Zimecterin Gold combines ivermectin and praziquantel to provide the broadest spectrum of parasite control available for horses. Praziquantel is proven to have a wide margin of safety and to be highly effective for controlling tapeworms in horses. Zimecterin Gold is appropriate for used in horses 2 months and older. Plus, ZIMECTERIN Gold was the first dewormer approved by the FDA to effectively control tapeworms with a single dose. Tapeworms have been recognized as a significant threat to the health of horses.