Thanks, again for all the responses.
A little background: he was diagnosed with FD in late 2009, went into remission March 2010 by switching to Friskies Mixed Grill, was off insulin until recently. In the meantime, a year ago this time of the year got very ill with some mystery illness, stopped eating, but diabetes still in remission. He came to life when I switched his food to the Fancy Feast Elegant Medleys Chicken Strips with Garden Greens Fare (or a name like that). At first I had to feed it with a spoon, but eventually he recovered fully and had a great year. His labs, x rays, and even ultrasound were normal except for a small lymph node, too small to biopsy. He did wonderfully until he had a relapse on his diabetes, around December, was re-started on insulin in January, it's been much harder to control. I tried to go back to the Mixed Grill but he didn't want it, after trying out different foods, settled for the Fancy Feast Chicken Classic and he seemed to be doing OK on it for a while, but about a week ago, he started eating less, needing more encouragement to eat, he started having throwing up episodes that I thought was from hairballs, but then this week he stopped eating altogether. Labs and x rays have been normal, no ultrasound due to the expense, he is alert and still moves around although slowly, probably due to age (14). I almost made an appointment to have him euthanized tomorrow because I was fearing renal failure but that's when the labs came back. At the suggestion of somebody, I tried baby food chicken flavor and he is eating it up like crazy. His glucose is off the charts today because he did also nibble on some dry food from my Civvie Molly. The vet wants me to drastically increase the insulin even though he wasn't eating, because he still needs insulin, but I've been reluctant because he's dropped dramatically in the past, but I feel better about increasing the dose now that he's eating again.
The problem is, I don't think he should be eating baby food forever, what do I feed? The vet gave me some cans of the M/D wet food but I haven't tried it yet. He avidly eats the baby food but turns up his nose at his other wet food, so I'm not sure how to proceed at this point.
An interesting point is that he went through the "not eating" illness last year at exactly the same time. He is mostly an indoor cat, but sometimes he goes out under my watchful eye to my fenced in backyard, where he happily munches on grass. Last year I thought his illness was from a flea remedy but that's not the case this year, so I'm starting to wonder if he could be eating something else in the yard that 's making him sick. (I'm in Orlando, FL). Or maybe he is just being incredibly finicky just to torment me.
Any thoughts?
they have actually been sick every time they've stopped eating, so I don't think he is doing this on purpose. 
