One of the other side effects of this disease is very low fertility, we had this last year. My heart goes out to you Captain, it's not good and there is nothing we can do about it except carry on.
My ewes that have had SBV lambs we've put them out in a spare paddock after jabbing up with antibiotics, luckily they've come through it ok and seem very bright considering the way we pulled them about getting the lambs out. I was worried we had holed them but it would have shown by now. Nothing like Doctor green grass to get them interested in life again.