Originally Posted by
Iapetus
It is a male frog, correct? (I can't tell if you're using 'he' as a neutral or masculine sense). It is 'that time of year' so he might have something else on his mind right now. I'm not too versed in frogs, how are you trying to feed him though?
If he's been mistreated for a while, and you recently stepped in and got him the proper things he needed (sounds like his environment changed, correct me if I'm wrong) then he very well may be stressed/nervous about it all, give it some time and he'll come around. I know when I moved my beardie into his new tank he wanted nothing to do with his food for a little while afterwards and just sulked all day.
Wish I could be more helpful, like I said, I don't really know too much about frogs. Hope everything works out!