I use wormazole liquid. It gets round, cecal and tape. Just a few drops per lb. in each bird orally and I'm sure they got it and it's easy. I do this a couple of times a year. I too use cayenne thru the winter and lay off the wormazole. I understand that cayenne works also if blackhead has started in turkey. If caught within the first 24 hrs. (you will see sulphur colored poo) it's supposed to be treatable with lots of cayenne. Haven't had this happen but I do use it as a preventative. I heard that cayenne is not good to use so much in the hot months because it causes the chickens core temp to rise.