Ringworm in Cattle

Last updated: November 2026

Ringworm in cattle is a fungal skin infection, mostly caused by Trichophyton verrucosum, that shows up as round, gray, crusty patches and spreads easily through direct contact and contaminated barns and equipment.^1,2,3 It is most common in young cattle during winter housing.^1,2 It can pass to people, and its spores can survive in buildings for years, so cleaning pens, chutes and tools is as important as caring for the animals.^3,5

What causes ringworm in cattle

Despite the name, no worm is involved. Ringworm (dermatophytosis) is caused by fungi that live on the outer layer of skin and in hair.^1,2 In cattle, Trichophyton verrucosum causes the large majority of cases.^2,6 The fungus produces spores that stick to hair, skin flakes and surfaces, and these spores carry the infection from animal to animal.^1,3

Signs to look for

• Round, well-defined patches of hair loss, often 1 to 5 cm across, that can merge into larger areas.^1,3
• Thick, gray-white, crusty or ash-like scales on the patches.^2,3
• Most often on the head and neck, especially around the eyes and ears; in older animals also on the body and legs.^1,2
• Usually little itching.² Animals tend to rub against posts, rails and feeders, which spreads spores.

Signs usually appear one to four weeks after exposure.¹ In many animals the patches fade within a few months, but severe cases affect welfare, hide value and sale or show eligibility.^1,3

How it spreads

Risk rises when young stock are housed closely in winter, with less sunlight, higher humidity and more contact between animals.^1,2,3

Risk to people

Cattle ringworm is a zoonosis: it can infect farmers, veterinarians, children who show calves and anyone who handles infected animals.^5,6 In people it typically causes red, ring-shaped, sometimes inflamed patches on the hands, arms, neck or face.¹ Wear gloves when handling affected cattle, wash hands and arms afterward, keep work clothes separate and see a doctor about any suspicious skin patches.¹

How long spores survive

Ringworm spores are hardy. Veterinary sources report that they can persist on wood, metal and bedding in buildings for years, often cited as up to four years.^3,5,8 That is why new groups of animals can become infected in a pen that held cases seasons earlier, and why thorough cleaning between groups pays off.³

Cleaning and disinfecting the barn

The goal is to remove the material that holds spores, then treat the clean surfaces.⁴ Follow these general steps, and the label of any product you use.

1. Remove animals and bedding. Take out all bedding, manure and loose feed.
2. Dry clean. Scrape and brush walls, rails, feed barriers and posts to remove hair, scale and dust.^1,4
3. Wash. Wash surfaces with detergent and water, ideally a pressure washer, until no visible soil remains. Disinfectants work poorly on dirty surfaces.^1,4
4. Disinfect. Apply a disinfectant suited to fungal spores on farm surfaces, covering every surface fully.^1,4
5. Respect the contact time. Leave the product wet on the surface for the full time stated on its label.
6. Dry. Let the building dry fully before restocking. Spores and moisture go together.

Treat equipment the same way: brushes, halters, clippers, show gear, chutes and trailers.^1,3 Wooden surfaces are porous and harder to clean, so they need extra attention. Our guides to ringworm cleaning in animal facilities, disinfectant types compared and the terminal cleandown protocol go into more detail, and the dairy cattle environment page covers wider herd hygiene.

When to call a veterinarian

• When ringworm appears in a herd for the first time, to confirm it is ringworm and not another skin condition.²
• When many animals are affected or lesions are severe.
• Before shows or sales, where rules on visible lesions may apply.³
• To discuss treatment options and herd vaccination.

Vaccination

In some countries, including much of Europe, a live vaccine against Trichophyton verrucosum is available and is used to protect young stock and reduce cases across a herd.^1,2,7 Availability differs by country, so ask your veterinarian what is licensed where you farm.