Histopathology of dermatophytosis in cattle calves

Dermatophytosis, commonly known as ringworm is of considerable importance in domestic animals due to its wide host range and zoonotic importance. In the present study, pathological changes in ringworm affected cattle calves along with demonstration of fungal hyphae by special stain have been worked out. Cattle showing suspected lesions were examined for dermatophytosis. Skin scrapings were taken from animals showing suspected lesions and were examined by direct microscopy and cultural examination. Direct microscopic examination of the skin scrapings revealed fungal spores and hyphae indicative of Trichophyton spp. From the confirmed cases of dermatophytosis, skin biopsies were collected, processed and examined histopathologically using a special stain. The lesions were mainly confined on the head, around the eyes, neck, dewlap and forelegs and were grayish-white, crusted, circular, raised, thick and circumscribed. There was hypertrophy and acanthosis of epidermis, destruction of hair follicles and abscesses in many hair follicles associated with leucocytes infiltration in the dermis. The GMS stained tissue sections revealed black coloured hyphae of the fungi in the hair follicles.