Pathological Leisions in Bovine Skin Naturally Infected With Dermatophilus congolensis in Zaria, Nigeria

Abstract

Dermatophilosis is a contagious zoonotic skin disease caused by a Gram-positive actinomycete, Dermatophilus congalensis. The effect of the disease on the production and sales of hides are considerable. Lack of concrete establishment of the etiologic agent and producing the natural disease experimentally in laboratory animals or ideal susceptible hosts have limited the control of Dermatophilus infection. Understanding the pathogenesis of the disease by pathological studies would provide an in-sight into the ways of controlling the disease. The objective of this work is to study the pathological lesions of dermatophilosis in naturally infected bovine skin. One thousand, one hundred and twenty (1,120) cattle slaughtered in Zaria abattoir from June to October, 2007 were examined for skin lesions suspected to be dermatophilosis. Skin samples were obtained from 150 (13.4%) animals with skin lesions for bacteriology and histopathnlogy. Those for bacteriology were collected aseptically in sterile containers and stored at 4°C while those for histopathology were fixed in 10% neutral buffered formalin. Out of one hundred and fifty samples processed for bacteriology, 65 (5.8%) were positive for D. cungolensis. Histopathology of infected bovine skin revealed hyperplasia of the epidermis, parakeratosis, necrosis. cellular infiltration of the hair follicles and papillary dermis. Diffuse cellular infiltration of the reticular demis and folliculitis were also observed in some sections. Hyphae of D. congolensis were detected in the superficial hyperplastic and hyperkeratotic epidermis. It was concluded that the pathological lesions observed were mainly proliferative and inflammatory in the epidermis.