Allergy Tests for Dogs

Allergy tests for dogs may be conducted by blood antigen testing or by intradermal skin testing. An elimination diet may also be used to test for food allergies. After allergy testing, the dog can receive hyposensitization injections to reduce or eliminate allergies. All types of allergy testing have both benefits and drawbacks.

  1. RAST Test

    • A RAST test is an allergy test that requires blood to be drawn and exposed to test allergens. Antibodies will attach to a substance if the dog is allergic to it. A radioactive substance is used to measure the test results. This test can be used to identify environmental and food allergies.

    ELISA Test

    • The ELISA, or "enzyme-linked immunosorbent assay" test, is the second type of blood test that can determine if a dog has allergies. The ELISA test also measures antibodies when a dog's blood is exposed to specific allergens. Unlike the RAST test, a radioactive substance is not required. ELISA tests tend to be less costly than RAST testing and may also be more effective in determining what causes a dog's allergies.

    Intradermal Skin Testing

    • Intradermal skin testing is the most effective method of testing for atopy, or "inhalant dermatitis," an allergic skin reaction to environment allergens like pollen or animal dander. The dog must be sedated and a large area on his side must be shaved for this testing method. Small amounts of several allergens are injected into this shaved skin. After several hours, the dog is examined to determine which allergens have caused a significant enough reaction in the skin to be likely causes of the dog's allergy symptoms.

    Elimination Diet

    • An elimination diet may be used to test for food allergies. This diet involves eliminating all proteins and carbohydrates to which the dog has been previously exposed and replacing them with a single protein, single carbohydrate diet entirely new to the dog. After a diet has been identified that doesn't cause allergic symptoms and this diet has been fed exclusively for some time, the owner can reintroduce one ingredient of the dog's former diet at a time. When allergy symptoms return, an allergen has been identified. Common food allergens include corn, wheat, soy and chicken. These ingredients are found in many low-quality pet foods. Over time, dogs develop allergies due to constant exposure to a food, particularly if it is difficult to digest.

    Warnings

    • Allergy testing is not infallible. Dogs may test negative for all the allergens to which they are exposed during testing, yet still suffer from obvious allergy symptoms. In this case, it may be necessary to treat allergies symptomatically and attempt to limit exposure. Allergy tests don't provide a cure. After allergy testing has been performed, hyposensitization injections can be formulated for the individual dog's specific sensitivities. These injections do not always succeed in eliminating or reducing allergy symptoms, even when used exactly as directed.