he looks in decent shape. thats good. mice are too small for him though. deafinitly could be on a small-medium rat. ill lean more to medium.

did i read right? did he/she in fact regurge? if so you should skip feeding for 14 days. as the stomach acids realy thrash there throat and mouth fro ma regurge and there stomach flora will be low and it needs time to replenish.