Now I've got myself in a right stew, googling the symptoms and finding some plants can cause them - apparently he was out in the garden much of the day at the sitters' house.
He is doing the weird hallucinating thing even more now, his pupils are dilated and not reacting to light, his tummy is gurgly, every time he tries to doze off he jumps out of his skin and wakes up again.
DOn't know whether to call a different vet for a second opinion - what do you think? sooo worried