Sequence of Histologic Changes in Skin of Dogs in Relation to Dietary Fat

Abstract

Periodic histologic examinations of the skin were made on 8 young puppies, 4 of which were developing deficiency symptoms due to lack of dietary fat, and on 4 adult dogs, three of which were recovering from the fat-deficient state after the addition of fat to the diet. Rather remarkable was the uniformity of the changing microscopic appearance of the skin both during increasing deficiency states and during recovery. Alterations in the stratum corneum, collagen structure, cellular infiltrate of the dermis, hair follicles, sebaceous glands and sudoriparous glands, all were related to changes in the epidermis, particularly with regard to the number of cell layers. More rapid restoration of the microscopic structure occurred when the dietary fat was high in unsaturated fatty acid content. The findings suggest that dietary fat supplies a factor necessary for the maturation of epithelial, sebaceous and sudoriparous cells which, when absent from the diet, results in distinct abnormality in the skin demonstrable both microscopically and grossly. The process is readily reversible and changes in an orderly fashion when fat is added to the diet.