Ok, so if im correct in your trouble in the enclosure answers you say you have owned your frog for about 6 months. And if u haven't changed your substrate since you got him then I would say that could be playing a big part. Im no pro but if you have him in 5 gallon tank that's not very big and even though you pick up his poo his pee is in the substrate. So if im right with the first part, by now he is sitting in his own urine. I would change his substrate ASAP, that is way to long. He may have contracted a bacterial infection or something.