I am no vet, and this advice is possibly worth what you are paying for it. We used to turn all of our sheep in a sideways turning crate in the week before Christmas when they were due to lamb from March 1st. I don't remember any truoble, obviously we were calm and cool about the whole thing with the sheep.
Much better to deal with the blighters in the lambing pens after lambing we think now although by then some may be a bit too limpy to send outside straight away. If you can't wait try a footbath - make them stand in it or at least run them through a time or two and stand them on dry concrete (if you have some - I have) for a half an hour or so to let it soak in.