Friend's kitty : domestic short-hair, 3-5yrs old if I remember, male - unsure if he's neutered or not... sorry for the lack of info, but he's not very social and I'm not around him much.

Just got a new kitten, female, not spayed yet. Introduced her (Sydney) to him (Riley) - everything went great. He's taken the role of her protector, so to speak - doesn't let just anyone get close, grooms her, they play well, etc.

A month after introducing Sydney to Riley, Riley stopped eating. From what I understand, by fasting, he began metabolizing fat stores (which he had a lot of, used to weigh 17lb)... his liver got gunked up, and developed jaundice. (He's been tested for a ton of stuff, nothing came up at all.)

I'm not sure if there's a color scale or what, but when they took him in to the vet, he had yellowed just to the point where he was peachy colored, not at all the bright pink he was before. He was in for 2-3 days, and turned TENNIS BALL YELLOW. (I thought he was dying for sure... never seen jaundice like that!)

The vet's office had placed an IV for dehydration and had been force feeding - they placed a G-tube at this point. As he got sustenance in his body, his jaundice faded a bit over the next few days. At the end of the week, with the help of appetite stimulants, he began eating on his own - the IV was removed and he's been sent home, 8lb lighter. He's going to finish what's left of the appetite stimulants and antibiotics he was prescribed.

Now that he's home, he's not eating as well as he was. The jaundice has not gotten worse, but has stopped improving. Friend is concerned that Riley will end up back in the vet's office, and the cycle will continue until his liver craps out. She'd really like to be able to come up with a Dx, her kids (3&5) are stressed, wondering where their buddy is - and she doesn't want to have to go through too many $1200/wk stays at the Kitty Kat Ritz before she gets it figured out... or worse, he dies anyway.

While I was there, we noticed that he's lost all interest in wet food, only eats the dry stuff (which he used to turn his nose up at) one or two bites at a time. He does it almost with disdain, like it's a chore... I wonder if for some reason his sense of taste is distorted. You'd think if it was painful to chew or swallow, he'd stick with the wet food he's always relished?

Questions:

Why the antibiotics? Just precaution?

Reasons that he would stop eating? We've looked at environmental factors, but cannot find anything. He's indoors only. Maybe we've missed something?

Any off-the-wall things to test for, that maybe her vet wouldn't think of?

Any other suggestions are greatly appreciated. Forgive me for forgetting the names of the meds he's on, I can get the names and any other info from my friend if it's relevant.

Thanks!