Turn into a shitty-arsed muck magnet?
It can't be nice for them, to have all that extra weight round their backsides. Having seen the damage flies and maggots can do, I try to make sure I have all the dung off them but it can be difficult if they don't stand still. If you nip them with the scissors then they do tend to leap about a bit, and I can't say I blame them.
