Both intradermal skin testing and serum (blood) allergy testing are offered. Although serum allergy testing can give meaningful results, intradermal skin testing is considered to be more accurate and is the preferred method of allergy testing in dogs. However, several medications can interfere with intradermal skin testing and therefore, the patient should not have any antihistamines (amitriptyline, hydroxyzine or atarax, benadryl, chlorpheniramine) or tranquilizers (acepromazine) for at least 7 days prior to intradermal allergy testing. The effects of corticosteroids (prednisolone) on allergy testing are somewhat controversial, but it is generally accepted that steroids should be withdrawn (if possible) for 2 weeks prior to intradermal skin testing. If the patient’s level of itch makes it impossible to go 2 weeks without corticosteroids, please contact Dr. Hansen’s staff for specific instructions.