Ringworm is not actually a worm, it is a form of dermatitis that is caused by a fungus.

Tails from the Barn -- by Carol Gosselin

I took this picture of a scab-like formation that I found on the mare I help to take care of. It’s Ringworm and I wanted to learn more about this skin disease.

Photo by Carol G.

Ringworm -- What it is and is not
Ringworm is not actually a worm, it is a form of dermatitis that is caused by a fungus. Also known as Dermatophytosis in horses, this form of dermatitis can affect all kinds of living beings from dogs and cats to horses and people.

Ringworm is known as a Zoonotic (pertaining to Zoonisis) disease. Zoonotic diseases are diseases that can be transferred (Zoonisis) from animals to people or more specifically, a disease that exists in animals but can infect humans. There are a great number of Zoonotic diseases, such as Anthrax, Lyme disease and Rabies to name a few. The lesions are typical enough that the skin condition can be diagnosed by eye, which is how we diagnosed it on our mare.

Where it lives
This fungus likes to live on the warm, moist surface of a horses’ skin or hair and is not choosy about what part of the horse it lives on. The face, neck and girth are the most common areas but can cover the entire horse in severe cases.

Photos below, credits www.horsejournals.com

While a horse with ringworm may be uncomfortable, (itchy), ringworm is really more of an unsightly nuisance than any sort of harm. It may disappear on its own weeks or months after the initial outbreak.

Treatment
Ringworm is pretty easy to treat and clear up. It may disappear on its own weeks or months after the initial outbreak. But in the meantime, ringworm can spread to other horses, humans and pets as the fungus can persist on stall walls, brushes, tack and other items the horse may come in contact with. The good news is once a horse has had ringworm, it is unlikely it will get it again.
Treat the horse with an anti-fungal wash. Some vets may suggest shaving the area. Because the fungus will persist on the horse's brushes, tack and barn, all should be washed down with an anti-fungal solution to prevent further spread. It's important to wear gloves during the treatment time and take care not to pass the fungus on to other people or animals.

Prevention
Keeping your horse in good health is the key to avoiding many problems. It is a good idea for each horse to have its own tack and brushes. If ringworm is suspected, the horse should be kept away from others until the lesions disappear.