Is this neon tetra disease?

[Pisces_Girl01]

This bump has been there for about 2-3 weeks...it hasn't grown any bigger yet and fish is still eating normally. It has been in the tank for over 2 years. I think its just a cyst...just wondering if anyone has any thoughts.

[Andy Sager]

No, it's not neon Tetra disease but appears to be just a growth. If it's fuzzy, it would be a fungus which may have been caused by a wound to the mouth. If it's fuzzy and greyish in color, it may be the virus Lymphocystis. Because Neons on the market are mostly tank raised, it's highly possible that it's just a cyst.
Just so you know, this is what Neon Tetra disease would look like: Neon tetra disease - http://i.imgur.com/XMoC09q.png

[Colin_T]

No, it's not neon disease. Andy's picture is a good example of what neon disease looks like. If the neon tetra gets a white patch or mark over the blue and or red line, then it's probably neon disease. The fish usually die within a couple of days of developing this white patch, and it spreads rapidly to other fish in the tank. If left untreated, the disease can kill everything in the tank within 1 week.

The white bump on the nose could be a bruise/ fat lip from swimming into something, however it looks a bit bumpy for that. Fat lips/ bruises usually go away on their own after a couple of weeks.

It is not mouth fungus (Columnaris), which is smooth and spreads rapidly across the face and head and kills the infected fish within 24-48 hours of showing the white lip.

There is a new disease that affects neon tetras. It started showing up a couple of years ago and produces a white bumpy growth on the mouth/ lips. We think it's a virus and there is no cure. The fish continue to swim, eat and act normally while the growth gets bigger. Eventually after several months, the fish starts to have trouble eating and we recommend euthanising the fish at this stage. It seems to only affect neon tetras and appears to be quite new to science. I believe this is what your fish has.