Ringworm in Horses

Horse ringworm, also known as girth itch, is an unsightly, although common, winter skin ailment.  Ringworm is caused by a fungus and can be a source of stress for horse owners due to the unattractive skin lesions it causes and the time consuming efforts required to treat and control it.  The fungus typically enters the body via a break or tear in the skin, such as a minor scratch, allowing it access to invade your horse’s hair follicles.  Once in the follicles the fungus begins to breakdown the skin cells in a circular pattern, causing the well-known hair pattern associated with ringworm.  The most common type of ringworm horses contract is Trichophyton equinum but since ringworm is not species specific you or your horse can get ringworm from other animals on your farm such as cows, cats or dogs.

                The direct cause of ringworm is a fungal infection, but there are certain conditions that can increase your horse’s risk of catching or transmitting it.  The close quarters that horses often keep during cold months can cause a huge increase in the incidence of ringworm on your farm.  The skin-to-skin contact that may occur with animals being housed together allows for the fungus to easily transfer between animals.  A stressed animal is also more likely to develop a ringworm infection.  Keep this in mind when traveling for shows or training.  Young, sick or immunosuppressed animals may also be more susceptible to a ringworm infection.

                Horse ringworm commonly starts as a small patch of dry, scaly skin which grows to larger circular lesions.  If these lesions are draining or open it can allow bacteria to enter, complicating the infection and treatment of the area.  Most horse ringworm infections originate from the face, neck or girth area but this can vary depending on the type of fungus.

 

                There are multiple skin infections that can look like ringworm, so if you suspect your horse may have it a vet visit is in order.  The vet will be able to determine if it is a true ringworm infection using a Wood’s lamp or doing a skin scrape/culture.  It is important to get a proper diagnosis from a vet because the wrong type of medication may make the condition worse.

                Treatment of a ringworm infection is a multi-step process.  The vet will typically prescribe a topical anti-fungal cream but the use of medicated shampoos can dramatically decrease the duration of the infection.  Shampoos containing lime-sulfur, iodine or chlorhexidine are shown to be very effective in treating a ringworm infection.  These treatments will most likely need to be repeated daily, then weekly until the ringworm has gone and the vet has medically cleared your horse.  To avoid reinfection disinfect all combs, brushes, tack and blankets after each use.  Disinfect stalls of infected horse.  Bleach water solutions (10:1) are great at killing fungal spores.  Untreated fungal spores can live on surfaces for up to a year!  Keep uninfected horses separated until treatment of infected horse is completed.  Also keep your horses skin dry and clean, allow for lesions to dry out.

                Since ringworm can be transmitted to other animals (including humans) it is important to use good sanitary practices when handling your infected horse.  Use gloves when applying treatment or sanitizing tools, try to refrain from hugging your horse until the infection has cleared and wash, wash, wash your hands!!