Selamectin is a topical parasiticide and antihelminthic used on dogs and cats to treat and prevent infections of heartworms, fleas, ear mites, sarcoptic mange, and certain types of ticks in dogs as well as prevent heartworms, fleas, ear mites, hookworms, and roundworms in cats. It also removes 2 types of lungworm in cats and one type of lungworm in dogs. It is distributed by Zoetis, a former Pfizer subsidiary. It is structurally related to ivermectin and milbemycin. Selamectin is not approved for human use.
belongs to the class of organic compounds known as milbemycins. These are a group of macrolides with a structure containing a 16-membered lactone ring fused to a 1,7-dioxaspiroundecane ring system and to either a benzofuran (or hydrogenated derivative thereof). In some cases (e.g. Milbemycin E), the tetrahydrofuranyl ring is missing. Milbemycins can be o-glycosylated at C13 to form Avermectins. Milbemycins are produced by Streptomyces species.