I read it takes about 5 days for you to see the full effects of prednisolone when starting, so about a week for a decreased dosage makes sense. From the anecdotes I've come across online it's a quite common practice to start off high and then adjust down, so your vet probably won't be surprised at all to get a call inquiring about ravenous appetite and should I adjust.
Okay, good to know what others have dealt with. I didn't realize that even the low dosages can cause such increased hunger. Thanks for the info and links. Since we do have an appointment this Friday and we'll have a full blood panel done, I'm going to wait and see what the results are before spending money on a blood glucose monitor.
I wrote my update on Saturday I think, and Sunday he didn't seem to be as ravenous. Of course.In fact, both Sunday night and this morning he didn't finish all his wet food right away like he normally does. And I think there were less "pee pods" in the litter box. Maybe it takes a week for the body to fully adjust to the decreased dosage of pred?Otherwise, I suspect he might have a tummy ache or a soon-to-be hairball.
For the blood sugar test, keep in mind that cats have stress induced blood sugar levels. All my vets (except for one that I deemed incompetent) told me testing out of range but in the 200's probably indicates stress. They said that testing in the 300's or 400's was more likely diabetes.