DERMATOTOXICITY OF AGRICULTURAL CHEMICALS IN THE DORSAL SKIN OF HAIRLESS DOGS

Dermatotoxicity of agricultural chemicals (ACs) with or without ultrav iolet (UV) irradiation was histologically examined using hairless desc endants of Mexican hairless dogs. ACs examined were pentachlorophenol sodium salt, 2,4-dichlorophenoxyacetic acid (DCPAA), Maneb, and Zineb. One day after cessation of the 7-day AC treatment, the skin treated w ith DCPPA and Maneb indicated only slight histological changes. The UV +AC-treated sites had as much pigmentation as the control sites. Fourt een days after cessation of treatment, dogs treated with Maneb showed marked reactions such as epidermal degeneration, vasodilation, and int radermal infiltration of inflammatory cells. These histological change s were more severe in the UV+AC-treated sites. Zineb induced comedones with well-developed pilosebaceous glands. These results suggest that hairless dogs may be useful laboratory animals for the investigation o f dermatotoxicity of ACs in conjunction with UV irradiation.