DurvetTreats and Controls Adult and Fourth-stage Larvae of: gastrointestinal roundworms, lungworms, and all larval stages of nasal botInteded for use in sheep8 fl. oz.001-1067 Protect your sheep from parasites with this Durvet Ivermectin Sheep Drench. Ivermectin Sheep Drench provides treatment and control of adult and fourth-stage larvae of gastrointestinal roundworms, lungworms, and all the larval stages of Nasal Bot.Durvet has made the commitment to being your premier supplier of high quality animal health care products. And, they've taken that commitment one step farther. It has become their mission. They ensure their products and services result in Healthy Animals, Healthy Savings and Healthy Value.