Canine Allergy Skin Test vs Blood Test

When it comes to detecting inhalant allergies, there is an allergy skin test and blood tests that may be used. Both types of allergy testing can give conclusive results, but they differ in methodology. The tests should pinpoint the allergen(s) and give a response as to what is the most suitable treatment.

Canine Allergy Skin Test

The allergy skin test for canines is technically known as intradermal testing, and it can be performed on small areas of the dog's skin. The skin may be shaved and the vet will inject common allergens that are suspected to create irritation in the pet. The skin may be divided in small squares, so that the vet can identify the allergen.

The pet should respond with an allergic reaction on the portion of the skin that has been injected with the culprit allergen. The allergic reaction should appear within six hours of the testing, otherwise the test will show that the dog is not allergic to the injected substances. The allergic reaction is typically swelling and/or the occurrence of a rash. The injected solutions will contain diluted amounts of allergens.

Blood Allergy Test

The allergy test performed on a blood sample may be performed in two ways:

  • The RAST (radio allergosorbent)
  • ELISA test (enzyme linked immunosorbent assay)

Both tests were first used in humans to detect allergies, and have been adapted for use in pets. These tests are similar in method and will give equally conclusive results. The dog's immune system will produce an antibody, should he be allergic to a substance. The antibody produced is specific for each allergen in part. For instance, the antibody produced if the dog is allergic to pollen is known as the IgE.

Skin Test vs. Blood Test

When it comes to allergy testing, each vet will decide which method is more suitable.

The main disadvantage of the skin testing is that if the injected substances are not the ones that cause allergies in the dog, a new set of tests will have to be performed. There may also be unidentified allergens that are not even suspected, and the tests may not reveal the exact allergen.

The blood tests require only a sample of blood which will be tested for antibodies, and the results will be available in a few hours. However, there may be antibodies that are not identified and the vet may not establish the allergen.

The blood tests may give more results from a simple test, while the skin testing may require repeated injections. The skin test may be used if the vet suspects one of several allergens. The blood tests may be more effective if the vet has no clue about what the allergen may be.

However, neither of the two types of tests guarantees that the allergen will be identified and neither of the tests are effective in identifying food or contact allergies.