Feline hepatic lipidosis. Late-ish stage. He was jaundiced, but hadn't had any seizures that we know of.
Don't know yet if the liver damage is reversible, but I'll be going to see Gord at the vet's tomorrow, or Saturday morning if I can't get there sooner.
Poor little guy. He must be so scared, but I don't want to tease him by showing up and then LEAVING him there, but I want to see him and hold him, but but but.
How did I miss this? How did I not guess something was seriously wrong, when he stopped being his regular noisy, bossy self?
Fuck.