Horse Disease Focus - Ringworm
What is ringworm?
Ringworm is a skin infection that affects multiple species, including horses and humans. It is fairly common and is also known as tinea or dermatophytosis.
Ringworm produces small circular patches of hair loss with scabbed or flaky skin. If untreated, they grow into large areas of broken hairs and blisters. It is most commonly seen around the girth and saddle area, face, eyes and legs.
The lesions can be unpleasantly itchy and the horse may cause further damage to its skin by scratching. Also, they offer an opening to other skin infections. Because of this, ringworm must be treated immediately.
Before treatment, your vet will take a culture to confirm ringworm (rain scald can present very similarly, but is treated differently).
Ringworm is normally treated topically, and several treatments are available. Your vet will advise you as to the best one. In some cases, more than one treatment will need to be tried and stubborn infections may require pills in addition. Before treatment is applied, the affected area should be cleaned using a mild detergent and either a nylon scouring pad or toothbrush. (If the skin is actually raw, then hold off on this until a few treatments have been given). The skin should then be thoroughly dried and kept dry.
As ringworm is highly contagious, a horse with ringworm should be completely isolated. All grooming equipment and tack used on the horse should be disinfected thoroughly. Although ringworm does not technically preclude work, as ringworm lesions are commonly seen in places where tack is applied, the horse may need to be rested until the lesions are healed.
Ringworm is also contagious to other animals. Barn pets should be kept away from the infected horse and anyone who handles it should wear gloves and wash their hands thoroughly with disinfectant after handling. Ringworm in humans generally presents as an itchy rash and the typical circular lesions may or may not be present. Most commonly, if you do pick it up, it will be on your hand. Your doctor can confirm the diagnosis. Human ringworm is usually treatable by use of over the counter anti-fungal creams. If those do not work, then your doctor will likely prescribe an oral treatment.
Ringworm is most commonly seen either in young horses (under three) or older animals. It also tends to show up in animals with chronic conditions. A horse that has had ringworm will become immune to it for an extended period of time.
The best prevention measures are to isolate new horses for two to three weeks. Ringworm also likes the cold and damp. Drying horses thoroughly when they come in from outside, especially in winter, goes a long way towards preventing the condition. If a horse comes in with ice or snow on its back, it should be brushed off immediately before it has a chance to melt, in order to prevent both ringworm and a bacterial skin infection called rain rot. Horses can handle dry cold better than wet. (As a side note, if most of the horses have ice or snow on them, any that do not should probably get rugs - those are the ones who don't have enough winter coat to insulate their body heat).