Ringworm
What is Ringworm?
Despite the name Ringworm is not caused by a worm but by a fungal infection. Ringworm is highly contagious but usually only causes mild discomfort to affected animals. It is spread by either direct contact with an infected horse or indirectly by contact with objects carrying the spores such as infected tack or grooming kit. Although Ringworm can be seen in horses of any age it is most commonly seen in young horses as older horses can build up immunity against the infection. Humans can also catch Ringworm from infected animals. There is a delay of 1- 3 weeks between infection and first sign of the skin lesions. This is one of the reasons the disease can spread quickly as the infection can develop and spread unnoticed.
What are the signs?
The lesions first appear as a small raised sore, which then develops into an area of scaling and hair loss. The areas are not usually itchy. The lesions can spread across the horse as the spores can be carried by brushes and rugs.
How is it diagnosed?
Patches of scaly skin and hair loss are typical signs of a number of skin diseases (such as Rainscald) so in order to try to confirm diagnosis of Ringworm samples of hair may need to be taken. These hair samples will be examined under a microscope, where we can often visualise the fungal spores. The hair samples may also be sent to a laboratory for culture of the fungus. Results can take 1-2 weeks so whilst waiting for the results it may be wise to treat your horse as if it does Ringworm until proven otherwise.
How is it treated?
Any horse suspected of having Ringworm should be prevented from making direct contact with other horses. It should have its own tack, grooming kits etc and these items should be thoroughly disinfected as spores can survive on them for several weeks. The lesions themselves are treated with a fungicidal wash. If the lesions are more extensive or lots of horses are affected then the oral treatment may be given instead.
If left untreated Ringworm will usually resolve itself within about 1-3 months but by this time the infection may have spread to other animals and people.