The primary medicinal ingredient in this blend, Wormwood, is a well-known and effective vermifuge. It has been recommended for treating a variety of worm infestations. The blend also contains Black seed, which, when combined with Wormwood, is especially effective in killing and expelling parasites including roundworm, tapeworm and hookworm. D-wormer can also be used to control fleas and lice. All of the herbs in this blend work together to improve digestion and to ensure your pet is healthy and free of parasites!