Tetra Caudal growth/disease.

[finsnthings]

Ok finally got some semi decent photos of my black phantoms.

fish are now in a QT. Have had a full course of Myxazin followed by a full course of Protozin, neither of which even slowed it down. In fact in the last two days the disease has spread on one of the tetras to its dorsal and pelvic fin.

Side on view looking left. Also note some discolouration just underneath the front of the dorsal fin
http://farm3.static.flickr.com/2362/2346728835_be9b1e4b38_o.jpg

Not as bad or vivid in this shot
http://farm3.static.flickr.com/2093/2346728833_193b3da03a_o.jpg

Not the clearest of shots but it really shows just how big the bulge is around the joint.
http://farm3.static.flickr.com/2198/2346728831_9b06d01065_o.jpg

any thoughts?

No other fish in the tank has shown signs. these are the only two black phantoms i have. But they came in a batch of red phantoms 2 months ago.

[Woodsy]

I can't particularly see it very well in those photos, but if it's spreading to your other fish and you can't identify it yourself, see if you can take a live specimen into a large aquarium in your area and ask if they can either identify it for you, or microscope it and identify it that way.
If you've dosed with sterazin (for parasites) and protozin (for protozoa), then the only thing I can really think of is that it could be fungal or bacterial, in which case a course of multicure should do the trick. Problem is that tetras don't like meds, and if you treat them too much in a quick succession they're likely to drop on you.

[finsnthings]

took it to a local yesterday, pretty sure it bacterial.
salt baths and a dose of tetracycline seems to be the order of the day.