Histology of ferret skin: preweaning to adulthood.

Ferrets are important companion animals that incur a multitude of cutaneous diseases requiring diagnostic dermatohistopathology. This study provides a description of the histology of normal ferret skin, emphasizing changes in the interval from preweaning to adulthood, an essential basis for identification of pathological situations. Skin samples obtained post-mortem from 29 topographical sites on 41 ferrets, revealed in the haired, general body surface skin an epidermis consisting of strata basale, spinosum, granulosum, and corneum and a dermis consisting of strata papillare and reticulare. Adult skin contained compound hair follicles composed of one primary hair and a collection of secondary hairs with a primary to secondary ratio of 1/5-1/15. All hairs emerged through the same follicle outlet of the skin surface. There was associated with each primary follicle, an arrector pili muscle, a multilobular sebaceous gland, and a coiled tubular sweat gland, but secondary hairs lacked these features. Compound follicles, grouped mainly as triads across the body surface, were already fully formed in the youngest group studied (3 to 6 weeks). The secondary hairs all developed from one specific region of the primary follicles and smaller ones were formed with increasing age. The differences found in specialized body regions are described. Demodex sp. mites were found in follicles and sebaceous glands in nine of 25 individuals in the perianal, vulvar, preputial, facial, and caudal abdominal skin.