A condition called scratches is also called mud fever as well as other names, but the actual name is equine pastern dermatitis, even though it can occur further up the leg than the pastern. It is commonly seen on the back of the horse's pastern area and at the front of the cannon bone on the rear legs. When feeling the affected area, you will feel small bumps on the skin. These are scabs with infection underneath and are usually due to some type of irritation. The scabs are very painful to remove and although there are multiple causes, the most common cause I believe is allergies, especially to flying insects like mosquitoes. Regardless of the cause, something irritates the skin and leads to an infection and a scab.
To treat the condition, all hair should be removed carefully with clippers to avoid further irritation and all scabs should be gently removed. As mentioned, removing these scabs is painful and many horses will require your veterinarian to sedate them for scab removal. I usually soak the scabs by shampooing with an antibacterial shampoo and leave that on the skin for 15 minutes. This will soften the scabs and make removal much easier. The antibacterial shampoo can be used daily or every other day to kill infection and prevent scabs from forming. After the scabs are removed, topical treatment with an antibiotic and steroid cream is used to kill the infection and prevent more scabs from forming. If the infection is severe, oral antibiotics may be needed. Using a shampoo and ointment containing chlorhexidine is effective as it is antibacterial and antifungal. Preventing scratches involves keeping the legs dry, and if flying insects are the underlying cause, control those.
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