Thanks- he seems to be a lot brighter, holding down water and back to his stressy self! He had a long walk in hand (hour and a half) just to stop him stressing in the stable and the vet finally called back. He's gone out on the poor grass with ad lib haylege (very wet) and when I left he was eating. Have got someone checking him later for me and i'll leave work early to check him this afternoon.
Thanks for your get well wishes. The threat of the GA must have worked!
Also i think he had a complex as two people told him yesterday that he looks smaller when he is poorly and I don't think he liked hearing that!