. So let’s discuss food allergies in pets, from diagnosis to treatment options, and clear up any misconceptions.

What is a pet food allergy?

There are two different types of food allergies in pets – hypersensitivity reactions and food intolerances. A hypersensitivity reaction involves the body’s immune system, which produces a reaction when exposed to an allergen over time. Food intolerance can occur with the first exposure to a particular food and is commonly seen in young animals.

Both types of allergy, hypersensitivity or intolerance, can present in the same way and be difficult to tell apart without veterinary guidance. Many pet parents find it hard to believe that pets with food allergies are often allergic to the protein from animal- or plant-based ingredients in their diet. The immune system misidentifies the protein molecules as a foreign threat to the body.

What clinical signs indicate food allergies in pets?

Symptoms can vary and can present identically to environmental allergies. The most common clinical signs I see is non-seasonal itching, which may involve the whole body or just the perianal area, ears and feet. Oftentimes, food allergy patients come in to be evaluated for chronic or recurrent ear and skin infections. Perianal inflammation and itchiness is a common sign, as well. Some food allergies in pets present with vomiting, diarrhea, or gassiness, but these symptoms are less common. Many times, puppies who are extremely itchy, in fact, have food allergies.

Food allergies can start at any age. Food allergies are at the top on my list for possible diagnoses when dogs younger than 1 year of age come in with chronic itching and skin infections.

What are the most common food allergies in pets?

Chicken, beef, and eggs are the most common food allergies in pets. Sometimes, we see soy and gluten allergies, as well.

How do I test my pet for a food allergy?

Performing a “food trial” with your pet is the only reliable way to diagnose food allergy. There are two types of diets that veterinarians use in food trials – a novel protein diet and a hydrolyzed protein diet. A novel protein source is a completely new protein that your pet has never eaten, eliminating the chances of the body’s immune system recognizing the protein. These diets contain a single source of carbohydrate in addition to the new protein. Common types of hypoallergenic diet are venison, duck, salmon, and kangaroo. Hydrolyzed protein diets are made when intact animal proteins are broken down into tiny molecules so the immune system does not recognize them as allergens.

Food trials last for a minimum of 8-to-10 weeks with absolutely no other foods – not even treats, meat-flavored medications, or preventatives. This part of the test is often challenging for my clients. It is a waste to invest in the new food if you are going to give your pet treats during the trial. You cannot determine if clinical signs are improving if your give your pet other foods during the trial. After the 8-to-10 week trial, we confirm the food allergy with a challenge. You add single source ingredients (chicken, wheat, dairy) one at a time to determine which foods to avoid.

What kind of food should I use if my pet has a food allergy?

Always work with your veterinarian to choose a proper diet for your pet. Again, veterinarians prescribe novel protein and hydrolyzed diets for pets with food allergies. You can only purchase hydrolyzed protein diets with a prescription through your veterinarian. NOTE: I always recommend a prescription diet from your veterinarian when diagnosing a food allergy.

After performing a trial and introducing different limited ingredients to test for specific food allergies, consider placing your pet on a novel protein diet. In recent years, there has been a shift in the way we feed our pets. People are moving away from kibble-based, highly processed diets and toward whole food nutrition. I recommend Side By Side Harvest Free Dried Recipes for many of my patients with food allergies. This diet encompasses whole food nutrition, no artificial additives or preservatives, and novel proteins.

Side by Side Pet Food also incorporates traditional Eastern Food Therapy to help aid in your pet’s individual ailments. Eastern Food Therapy looks at the body as a whole to observe and comprehend your pet and their health. At its core, the therapy seeks to recognize internal imbalances, so we can work to rebalance the body and mind. These principals guide us to utilize the inherent properties of whole food ingredients as tools to help our pets heal and prevent disease.

Additionally, if you would like to make food for your pet, always speak with your veterinarian regarding proper supplementation. Nutritionally balanced, home cooked diets provide excellent benefits for your pets.

Final Thoughts on Food Allergies in Pets

I hope this Q&A helps clarify some misconceptions about food allergies in pets. If you suspect your pet has a food allergy, speak with your veterinarian about a proper food trial.

Placing your pet on a 6-to-8-week hypoallergenic diet is not going to set you back or harm your pet in any way. If your veterinarian suspects a food allergy, a food trial is extremely valuable. You have nothing to lose.

Keeping your pets safe and healthy is always my top priority. Helping you avoid unnecessary trips to your veterinarian is a close second! But if you have any questions or concerns, always visit or call your veterinarian. They are your best resource for the overall health and well-being of your pets.