I wouldn't normally blame the corvectI just trim and spray. I lost 1 lamb and 1 ewe this year... but I put that down to how badly they were eaten into by time they showed signs and I caught them I didn't blame the Crovect
either but they weren't bad patches of maggots or eaten into even just skin deep. I'd done much worse than them with it before and they were fine it was just that one time when what I did treat died. I asked the vet when he was here doing something else if the crovect could have done something to them and that was what I was told could have happened. I'm not the only one I've spoken to that has had it happen but maybe we have just been unlucky