However, because ringworm is a transmissable infectious disease, animals with lesions are barred from exhibitions or shows by regulations of the State Board of Animal Health. Infection of the skin and hair of cattle is most frequently due to Trichophyton verrucosum, a spore forming fungi. Spores are shed from the lesion by broken hairs or scabs from the lesion. Transmission Direct contact with infected animals, particularly with cattle confined to a barn, is a common method of spreading the fungi. Show calves are frequently infected from spore contaminated equipment that has not been properly cleaned.
Spores germinate and attack the shafts of the hair and the surface layers of the skin.
Exudate oozes from the damaged skin and mixes with debris from skin and hair, thereby forming a crusty scab. The scab is grey-white and noticeably higher than the surrounding skin. Infection spreads from the center outwards and results in the circular lesion 1 to 1.5 inches in diameter. Adjacent lesions may overlap and create larger infected areas. Lesions are most frequent on the head and neck, but they may be found over the entire body in severe cases.