White patches and unbeatable fin rot?

[SanFranPsychoAquatic]

I’ve been trying to diagnose these problems for 6 months at least. It all started from either zebra danios or guppies from Petco I didn’t quarantine. I suspect the guppies since they have slowly died off, only 3 left now. Some died from bloating, some died from wasting away. Some developed stringy poop and died. One developed a bent spine but took over 4 months to finally pass away.

After seeing very stringy poop, from everyone including the Pleco, I determined it must be internal parasites. I’ve treated with 4 rounds of Levamisole and 4 rounds of Prazipro. Since then, I haven’t seen any stringy poop. Also have not lost any fish since then.

The remaining symptoms are white patches on the zebra danios backs, and white fin rot on the guppies. The patches come and go on the danios, but they never go away. The fin rot does not go away despite very clean water and every bacterial med out there. Danios have almost completely stopped breeding. The small fish in the tank seem to have stopped growing. I’m starting to suspect a mycobacterium infection (aka Fish TB). Pics of the danios below, thanks for any and all advice.

[Kat_Rigel]

As I read through your post, you described doing every single thing I would have recommended. Suspect parasites at first, treated. See patches, treat for bacterial infection (and you did so with multiple medicines.) Aside from adding aquarium salt, I'm not sure what else can be done. I assume you finished the full doses of the antibiotics? Perhaps hitting the fish with all antibiotics at once would be an option, although that is risky because your fish are already weakened and it might put too much strain on their kidneys, etc.

That really sucks. I learned a similar lesson- lost one of my first fish tanks to a particularly fast acting ich outbreak after not quarantining a new platy. By the time I knew what was going on, I only had a few, very weak fish left and they couldn't hang on. I checked with the store and sure enough, they reported that a bunch of their stock had died in the past week too. I now quarantine religiously, 4 weeks usually, 3 weeks minimum. I think all of us have done this at one point.

[Colu]

With the symptoms you describe possible wasting disease I would treat with levamisole once a week for 4 weeks 

Edited June 10 by Colu