Skin biopsies were taken from female dogs, the primary hair follicles isolated and the dermal papilla dissected. After incubation in supplemented Amniomax complete C100 medium in 24-well culture plates, the dermal papilla cells (DPC) grew to confluence within 3 weeks. Thereafter, they were subcultivated every 7 days. Dermal fibroblast (DFB) cultures were established by explant culture of interfollicular dermis in serum-free medium, where they reached confluence in 10 days. They were subcultivated every 5 days. For immunohistochemistry, cells were grown on cover slips for 24 h, fixed and stained with antibodies against collagen IV and laminin. DPC showed an aggregative growth pattern and formation of pseudopapillae. Intensive staining for collagen IV and laminin could be observed until the sixth passage. DFB grew as branching, parallel lines and showed only weak staining for collagen IV and laminin.

Skin biopsies from seven different body sites were obtained from 21 dogs of different breeds (short, normal, long hair), which were presented for euthanasia. Commercially available polyclonal antibodies were used for the immunohistochemical detection of androgen and oestrogen receptors. Both receptors showed a similar distribution in canine skin, with specific intranuclear staining. In the epidermis, the percentage of androgen receptor (AR)-positive cells, but not that of oestrogen receptor (ER)-positive cells, was significantly higher in samples from the thorax and the flank. In the dermal papilla, the percentage of ER-positive (but not AR-positive) cells was significantly lower in biopsies from the flank. No significant difference was found for both receptors between the locations in the outer root sheath, among the three different hair types, between sex and between intact and castrated dogs.