Well I know it has a my dookit Geordie last year between old birds and young birds I lost 18 birds . I worked hard all winter to help my pigeons this year I have not lost a bird from top of loft doo men have to help them selfs before anybody will help us .just like anything that harms the pigeons .canker/cocci/worms/or anything only the doo man (fancier) can sort it out .J.M.O.