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.

Hereford heifer calves were experimentally infested with Psoroptes ovis. Histologic examination of skin specimens was conducted at weekly intervals before and after treatment with ivermectin on postinfestation week 7. Electron microscopy revealed numerous degranulating mast cells in the skin of infested but not in control calves. Many active, as well as degenerate, neutrophils were in the scab on infested calves. Microscopic epidermal ulcers developed on infested calves when live mites were present but not after treatment. Numbers of dermal neutrophils and plasma cells decreased and numbers of circulating neutrophils increased 1 week after treatment. Numbers of dermal eosinophils and mast cells in calves with eosinophilia increased for several weeks after treatment. Statistical analysis indicated significant correlations (P less than 0.05) among numbers of dermal inflammatory cells, hemogram values, and changes in dermal thickness. Seemingly, mite-induced epidermal damage was the key pathogenic event in psoroptic scabies in calves. Mast cell degranulation contributed to the pathogenesis of the dermatitis, and neutropenia was caused by sustained, poorly compensated efflux of neutrophils into the scab through mite-induced breaks in the epidermis.

Hematologic values were determined in blood samples obtained from 203 normal, healthy Jindo dogs of both sexes that ranged in age from 3 months to 10 years. Age-related differences were detected for the total erythrocyte count, hemoglobin content, PCV and the number of eosinophils. The persistent eosinophilia appears to be due to the dirofilariasis and flea-allergy dermatitis