Bloated Kuhli Loach! Help?!

[Devi_White]

I went to go clean some of the bigger items in my tank only to find this guy HUGE AND BLOATED! He's got white stuff all over his back and its all bumpy! When I bought him it was at a nearby fish store, and he just looked like a weird looking black(?) kuhli loach, but he had white spots on his back. None of the other fish had it and, despite my better judgement, I took him home. That was probably a month and a half ago, and he's been hiding for the most part so I didn't see how he was doing until today. This hasn't affected any of my other fish that I can tell, but I have no idea what this is or what to do about it! Can someone help me identify what's going on and how I can help this bloated boy?

Picture:
http://i65.tinypic.com/2mphb9f.jpg

55 Gallon
Nitrate 10 ppm
Nitrite 0
Hardness soft
Alkalinity low (20-30ppm)
pH 7
(Using a test strip so numbers won't be exact)

Using a Tetra Whisper 60 filter

Stock:
7 neon tetra
9 guppies
4 black khuli loaches
2 cory catfish
1 amano shrimp
1 bristlenose pleco
(I plan on getting more corys and loaches, don't worry)

I have driftwood, java fern, and water lettuce in the tank as well.
He's still swimming around and I would assume he's still eating since he's still alive after all this time, but he's very sluggish. Doesn't dart around with as much fervor as the other loaches, but I can see why. I've now moved him into my 10 gallon quarantine tank and haven't used any treatments on him yet since I have no idea what I'm trying to treat! Any advice or relevant information would be so much appreciated!

 

[Devi_White]

Old link to the picture seems to be broken.

https://photos.app.goo.gl/v5CMT3Svrxrbi2iv9

 

[V227]

Research Columnaris. It's a bad bacterial disease. Its aka is Saddleback disease.
The loach might have injured his back and the white growth could be a fungus attached to damaged tissue. A situation much better than Columnaris.

 

[Devi_White]

Does that often cause bloating? It would explain the white spots, but I'm not sure. I'm definitely going to read into it more when I get home!

 

[V227]

Let's hope the bloating is due to a hardy appetite and constipation. Bloating is also a symptom of intestinal parasites or a bacterial infection.
Often times, Bacterial infections start internally, and by the time exterior symptoms are noticed, a lot of damage has already been done.