Global herbs skratch plus is based on extracts of certain trees which soothe the skin and help the body tolerate flies midges and other insects and parasites skratch plus generally has a strong smell which flies and parasites do not like this can make the formula less palatable but once your horse has become accustomed to the unusual taste the product gets to work very quickly this severe itch formula is an essential mix to use whenever your horses skin is a worryhow to use introduce gradu