Cell proliferation kinetics of epidermis, hair follicles, and sebaceous glands of cocker spaniels with idiopathic seborrhea.

Cell proliferation kinetic values were established for the epidermis, hair follicle epithelium, and sebaceous glands of 8 Cocker Spaniels with primary idiopathic seborrhea. Values were established by intradermal pulse labeling injections of tritiated thymidine followed by cutaneous biopsy and autoradiography. The epidermal basal cell-labeling index was 4.96 +/- 0.97%, and the epidermal nucleated cell-labeling index was 3.33 +/- 0.71%. Calculated epidermal cell renewal time for the viable layers of the epidermis was 7.85 +/- 1.80 days. The hair follicle infundibulum basal cell-labeling index was 5.48 +/- 2.01%, and the sebaceous gland basal cell-labeling index was 5.94 +/- 4.15%. When compared with previously reported cell kinetic values for Cocker Spaniels and Beagles with healthy skin, these data indicate accelerated cellular proliferation in all 3 cutaneous structures in seborrheic Cocker Spaniels.