Deformed Tetra, Should I Euthanize?

[zupeer]

one of my glowlight tetras is becoming a bit strange. over the past 2 months, he's gotten skinner with his stomach caving in and his spine formed a slanted "s" shape, and at one point he had a small white patch on his head. the patch went away within a couple of days but he remained skinny and extremely malnourished looking, but I feed my fish plenty of food and a good mixture. He had a few white patches along the top of his body a few days ago but it looks like they're gone but I'm not sure, I can't see too well in the QT container he's currently in.  despite all of this, he's been active and eating plenty and none of the other fish display this. I've been giving him daily salt baths to see if this helps and he's just hanging out in the small QT. 
Anyways just from the description, is this possibly nbd? I've looked at pictures and he doesn't look at all like them but he has the curved spine and the weird white patches. I haven't seen anything though that would explain his caved in stomach... Plus I read that they die within like a few days though of having it but he's been here for over 2 months, so I'm at a lost. From what I read online, it's best to euthanize fish with nbd for their own sake but I would hate to have misdiagnosis him since he's still very active and going strong. I thought it was old age at first since I don't know how old they are (they were passed along from 2 aquariums before mine) but now I'm not sure. I don't know what's best for him at this point... I'd like to put him back with the others but I don't want to risk any disease spreading if it hasn't already.
my water parameters are 0 ammonia, 0 nitrite, 10 nitrate. they're in a 20 gallon with heater, 2 filters, and plants.
Here's the best picture I could get. Any ideas?
 

 

[Chad]

Before I euthanized it I would put it in a separate tank or container and feed it there for a while. While there is more than one cause for symptoms like this malnutrition is a common one. Feeding it by itself makes sure it gets enough food, doesn't get picked on while gaining strength, and allows you to give it a specialized diet higher in calories and protein than the other fish. I recommend daphnia, and fry food as a supplement to what you normally feed.

 

[zupeer]

I can't make a run to the store any time soon (Extremely busy this week and store is a bit far) so would giving him a mixture of shrimp pellets, flake food and maybe a wafer be okay? He's used to eating from the bottom since the bigger fish would dominate the top so he's used to being fed only the pellets which he loves. is there any veggies you would recommend too? 

 

[Blondielovesfish]

You could try some mashed up,thawed deshelled peas.

 

[Chad]

Flake, and the shrimp pellets slightly crushed would likely be good. The main thing is that his in a container of his own. That can be something that hangs on the side like a breeder net or plastic container with a lid that can sit in the tank. As long as there is flow through it somehow.
 
Like this...

...this...

 
...or this...

 

[zupeer]

Well I have him in his own separate container with heater and filter since I first thought it was NTD and didn't want it spreading. Plus it's a lot more comfy than the breeders net I have, and he seems to be fine in the QT. One thing that concerns me is he's spending time at the bottom which he has never done before I moved him, so he only accepts pellets. I'll try some peas tomorrow though during his salt bath

 

[bristlenoseitplecoman]

don't euthanize him. I accidentaly bought a tetra missing half of his tailfin. he still puts up a good fight with the other tetras. my guess might be old age but it could be anything. age makes them more susceptible to disease.

 

[TallTree01]

One of my neon tetras when I bought it didn't have a tail!
I swiftly seperate it and it grew back. Don't euthanize the tetra, just keep him alone and see how he goes.

 

[zupeer]

Well isolation didn't help too much... He was extremely depressed looking and pretty much stayed on the bottom the whole time, and it was very hard feeding him since he couldn't really find the pellets. I moved him back to the main tank in the breeders net and I was able to see that the white patches got worse. They are fuzzy but not ich... They're only on his body too and he doesn't look different from before. He's a lot more active now that I moved him back, and he acts like all the others but he looks awful... I can't get a picture of them because they're very hard to see, but what do  I do? I've been giving him salt baths once a day but I've seen no improvement.
I will most likely euthanize if there isn't any other option. It literally looks like he's wasting away and I don't know if it's more cruel to keep him alive at this point.

 

[techen]

White fuzzy spots on him could be fungus? I mean that would explain him sitting at the bottom.

 

[zupeer]

He didn't sit at the bottom before I moved him into the QT. I  was thinking it could be fungus too but would that affect his spine and caved in stomach?

 

[snazy]

Bacterial infection(caved stomack), possibly accompanied by fungus as a secondary disease.
Get some meds for him, put him back in the quarantine tank and treat him. He may recover.

 

[zupeer]

Okay which do you recommend? 

 

[greenmumma141]

I would go with an anti fungal. API meds are usually good and readily available here in the states. Once you get the fungus under control, I bet you'll see a big difference. You'd be amazed at the deformities that fish can live with

 

[zupeer]

Thank you very much, I'll set the QT tank up again and stop at the store either tomorrow or this weekend. Hopefully he can hang in there for a bit longer. Just curious though but is this similar to ich in that if one fish is infected, the whole tank needs to be treated?