Scratches is the common term for pastern dermatitis, an inflammation of the skin that develops between the heels and the fetlocks. Affected areas become scabby and crusty, sometimes oozing clear or yellowish serum.
Usually the result of repeated wetting and drying, scratches develops when bacteria or fungi invade through tiny wounds or cracks in the skin’s surface. Although scratches can occur at any time of year, it is seen more frequently when horses are turned out in wet environments.
You can probably treat scratches on your own, and most cases will clear up quickly with proper care. But if your horse develops persistent or severe scratches you’ll want to seek your veterinarian’s help.
Here’s what to do:
• Rinse your horse’s legs. Move your horse into a dry area, and hose off dirt, mud and other debris on his lower legs. You may want to carefully trim the longer hair on his pasterns to better expose the skin to the air.
• Cleanse the affected area with an antiseptic wash. Choose a product that contains 2 percent chlorhexidine or benzoyl peroxide, and use it as directed. Avoid products with higher concentrations of these agents because they can further irritate the skin.
• Dry the skin thoroughly. You may want to use a hair dryer at a low setting.
• Apply an antibiotic ointment. This step isn’t strictly necessary, but in addition to helping to kill bacteria, a thicker ointment may form a protective barrier over the skin.
• Repeat as needed. Clean and treat the affected skin every two to three days until the infection clears. Most cases heal within two weeks.
• Address the cause. If your horse developed scratches after spending too much time in wet turn--out areas, you may need to find him a drier paddock or pasture. Also consider longer term solutions, such as laying down gravel in chronically wet areas or taking other steps to improve drainage.
It may take some detective work to discover the cause. Scratches may develop when a horse’s skin is chronically irritated by bell boots that don’t fit or environmental conditions such as coarse arena footing. In other cases, the skin is irritated by chemically treated bedding materials.
Call your veterinarian when:
• The infection grows worse despite treatment or does not heal within two weeks. Your veterinarian will want to rule out other conditions, such as vasculitis0 or mange0, which can look very similar to scratches. In addition, a prescription medication or a different treatment may be needed if the infection proves to be fungal rather than bacterial in origin.
• The affected legs start to swell. If pathogens penetrate the outer layers of the skin, a serious infection of the deeper tissues may result, leading to painful swelling. You’ll want your veterinarian to begin treatment promptly.
• The infection recurs persistently, despite treatment and changes in the horse’s living conditions. Some horses are just more prone to scratches. But if yours seems to be constantly affected when others around him are not, your veterinarian will want to investigate the reasons why. One possibility is that your horse has an underlying disorder that affects his immune function.
This article was originally published the March 2016 issue, Volume #474 of EQUUS magazine