imecterin Paste Horse Wormer (1.87% Ivermectin) is the original patented formula of ivermectin paste provides parasite control for 60 species and stages of parasites in horses, nearly twice as many as claimed by generic equivalents. This combination anthelmintic and boticide is effective against bots, large strongyles, small bloodworms, ascarids, bots, threadworms, pinworms, hairworms, lungworms and large mouth stomach worms. Proven safe for pregnant mares, breeding stallions, and any age foal. Each syringe treats 1250 lbs. of body weight. Syringes are adjustable in 250 lb. increments.