>>1981507If it ate an apple out of your hand, it probably doesn't need a formula mix at all. Post a picture and I can tell you what kind of diet is best.
However, if a cat was playing with it, then it needs to go to a rehab. It very likely has internal injuries. If it has an puncture wounds from the cat, no matter how small, they will become infected and kill the possum.
Again, just take it to a rehab, where they have the proper materials to care for it.
