Blotchy, bloaty axolotl - sick or just old?

Hi friends,

My golden albino axolotl, Chester, has these orangey-brown spots that have grown over time (years? see photo). I asked about them once before on this forum and someone attributed them to old age; he's now older (8 years and some change) and they are multiplying.

At the same time, he also seems to be either getting fatter or bloating; this is happening slowly so I can't pinpoint a date, but he seems rounder in the belly than he used to be. He has eaten live earthworms and lived in a tank with fine sand for his whole life with me; he's still eating fine.

Between the spots and the roundness I'm worried that he might have some kind of liver issue or might have a blockage -- or is he just getting to be a fat old man?

Any thoughts would be appreciated, especially from caretakers of older axolotls! Thanks!

Hi everyone, his condition hasn't changed much even after 2 weeks in the fridge, so I took him to see a vet today. $120 later I don't know much more, except that there isn't a blockage in his digestive system. Both a reptile vet and a part-time vet for a zoo that has axolotls looked at him, and they did an x-ray and an ultrasound. The most they could say is that there is general fluid buildup and they weren't able to pinpoint why.

Looks like he may be nearing the end of his days, but any suggestions as to other things to try, or just how to make him comfortable would be appreciated!

Thanks!!!