Fungal and bacterial isolation from racehorses with infectious dermatosis

Abstract

To clarify the microbiological causes of dermatosis in racehorses, clinical samples were collected from the skin lesions of dermatosis in racehorses and cultured. Trichophyton equinum was isolated purely from 26 of 87 racehorses (29.9%) and Microsporum equinum from 3 of 87 (3.4%). Staphylococcus hyicus was isolated predominantly from 22 racehorses (25.3%) and Staphylococcus aureus from 21 (24.1%) in cases except dermatophytosis. S. hyicus was most frequently isolated from the skin regions in contact with a harness in large amounts of sweat, suggesting secondary infection to eczema. S. aureus was isolated predominantly from most of the skin lesions of dermatosis with scabs in the white areas of the fetlocks and pasterns. Thus, S. aureus was considered to play an important role in this dermatosis. The present study suggests that two kinds of dermatophytes and two kinds of Staphylococcus are important as causal pathogens of infectious dermatosis in racehorses.