Experimental dermatophytosis in calves caused by Trichophyton verrucosum culture

Summary Microconidia suspension of Trichophyton verrucosum virulent culture isolated originally from the mycotic lesions of cattle was inoculated epicutaneously to calves in various doses. Four application methods were selected, namely, onto the sheared and gently scarified skin, onto the sheared and non-scarified skin, onto the non-sheared and gently scarified skin, and onto the non-sheared and non-scarified skin. The inoculated area was 10 × 10 cm for all cases mentioned. When the application was performed onto the sheared and scarified skin, at least 18 000 microconidia of T. verrucosum per one animal had to be used to induce the mycotic disease in 100% of animals. This value was 10 times higher when the application was performed onto the non-sheared and scarified skin, 100 times higher in the case of the sheared and non-scarified skin and 1 000 times higher in the case of the non-sheared and non-scarified skin. The minimum infectious dose still capable of inducing dermatophytosis was 180 microconidia per 100 cm2 of the scarified skin, 18 000 microconidia per 100 cm2 of the sheared and non-scarified skin, and 180 000 microconidia per 100 cm2 of the non-sheared and non-scarified skin.