Hi, I found one of our two week old tack lambs lying flat in the field on Friday afternoon, freezing cold, barely moving, eyes glazed over, laboured breathing, thought he was dead. That morning he had been running around with the other lambs normally. I brought him in to the kitchen, warmed him up and we gave fluids by syringe every hour to rehydrate him for 24 hours. By then he was standing and bleating but very disorientated and couldn't walk, just suddenly fling to the side and roll right over. He was also teeth grinding and pressing his head into the corners and occasionally convulsing. I started him on Lamlac which he suckled a bit half heartedly and would only take 150 - 250ml at a time, sometimes quite alert, sometimes just lying spaced right out. Saturday night he wouldn't feed and was totally blind, crashing into things as he stumbled around. I did some sight tests and there was nothing. Sunday morning he was bright and bleating and running around not bumping into things looking normal. Put him in the stable with the ducks and he chased them round. By the afternoon very dull, head down and the feeding has become more forced. He's been passing urine and solids regularly. At the moment he is just lying looking zoned out, not interested in anything. I'm confused. I keep thinking he'll not make it then he brightens up. The closest diagnosis I can see is Thiamin Deficiency from symptoms but wouldn't expect him to brighten up?