1. Blood Testing
Blood testing is most widely used to detect allergies in pets or humans. Blood tests to detect allergies may include:
- The radioallergosorbent test (RAST)
- The enzyme linked immunosorbent assay test (ELISA)
These tests will be performed on a blood sample and the tests will reveal the presence of a certain antibody in the dog's blood. When the dog is allergic to a substance, the immune system produces an antibody that is specific for each substance in part. For example, if pollen is the culprit allergen, the dog will produce an IgE antibody, which is specific for pollen allergies.
Blood testing will not give conclusive results in food or contact allergies.
2. Intradermal Testing
Intradermal testing can be applied to dogs that are suspected to have an inhalant allergy. The intradermal testing is not suitable for food testing.
The intradermal testing will be performed by injecting a few common allergens under the dog's skin. The allergens will be diluted and the vet may mark the dog's skin, so that he knows which allergen was injected where. Within five hours of the injections, the dog should display an allergic reaction in the spot injected with the culprit allergen. If no allergic reaction is present, the test may be repeated using a different set of allergens until finding the right one.
3. Trials or Elimination Tests
If you suspect a few possible allergens in your dog's environment, you may test him.
Eliminating the suspected allergen from the dog's environment will reduce your pet's symptoms. However, you must know that the allergic reactions may still be present for up to two weeks after the dog is no longer exposed to a certain allergen.
This type of testing is not suitable to detect pollen allergies, as the dog is constantly in contact with these during the spring and autumn. However, you may realize your dog is allergic to pollens if he only displays allergic reactions during the pollen season.
Most commonly, the elimination tests are successful in detecting contact allergies and food allergies.
With contact allergies, you will eliminate one possible allergen from the dog's environment (i.e., plastic or wool) and monitor him.
Food testing can be more complicated and lengthy. The dog will start the testing by getting a diet that contains only one source of proteins and one of fibers, and these should not be present in the dog's usual diet. The dog should receive this diet for two to four weeks, and if no allergic reaction occurs, a new ingredient will be introduced. Every two weeks a new ingredient will be added and the dog will be constantly monitored. If the dog starts displaying an allergic reaction, the allergen is the latest ingredient introduced.