Ringworm

Dairy cow with ring worm

What to look for

  • Crusty skin lesions that start as small scaly patches and slowly enlarge
  • Most often seen on the head and neck
  • Lesions persist for several months then heal completely
  • In very thin or diseased animals the ringworm scabs may persist longer

Cause - a fungal infection (usually Trichophyton verrucosum)

The fungus is very widespread and produces spores that persist in the environment for years, providing a source of infection for the next generation of animals. Spores can also persist on the hair of cattle that do not develop any signs of disease.

Animals likely to be affected

Most often seen in younger animals. Ringworm may occur at the same time as lice infestation, which thrives under similar circumstances.

Other diseases with similar signs

Ringworm is usually fairly distinctive and a diagnosis can be based on the history of the outbreak and the appearance of the characteristic skin changes. However, it is useful to remember that under some circumstances, ringworm might be confused with mange, dermatophilosis or even early stages of warts.

Confirming the diagnosis

If the diagnosis is in doubt your vet can take a sample of hair and skin and examine it under a microscope to demonstrate the causative fungus.

How it spreads

Animals become infected with fungal spores that are picked up from other animals or from rubbing on fences, trees, buildings and other inanimate objects.

Risks to people

People can be infected with cattle ringworm and so it is important to pay attention to personal hygiene when handling infected animals.

Treatment

Ringworm usually clears up in one to two months without any treatment. If you are particularly concerned because of a planned sale or appearance at a cattle show it is possible to clean up the infected area and apply topical anti-fungal treatments.

Prevention

The extent of an outbreak may be reduced by isolating infected animals.