Ringworm in Young Cattle
This fungal skin disease often appears in weaned calves and yearlings during winter, but generally disappears without treatment by spring. Young animals are most susceptible because they have no immunity.
“Ringworm can spread from species to species, including humans,” says Matt Miesner, clinical assistant professor in the Kansas State University College of Veterinary Medicine. When handling cattle with ringworm, avoid contact with these skin lesions.
The fungal spores may spread by direct contact with another animal or by coming into contact with something an infected animal has rubbed on — or equipment used on an infected animal and then a susceptible one. The fungus becomes established on the skin of the susceptible animal and infiltrates the hair follicles. The lesions develop about three weeks after the animal is exposed.
“One way to help keep ringworm from spreading is to disinfect tools or equipment used on more than one animal,” explains Miesner.
The spores are hardy and may survive for several years in dry scabs and scales shed by affected cattle that are rubbing and itching. Calves or yearlings may develop ringworm in the fall and winter even if no animals in the herd showed signs of ringworm during summer. The fungus thrives in dark, moist conditions, and is thus a common winter problem when days are short and cattle have long hair.
In early stages the affected areas are small, with slightly raised skin and rough hair. After several weeks the hair falls out, leaving thickened patches of scaly gray lesions — often on the face and neck and around the eyes. These areas are itchy and the animal rubs them.
Adult cattle have generally encountered the fungus and have some resistance, so they don’t get ringworm. However, if spores are present on their bodies, they may pass the disease to young animals.
“The disease generally runs a course within a few weeks or months and disappears without treatment. Sunlight and adequate vitamin A in the diet may help animals get rid of the lesions quicker,” says Miesner.
“Treating ringworm can be frustrating. The lesion will eventually resolve anyway. The main things that help are sunlight and dry conditions. The biggest thing is to try to keep it from spreading,” says Miesner.
There are a number of anti-fungal drugs that can be effective, but some topical treatments such as iodine or chlorine bleach only work well if you first wash and remove the scabby lesions with soap, water and a stiff brush before applying the medication.
Editor’s Note: Heather Smith Thomas is a cattlewoman and freelance writer from Salmon, Idaho.
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