I think my African Clawed frog has bloating disease, help!

[IrrekEkcif]

My brother has had this frog for 21 years, and since he moved out I started to take care of him. He's an African clawed frog, (not dwarf). My brother took terrible care of him and almost never changed the water and also fed him every day. I read online that these types of frogs are only supposed to be fed 2-3 times a day. My brother fed him reptomin. Kermit is very bloated in his stomach, but not so much in his chin or legs area. He doesn't float on top and seems to be swimming just fine. If anything he looks like he struggles a little to the top to get air because he's so bloated. I put Kermit into a new tank with clean, conditioned water now. But I'm not sure if he is bloated from being overfed or because of the poor conditions of the water he was living in before. I'm not sure what to do and how to treat this. Here's a picture of him.

[SanderB]

Maybe he swallowed the black grind on the bottom? 21 years, that´s old, the oldest I have ever seen, I had 1 that was 10 years.

[rodsboys]

You really shouldn't use that small gravel for an animal that is such an aggresive eater. That fact that the legs are not bloated is a good sign. As far as I know the legs usually bloat too on these frogs when they have bloat. Perhaps he is impacted from swallowing the gravel? How long has he been like this?