Allergy Testing in Dogs

Allergies can be described as an abnormal reaction of the immune system to something normal in the environment, such as pollen or dust mites. These allergens make their way through the skin barrier and cause skin inflammation and itch.

Allergy testing can be an effective way to determine what your dog is allergic to. Veterinary dermatologists may use intradermal skin testing or blood testing to identify the offending allergens. Testing for food allergens is not accurate and over the counter food allergy tests are not reliable. If a food allergy is suspected, a diet trial is recommended.

Once an intradermal skin test or blood test is performed and allergens are identified, allergen specific immunotherapy (allergy shots) can be formulated for each patient. Allergen specific immunotherapy presents small doses of allergens to condition the immune system. At the beginning of immunotherapy, very small doses of the allergen are introduced and gradually increased until a maintenance dose is reached. Immunotherapy can be administered by subcutaneous injection (Allergen Specific Immunotherapy – ASIT) or sublingually (Sublingual Immunotherapy – SLIT). Sublingual means to deposit the liquid under the tongue to be absorbed through the gums/mucosa, not swallowed, so it is not given with food. ASIT injections are often given weekly, whereas SLIT is often given daily. Owners can be taught both means of administration.

Immunotherapy is a long term maintenance tool for allergies that can improve management success. Because it takes time to test, develop the specific immunotherapy and work up to the maintenance dose, other management strategies will be needed at least in the short term to control itch and inflammation. Although immunotherapy can be a large time and economic investment, it can improve the overall success of allergy management and reduce the amount of other required medications/treatments. It is a bit of a gamble as approximately ¼ of dogs will not respond well to immunotherapy. However, half of dogs will respond very well and the remaining ¼ show good response.