Keratinopathogenic mould fungi and dermatophytes in healthy and diseased hooves of horses

Specimens of hoof horn from 187 horses were examined for a possible relatio nship between clinically affected hooves and the occurrence of pathogenic f ungi. Specimens were taken from the coronary band and from the stratum exte rnum and medium of the coronary horn and transferred on to Sabouraud dextro se agar, with and without cycloheximide, and incubated at 28 degreesC. Derm atophytes and mould fungi were identified by their macroscopic and microsco pic characteristics. The 732 isolates could be assigned to 26 species of mo ulds, two different species of the dermatophyte Microsporum and three diffe rent species of the dermatophyte Trichophyton. Depending on their pathogeni c potential they were assigned to three groups: (i) fungi known to be kerat inopathogenic (Acremonium blochii, Alternaria alternata, Alternaria chlamyd ospora, Geotrichum candidum, Microsporum ferrugineum, Microsporum gypseum, Scopulariopsis brevicaulis, Trichophyton species, Trichophyton mentagrophyt es, Trichophyton schonleinii, 57 isolates), (ii) a group of uncertain patho genicity (223 isolates), and (iii) a group of non-pathogenic species (452 i solates). Eighty per cent of the samples from horses with hoof horn lesions and 66.7 per cent of the samples from horses with slightly affected hoof h orn contained fungi of the keratinopathogenic group, whereas only 8-9 per c ent of the samples from horses with healthy hoof horn contained fungi of th is group. There were no significant correlations between the clinical data and the age, sex or breed of the horses or their bedding and hygiene. Twelv e species of fungi were isolated from the air in the horses' stables, but n one of them belonged to the keratinopathogenic group.