Scratches is a term used to describe a frustrating, chronic, crusty, painful condition of the horse’s lower limb. It goes by several other terms, too, such as pastern dermatitis, dew scald, mud rash, and greasy heel. The skin condition is often infectious, caused by damaged areas of the skin that get infected by bacteria, viruses, and/or fungus that is concentrated in mud. It can also be caused by inflammation in the skin caused by the immune system mistakenly attacking the skin or the blood vessels in the skin.
To treat scratches, the first step is to keep the area as clean and dry as possible. Clipping the hair helps to keep the skin clean and to allow it to dry faster. Wash with a prescription shampoo that kills bacteria and fungus and dry thoroughly, either with a towel or hairdryer. Especially at first, some sedation may be needed, as the crusts can be very painful. Applying an antiseptic cream, such as diaper rash remedies, will help soften crusts, kill infection, and protect the area from re-infection. Some horses benefit from a day or 2 of anti-inflammatory medicine, such as bute.
If this treatment does not adequately address your horse’s scratches, there may be a more serious underlying problem. Please call your veterinarian, who may perform diagnostics such as biopsy and prescribe further treatments.