Eqvalan (Ivermectin 1.87%) Paste treats a wide variety of internal parasites in horses of all ages, pregnant mares, and breeding stallions. Eqvalan dewormers use ivermectin to treat large and small strongyles, pinworms, ascarids, bots, lungworms, large-mouth stomach worms, Summer sores, and more. Eqvalan is usually effective with just one oral administration.