Dermatophilosis

Abstract

Dermatophilosis is an infectious, contagious disease of the skin of cattle and other animals caused by the aerobic actinomycete, Dermatophilus congolensis. Dermatophilosis is typified by an exudative dermatitis with suppuration, superficial epidermal necrosis, acanthosis and the build-up of scabs along entrapped hairs over the infected skin surface. The causative organism, an obligate parasite, has been cultured only from lesion materials; it has a multimorphic life cycle including a motile (flagellate) zoospore form, a branching filamentous form and a multiplanar septate form. The infection is transmitted by direct contact or by insect, arachnid and inanimate vectors. Moisture on the skin enhances transmissibility and causes exacerbation of existing lesions. The disease is most prominent in temperate to tropical climates during the rainy season. Diagnosis depends on microscopic demonstration of typical multiplanar septate forms in Giemsa-stained smears of exudate or cultural isolation by special techniques described. Serologic and fluorescent antibody applications are also described. The infection may be treated successfully by a number of bacteriocidal solutions including copper sulfate and by antibiotic injections including dihydrostreptomycin. Control of flies and other vectors and keeping animals dry are important considerations in controlling dermatophilosis in cattle. Some evidence exists indicating that an actively acquired immunity may be induced through experimental vaccination. The disease is economically important through reduced productivity of affected cattle and residual hide damage. Dermatophilosis is transmissible to man and is considered to be a zoonotic disease.