Ringworm is a highly contagious skin disease caused by a spore-bearing fungus. The spores germinate, attacking the surface of the skin and the hair follicles. Ringworm typically attacks the legs and calves of adult cattle, and appears around the eyes, ears and backs of young calves. The result is a greyish-white skin tone spattered with circular, raised lesions. Although unpleasant to look at, ringworm causes little permanent damage and is usually quite treatable.
Imaverol is a synthetic anti-fungal drug that is applied as a topical spray. After any crusting is removed from the cattle's skin with a brush, the spray should be applied 3 to 4 times a day every 3 days.
Griseofulvin is an anti-fungal drug that can be given orally (in the cattle's feed) to treat ringworm. However, griseofulvin is no longer approved for use in food-producing animals.
A tincture of iodine is a very common treatment for ringworm in cattle. Typically, a 2 per cent iodine solution is used, as this is less irritating to the skin.
Lime Sulfur Solution
According to "Rebhun's Diseases of Dairy Cattle" by Thomas J. Divers, Simon Francis Peek and William C. Rebhun, a 2 to 5 per cent lime sulphur spray is an effective treatment for ringworm in cattle.
Topical Pastes and Creams
"Rehbun's Diseases of Dairy Cattle" also recommends a 3 to 5 per cent thiabendazole paste, a miconazole cream or a clotrimazole cream applied once or twice daily as viable treatments for limited lesions on cattle.