Occurrence of dermatophytosis among sheep and goats in Zaria, Nigeria

Abstract

Dermatophytes are a group of related fungi in the genera Tricophyton, Microsporum and Epidermophyton. Infection with any member of these genera results in dermatophytosis, an economically important skin disease of man and animals. The aim of this work was to determine the occurrence of dermatophytosis among sheep and goats in Zaria. Ninety-four goats and 63 sheep skin scrapings were aseptically collected. Each specimen was divided into two parts for direct microscopy and culture respectively. The portion for direct microscopic examination was cleared in 10% potassium hydroxide and examined microscopically. The presence of hyaline septate hyphae in skin scales or spores inside or outside the hair shafts was presumptively considered positive for dermatophytes. The part for culture was inoculated onto Sabouraud’s dextrose agar incorporated with cycloheximide and chloramphenicol and incubated for 2 to 3 weeks. The isolates were stained in lactophenol cotton blue and identified microscopically based on the size, shape and attachment of their macoconidia and microconidia. Twenty-four (25.5%) and 15 (23.8%) of goat and sheep samples respectively were positive for dermatophytes by direct microscopy. Trichophyton mentagrophytes and T. verrucosum were the two dermatophytes isolated from both sheep and goats. The isolation rates were 22.3% (21/94) and 20.0% (13/63) in goats and sheep respectively. Trichophyton mentagrophytes was more frequently (66.7%) isolated than T. verrucosum (33.3%) from goats. Similarly, T. mentagrophytes was more frequently (69.2%) isolated than T. verrucosum (30.8%) from sheep. Dermatophytosis is a health problem among sheep and goats in Zaria with T. mentagrophytes being more commonly isolated than T. verrucosum in both species of animals. In view of the high zoonotic potential of the disease, we recommend the use of protective equipment when handling infected animals.