I read a rather lengthy post on the pros & cons of various wormers. I haven't seen any worms in the girls, but it has been a wet summer and they spend a lot of itme free ranging. Since I have so few hens, I really don't want to scrap the eggs for 2 weeks and thought I'd try Fenbendazole (SAFEGuard). Randall Burkey carries it- it says it's for cattle, so how would I know how much and how often to give it to 7 chickens?