We report our findings in three dogs diagnosed with canine atopic dermatitis(CAD), who had high specific IgE levels for the house dust mite(HDM). The intradermal skin test was administered in all three cases using the domestic HDM antigen (10,000 JAU/ml; prepared by 10-fold dilution of the 100,000 JAU/ml stock) (for use in humans, Torii yakuhin Corporation, Tokyo, Japan) and the overseas HDM antigen (12,000 PNU/ml) (for use in dogs, Greer Corporation, Lenoir, NC, USA). The effects of the antigens were compared using an objective index (pomphus diameter) . The results revealed no statistical difference (p > 0.05), indicating equal antigenicity between the two HDM antigens in the intradermal skin test in dogs with CAD.