I have used this paste successfully for two different issues. The first was on a horse allergic to a certain fly in WY. As long as the horse was on the Proteqtor, he didn't swell up. The second use was for old mares on Prascend to get rid of and keep rain rot from coming back. The Prascend seems to depress the immune system and this product gets that protection back. Love this product! Have always used the paste, but going to try the powder to cut down on the barn chores.