Top dress Solitude on horse feed. No matter the size or age of your horse, you feed 1 scoop per day. (1/2 oz per day). The cost is about 50 cents per day per horse. As the horse is fed cyromazine, it passes through the horse and is excreted in the manure. House flies and stable flies lay their eggs in the manure and the eggs subsequently hatch into the larval or maggot stage. (Cyromazine has no effect on the chitin of the adult fly.) As the maturing maggots feed on the manure treated with cyromazine, they become unable to successfully develop into adult flies because cyromazine inhibits the proper formation of chitin. The immature stage of the fly dies.