Floating/bloated Von Rio Tetra

[Corey]

Recently one of my Von Rio (flame) Tetras became extremely bloated and had difficulty swimming, as whenever he wasn't paddling with his fins he would begin to float. He was like this for several weeks, and I didn't think anything was wrong because he would still eat and chase other fish around. I thought he was just fat. But several days ago I noticed him swimming in circles with his head up and appeared to have a cut/sore near the base of one of his pectoral fins. He was clearly in much worse shape than before. He passed away several hours later, I found him laying at the bottom.
Another flame Tetra has also been very bloated for several weeks, but no signs of sores or cuts. In fact, he looks slightly skinner/more normal now. However, he is still slightly bloated and everytime he stops swimming he begins to rise toward the surface; he's constantly fighting to stay near the bottom.
Other inhabitants of the tank include two cories, two Bolivian Rams, a common Pleco and two Neon Tetras. They are all acting completely normal and healthy.
Any ideas as to what could be going on with the Tetras? I was going to buy a few more fish as the tank is understocked at the moment, but am holding out because I'm worried the tank may be diseased. Could it be bloat, or some type of infection? If so, how can I treat it? Is it contagious?

Note: We also lost a Neon Tetra this week, but it didn't show any signs of bloating or distress, and I can't find the body. He may have been eaten and completely unrelated, just thought I should mention it.

Thanks!

 

[TCTFish]

I say it's either bloat or a swim bladder disease. Bloat is when the intestines are blocked (constipation). Try offering thawed out frozen peas. You need to pop the meat of the pea out of it's shell. This acts as a laxative. If it's something else, then You'll need an antibiotic. A QT would be helpful just in case it is a disease and to isolate all the von rio tetras would be advised whether they show signs of illness or not. You've had two with this problem and one died, so all should be put in a QT. Test the main tank water for ammonia, nitrite, nitrate, and pH. Please post results.

What food are you feeding? How much and how often?
How many gallons is the tank?
Type of filter?
How long has the tank been up and running with fish in it?
How long have you had the von rio tetras?

 

[ryan]

the same thing happen to 2 of my neons its still happening to one i fed him peas and he doesnt seem to be getting worst. i got my water tested at my lfs and they said it was ammonia so i got a new filter with 3 step cleaning with ammonia remover in it. but i recommend feeding them peas the test results will also be helpful.

 

[Corey]

Thanks for the replies, guys.
I ended up taking the fishy to a marine biologist at the LFS, and he immediately knew it was an infection of some sort and that the fish had a 99% of dying, and it was risky having it in the tank. I decided to let him put the fish to sleep He examined it afterward - turns out it was teburculosis (sp?), a pretty bad case, you could clearly see it under a microscope.
He told me to wait ~10 days and if the rest of the fish look fine, I could continue to stock the tank.