Protazil®Protazil is the first FDA approved alfalfa based, pelleted treatment for equine protozoal myeloencephalitis (EPM). Active Ingredients: 1. 56% diclazuril Product Information: One 2. 4 lb pail of PROTAZIL will treat one 1100 lb horse for 28 days. This product is made for Merck Animal Health Directions for User: PROTAZIL (1. 56% diclazuril) is administered as a top dress in the horses daily grain ration at a rate of 1 mg diclazuril per kg (0. 45 mg