[AmoAquafish]

I had a quarantine tank of fish come down with what I think to be fish tuberculosis. However it was combined with so many other things (dropsy, pop eye, ich, etc.) that I can't be sure. I separated the fish that didn't seem sick. How long should they stay separate from fish that were never in that tank (hence, healthy) before it is safe to put them together? Assuming of course they don't develop anything. Thanks.

 

[Susan S.]

If you are sure it's indeed a mycobacterium infection, then I would keep them permanently separate. And clean out the tank thoroughly. The first two out of three fish in my first small tank had similar symptoms (wasting away, going away in a corner to hide, dying with severe spinal curvature). The survivor (asymptomatic and in fact still alive, although currently on his last legs from an apparently unrelated problem) was transferred to another larger tank, along with the filter. Since then (eight months ago) I've been losing a fish a month from this tank to this sickness, despite being careful to remove sick fish once they show any symptoms. Now some of the fish in the larger tank had come from the same source as my original fish, so I can't rule out the fact that they also were infected when I got them. But all the recent additions to the tank were from a different source so they have contracted the illness either from asymptomatic fish or by picking it up from the tank itself.

I've decided to not replace any further fatalities and just leave this as a plant tank with a few fish until either they stop dying off or they have all perished and the tank has run fallow for a while.

 

[AmoAquafish]

Does everyone agree? Any other thoughts? If my fish DO in fact have TB all I can say is dang. I read up on fish TB and found out a few things. First it is almost impossible to kill except with bleach. Even if the tank sits dry for a while. It is almost impossible to treat (in the fish). And it can be contracted by humans (not the same as human, respiratory TB). Here is a link on that-- http://www.reefkeeping.com/issues/2003-07/sp/feature/index.php
One thing I wonder about. Susan, the tank that you have continued to have problems with the fish dying is the one the fish originally contracted it in, right? The fish I was wondering about were in tank with fish I think had TB, but they themselves never showed ANY signs of it. They were removed to another tank and have still not showed any signs. Do you think that they carry it? Or do you think it is only the tank? The tank they were originally in was taken down and bleached. Thanks

 

[Susan S.]

No it's the newer (larger) tank where I'm having the deaths. So either the bacteria was carried in the filter media, in my surviving (and still alive!) fish without symptoms, or reintroduced from a newly purchased infected fish. My money is on the last - given the lag of around a month between each death, my best guess is that fish can suffer from the disease with few symptoms for quite a while before they finally show up as sick - then they pass it on.

The original small tank where the first two fish died was cleaned out thoroughly (although not with bleach - I didn't diagnose the issue as mycobacterium until I had the later deaths in the other tank) had the gravel replaced and I haven't had any problems with it (although it now just has a betta in it, and I don't know how susceptible they are - but it's been fine for five months).

The mycobacterium that causes marine fish TB is, I believe, a different one to the one that causes problems in freshwater - most of the human skin infections I've seen reported on the net come from the marine variety.