How does a Veterinary Dermatologist test dogs for allergies?

Allergy testing for dogs can be done by intradermal allergy test (intradermal skin test) or by blood test. The intradermal test is considered the most reliable. For the intradermal test, dogs are typically lightly sedated (not under general anesthesia), a patch of hair is clipped on the side of the chest and multiple allergens are injected into the skin. Reactions are measured and recorded.