Poor little guy! I've got a couple questions, hopefully you have the answers Do you know what type of leopard frog was fed? How long had he been in the pet shop's possession? Has he had any prior medical attention? My first thought is parasites. This is most likely a WC animal. Was he fed live or f/t previously? Most cbb hogs are on f/t for their safety. I, for one, wouldn't trust my adult male to take down a live mouse lol. I would try pedialyte and a f/t mouse soaked in tuna juice.