Back from the vet.
Jakey's not in a great state bless him, which we knew, he's lost more weight and we've got some tablets for the constipation (which is moderate, the vet says he's seen a lot worse cases, which is at least something) and we're going to start giving him fluids every day instead of every other day to see if that all perks him up a bit. His eyes are gunky due to dehydration and the vet suggested I get some artificial tears from the chemist which will make his eyes more comfortable.
However if there's no sign of improvement within 48 hours we have to seriously consider the value of further intervention and might have to decide to call it a day.
It's upsetting of course, but tbf I've been in a state of expecting it at some point for the last couple of months.
And there's still a chance that with increased fluids and unstopping his bowels a bit that he might have another month or two of happy comfort, which is worth a go.
I don't think he's miserable and CKD is not considered a painful condition, but he is definitely tired and frail on the days he's not been having fluids, so giving fluids every day might help a bit, and we can judge whether that's improving his quality of life substantially and therefore making his life worth living - thankfully he is so easy to give fluids to, it doesn't bother him at all, we do it while he's eating and it just takes probably about a minute.
I actually think he'll let us know when he's had enough, and stop eating - that's the way it's been with the others.