After another troubled night this morning we've carried him downstairs and placed him on a soft rug by the front door where he can watch his big brother and breathe fresh air. That way he's where he'd want to be - at the centre of everything that's going on. He's sleeping more and more and becoming less and less interested in what's happening around him. We'll go back to the vet later this morning to see if there is anything else that can be done.
Thank you so much for all your kind thoughts and prayers. They have been heartwarming . Doubly so as they come from folks we've never met and yet who still take the time to care.