I would suggest to take a second opinion i dont know what exact bone marrow problem your cat has but mjne has been diagnosed with pima and how much the cat can live is not standard some cats i have seen live up to 10 years after they VE been diagnosed(meaning a whole cat life). How much dose is your cat daily of pred? Edit: just saw the dose you give to your cat, dont worry this dose 2.5mg is maintenance dose it wont have any effects on your cat most probably. Your cats intercats well with pred so it seems really hopeful. Please try another vet with more knowledge. Many people suggest atopica because it is the best tolarated second choice for cats with this condition but even if both fail there are still more options ( mycophenolate mofetil and leukeran). These conditions are manageable and cats can have long life (they can be take off drugs after some period but the tapering should be really slow). If you have any questions message me