Hi, I am just finding this site and was reading an article and plea from someone whose cat is starving herself. Not sure if you will read this, but anyhow.
My cat has done this several times in his life due to me moving. He will starve himself and I have to force feed him. Doesn't sound quite the same to me though. His liver actually shut down after two weeks 6 years ago and the vet had to put a feeding tube in his neck. It worked! His liver started to regain its strength after about 3 weeks of tube feeding, than he took over himself. I am not sure if your vet has any Science Diet A/D perscription diet canned food, but that is the only thing my cat will eat when he gets like this. I am actually going through this again with him, but know what to look for now. I also have gotten appetite stimulators for him, however, they make him groggy and wobbly. He isn't too social when he has them either, but he does eat, which is more important than socializing at this point.
Good luck to you and hope both our friends start eating on their own shortly.