There’s a Fungus Among Us! (And Other Icky Horse Skin Conditions)

Posted by Carolyn Adams, Mon, May 20, 2013

We’ve all been there: You go out to see your horse and…what the heck! Your buddy is looking crusty and missing hair! Horse skin conditions are a common frustration among horse owners. They can be caused by a variety of things including fungi, bacteria and insect bites. They can be difficult to diagnose, but the good news is that most common fungal, bacterial and insect-related conditions often respond to topical treatment, which is great because oral systemic treatments can be extremely costly.

One type of common fungal condition is commonly mistaken as a parasitic infection due to its deceiving name. Despite its common name, ringworm is actually a fungus which can affect multiple horses in a herd. Fungi are primitive plants that reproduce by sending out spores in moist environments. They love warm, humid areas and wet seasons. 

Ringworm in horses is very easily transmitted among animals by sharing equipment such as tack, brushes or blankets. Often the lesions will be found in the saddle or girth area. Ringworm is one cause of the condition commonly referred to as “girth itch.” This is when the lesions appear in the girth area, causing sore, irritated skin. Girth itch can progress to causing very large sores, making it impossible to ride the horse until the area is healed. Ringworm in horses usually appears as a crusted circular lesion. The skin will appear dry and flaky and the hair will often fall out to reveal a ring of baldness—hence the lovely name ringworm. At other times the reaction will look similar to hives. Ringworm can most effectively be avoided by carefully disinfecting, or simply not sharing, tack and equipment among horses. When a lesion is noticed, topical treatments can be effective.

A second type of common skin condition is called rain rot, also known as rain scold or dermatophilosis. This skin disease is actually caused by a bacterium called Dermatophilus congolensis, which does well in wet conditions and enters through damaged skin. Rain rot is usually most prominent over the horse’s top line, so you may notice it along your horse’s neck, back and tail area. The affected area usually appears as raised crusty clumps of hair which usually fall out, leaving behind bald patches. Rain rot is very contagious, so be careful not to cross-contaminate your herd. Disinfect equipment or strictly avoid sharing it among horses. Rain rot often affects horses with compromised immune systems as well, so if your horse appears to be affected by rain rot it is always a good idea to check in with your vet.

Scratches is another common skin condition related to moist conditions. It usually affects the area under your horse’s fetlock and appears as moist, gooey, crusty scabs and hair loss. Breaks in the skin due to irritants such as allergic reactions, mites, or other irritating exposures allow bacteria or fungi to enter the compromised area. If your horse spends a lot of time in a moist or muddy environment, this can lead to secondary bacterial or fungal infections. This condition is also known as “greasy heel.” Horses with feathered legs, such as draft breeds, seem to be more susceptible. Try to keep your horse in a clean, dry environment to avoid this condition. If you do suspect that your horse has Scratches, clean and dry the area thoroughly. Often clipping the area can greatly speed up the healing process by allowing it to stay drier.

Sweet itch, or Summer itch, is a reaction to the bites of tiny gnats (often called “no-see-’ems”). The horse’s reaction to the bugs’ saliva causes small, itchy bumps on the skin. Often the horse’s mane and tail head are most affected. While the bites themselves do not cause a lot of damage, the horse will be extremely itchy and scratch on anything around, resulting in scabs and sores.

Good barn and horse hygiene can help prevent most of these frustrating horse skin conditions. Keep your horses in clean, dry environments. This may mean keeping them out of muddy pastures or turnout areas during the wettest times of the year. If you have no choice but to turn them out in wet conditions, make sure to clean your horse up after turnout including a quick rinse and then allowing them to dry in a clean environment. If you do notice that your horse appears to have a nasty skin condition, remember to avoid cross-contamination among horses (isolate your horse and do not share equipment). Clean equipment using diluted bleach. Bathe the affected and surrounding areas with an anti-fungal or anti-bacterial shampoo, then towel dry or air dry thoroughly. Clip the affected area if needed, but don’t forget to disinfect your clippers and blades afterward!

Following a good cleansing, use a topical treatment such as Corona® Fung-A-Way. This outstanding topical fungicide aids in the control of several fungal infections including ringworm, summer itch, girth itch and other horse skin conditions. Its non-staining formula also contains allantoin, which helps protect and soothe irritated skin.