What's wrong with this poor thing?

cmb19

I have zero hope that this fish will survive, I've had it for a little over 2 years now and in the past couple months it got extremely skinny then ended up going back to normal size and a few weeks later ended up with a tumor type bump. One side of the fish was a larger bump than the other side, but had no problems with eating or swimming or anything so I let it go. This morning I got up and the tumor looks like it exploded inside the fish. There's no blood or anything coming out of the fish, just looks like it's bleeding internally inside.

I'll post some pictures just because I'm curious what has happened to it. It's a Zebra Danio, I only have 3 zebra danios in the tank, no other fish and there hasn't been anything other fish for very close to a year now. Please don't judge me on the algae in the tank, I've been having issues with it for quite some time now, it will go away and come back in a few weeks. The only way I could get semi-clear photos is when it stopped swimming and sat on the bottom, otherwise the fish can and will swim almost entirely normally.

It is actually much redder than in the photo.

cmb19

I more carefully have read through the sticky about fish diseases....I completely forgot that this fish and one of the other 3 danios I have in the tank have gone through a period where they had a crooked spine, which eventually went straight again. Well, I noticed fish tuberculosis this time through the list and now I'm worried that could be what's going on. Just how contagious is this for people? I've had my hands in the tank more than I can count since my fish "went crooked." Last spring I was hospitalized for several months and nearly died so was unable to take care of the tank. My aunt cleaned the tank and got rid of an algae problem that I had then and she didn't get sick either, even though one of the fish was crooked. Since we both cleaned this tank and didn't have any issues, does this actually rule out fish tuberculosis or am I worrying about this more than necessary?
If this is what's going on, then I'm going to euthanize and seriously disinfect this tank.

Romad

No clue as I have no experience with that. Google as much as you can. I hope nothing bad comes of it (other than the poor fishy that is).