Re: BG very high at AMPS pls help
For my cat, Mona, she consistently had BG levels in the 400s when eating dry food and then they dropped to under 100 when she was on wet food alone. Just a little bit of dry food could be keeping your cat that high, too, even with a pretty large dose of insulin. But, it could be several of the other things mentioned, too. It's never just one factor that controls the BG numbers.
I hope he feels better all-around soon and that you can find a wet food that he does well on.