Bloated Frog

[Trollfest]

I had two ADFs and one died yesterday. Last night he was on his back at the bottom of the tank but still moving around sort of but this morning he had died. The other one looks bloated and is floating around on the surface. I looked frog diseases up on the internet but couldn't really find anything out. I put some medication in that contains malachite green but just because I didn't really know what else to do.

Is there anything I can do to save him?