In the skin samples of healthy dogs, CB1 and CB2 receptors immunoreactivity was detected in various types of cells in the epidermis and in cells in the dermis, including perivascular cells with mast cell morphology, fibroblasts, and endothelial cells; in the skin samples of dogs with atopic dermatitis, CB1 and CB2 immunoreactivity was stronger than it was in skin samples of healthy dogs [49]. This evidence concerns the gene CNR1 and atopic eczema.