I'll ask Ann to drop in. Megan's had SRMA several times now, and each time Ann catches it sooner - and it's treated quickly and Megan recovers fast. Side effects of pred and Aza can be an issue so you must keep an eye out for that.
SRMA is very treatable - it's one of the most treatable AI diseases. Make sure you get a gastroprotectant from North Downs, as well as the high dose pred - and are they putting him in Azathioprine too - or just pred ? have they given him in injection of dexamethasone ?
Any help you need, just pm me - you are more than welcome to join CIMDA support if you want to (my online AI support group been going for 7 yrs now).
Try not to worry too much, SRMA really is one of the "better" AI diseases to get. Unfortunately we seem to be seeing a lot of springers getting it nowadays.