There are 3 major allergens that affect as much as 50% of all dogs in the U.S. The most common is flea bite allergies with as many as 40% of all dogs developing symptoms. The second most common is atopy with a 15% occurrence rate. Atopic allergens refers to inhaled allergens and includes dust, mold, and pollen. Food allergies are the third most common affecting only 10% of reported cases. There are many conditions that present with symptoms similar to those produced by allergens. These conditions need to be ruled out when testing for allergies. 

What is a food allergy?

Meats, grains, and vegetables are a source of proteins and carbohydrates. They are broken down into small molecules.  On occasion the immune system will misidentify these molecules as harmful foreign invaders. The body’s immunologic response is to protect itself by creating defensive antibodies. The symptoms that manifest are the body’s attempt to fight the invader. Previous exposure to the allergen must have occurred for symptoms to develop. In fact, sometimes an animal will eat the same food for quite some time before developing symptoms.

What causes a food allergy?

There is a genetic predisposition to allergies which can be affected by the environment. However, research shows that there are ingredients that seem to cause allergic reactions more frequently in pets. The most common of these is beef followed by dairy products.

Food allergy symptoms

Symptoms include ear and skin infections, hair loss, gastrointestinal problems, diarrhea, vomiting, and itching.

Ruling out alternatives

• There are many other causes for the manifestation of these symptoms.
• Parasites, viruses, and bacteria cause gastrointestinal issues with overlapping symptoms.
• Intolerance for certain foods is also a possibility. A food intolerance is not the same as a food allergy. It does not involve the immune system. Intolerance is more of a digestive issue. Foods that are either too high or too low in fat, fiber, or a number of other ingredients may not agree with your pet.
• Itchy skin and ear infections may be caused by fleas.
• Other types of allergies must also be ruled out as they produce similar symptoms.

Testing for food allergies

Blood, saliva, and hair products that claim to test for food sensitivities offer no proof that they work. The available tests aren’t accurate and can produce false positives and false negatives. The best current method is basically a trial and error approach called a dietary elimination trial. The idea is to purchase or home cook food that has a limited amount of ingredients that have never been fed to your pet before or are either hydrolyzed (broken down into very small pieces) or purified. This new food is fed to your pet for a period of at least a month. Your pet cannot eat anything else during this trail period. If your pet’s symptoms improve, you return your pet to his old diet to see if the symptoms worsen. If they do, your pet is likely allergic to one of the ingredients in his old food. To figure out the culprit, you test one ingredient at a time until the allergy symptoms are triggered.

Treatments

The only long term treatment is eliminating the allergy producing ingredient from your pet’s diet. Treating the symptoms produces short term relief only. Talk with your vet to determine the cause of your pet’s allergy and possible relief options.