Also known as pastern dermatitis and grease heel, scratches is a skin irritation commonly associated with draft horses and other breeds with long feathers, though it may also occur in those with very little fetlock hair as well. It occurs most commonly as scabs on the back of the pastern and fetlock joints, and occasionally up the legs on the hocks or knees. These scabs may be sensitive if picked at, and depending upon the severity, may break open and ooze serum and blood. These scabs and open sores can be painful and some horses may go lame with serious cases, as well as show heightened sensitivity around the area(ie: watch out when picking hooves and bending the afflicted area). Although not a rule, it often is worse in those horses with very thick fetlock hair. Signs that a horse may have scratches include itching the afflicted area with the teeth, or with a hoof (often you will see them rubbing one back leg against the other).
In Friesians it is acknowledged as a common complaint and most will likely contract it at some point, though it occurs in varying severity depending upon the individual. The actual cause of scratches isn’t known with any real certainty, though there are varying theories, and the most likely explanation is that there are multiple causes for variations of the affliction. Many believe it is associated with a wet and unclean turnout or stall area where the horse must stand in unclean mud or muck for a long period. It may also be caused by mites or bacteria.
Just as there are many theories to it’s cause, there are many theories on how to clear up a break-out of scratches. If scratches is a chronic occurrence and needs treatment regularly, it is often recommended to shave the back side of the pastern to allow the area exposure to air and easy treatment. (Don’t worry..if the horse has thick enough hair, this can be done without shaving off those trademark feathers. Shave only the center of the pastern where the scratches occur and leave hair on the sides to cover the patch.)