An oatmeal bath is a soothing option for horses suffering from dry, itchy skin. To prepare an oatmeal bath, grind plain, unsweetened oatmeal into a fine powder. Add the powdered oatmeal to warm bath water and let your horse soak in it for about 15-20 minutes. Oatmeal is known for its anti-inflammatory properties and can help relieve itching and discomfort.