Thank you, Anke. I have had fatty liver disease mentioned to me before but I'm disinclined to think that this is the problem.
As to concentrates, the answer is no - except in the run up to and the period after lambing. My sheep spend the summer on grass with only a little grain to keep them coming to my call.
Compared to a fortnight ago, the ewe has exceeded all my expectations. She's alert, steady on her feet, regained her strength, eating good quantities of hay, supplemented by Sodilene morning and evening, ruminating and drinking water of her own volition. Hopefully soon I'll be able to turn her out onto grass during the day - although I'll bring her in at night because, in the last two days, winter seems to have arrived in earnest in my part of the world.