Ringworm in horses

Horses can be carriers for a long time without ringworm breaking out. The risk of infection is especially great in winter, when horses have dense winter fur and are washed relatively infrequently. 

What is ringworm?

Ringworm is a skin disease caused by a type of mould; dermatophytes. The most common dematophytes that cause ringworm in horses are Trichophyton and Microsporum.

Symptoms of ringworm in horses

The symptoms of ringworm can look different depending on the stage at which it is detected. Minor swelling of the skin and crusts that form are usually the first symptoms. When the crusts then fall off, the symptoms become more visible with hairless and dry round areas of varying sizes. Sometimes there is also thickened skin.

Affected areas are usually the head, neck and trunk. The areas affected can vary depending on which body parts have come into direct contact with infected horses or with infection from borrowed equipment.

Horse affected by ringworm. Photo: Carin Wrange

Treatment of horse with ringworm

Ringworm often heals on its own even without treatment. However, your vet can prescribe antifungals to speed healing and to reduce the risk of ringworm infection.

Horses that have undergone infection often become immune for life unless there is a type of ringworm (strain) that is far removed from previous infection. This is why young and old horses, as well as horses with a weakened immune system, get ringworm infections more easily.

Sanitation and cleaning

In parallel with treatment against ringworm, the stable and all equipment are also cleaned. Due to the high risk of infection, it is important to be thorough and clean everything from the stable interior to the brushes.

Isolation

If there is the slightest suspicion that one or more horses have been infected or found to have ringworm, they must be isolated immediately to avoid the spread of infection.

How is ringworm transmitted between horses?

Ringworm is one of the most contagious skin diseases in horses. It can be transmitted directly between horses and indirectly via equipment, furnishings, clothing, the environment and riders. The disease is so contagious because the fungal spores formed in connection with the infection can survive on equipment or in the stable environment for months to years and infect more horses much later. Ringworm can also infect other animal species and humans.

Source:

SVA – The Norwegian Veterinary Medical Institute.