Fire Belly toad being very sluggish, not eating, skinny, second time I'm asking-HELP PLEASE!?

My fire belly toad, Spud, has been extremely weak and sluggish and will barely move in a full day. When I tap on his back to try to get him to move, he hops, but its not a normal hop, its like his leg is also injured and he sometimes flips over while hopping. Most of the time when he is still, his head is on the ground and he looks like he's dead basiclly. His tankmate is absolutoly the opposite. I even try handfeeding him, no response. PLease help or I think this is the end to spud. Even if it is, I would like to know how he dies, what sickness this is, and how it is prevented.Again, the second time im asking, no response from any of you! >:(