my uncle's sick fish
My uncle has had his zebra danios for forever. He used to have 3 and now he only has 2. My mom is taking care of them while he is out of town. Yesterday, she asked me to come take a look at them because she thought something was wrong. One of them was actively eating but had a huge bubble looking thing coming out of his side, the other was laying at the bottom and would only move if one of the cory's ran into him. He is extremely emaciated looking and his spine is curved into an "s" shape.
Like I said, my uncle has had this fish for many, many years (10+ probably), so I don't think he will be surprised that they are ill, but the one staying at the bottom, does it sound like fish tuberculosis? I don't think my uncle has a quarantine tank, but he does have other fish in there in addition to the other danio. He has 3 red live bearing fish, 1 male and 2 female. The females are very pregnant (I know, the young will get eaten) and the 2 cory's, and maybe a sucker fish. Are all his fish going to get it? What do I tell him? He's supposed to be back today.