A dandy brush, also known as a stiff brush, is used to remove dirt and hair that was loosened by using a curry comb. It should be used with short, stiff strokes and can be used all over the horse’s body, including the face and lower legs. It is often used on the mane and tail. Be careful when using a dandy brush around the horse's face and lower legs because these are less-muscled areas and may be sensitive.
For more information about grooming, check out How to Groom a Horse and Grooming for Success.