I wanted to relate something from my excellent all-feline vet: "It is strange that he was better with the lower dose than the current dose so there may be some other factors that we can't control for. There are more hormones that increase blood glucose and only insulin which decreases blood glucose. (If he is producing excess of cortisol, growth hormone or has an inflammatory reaction it can make it much harder to regulate with insulin.)" How does one test for excess of cortisol, growth hormone or an inflammatory reaction? I'm going to look into it and will report what I find.