Dying Pygmy Corydoras

[Neha]

*DISCLAIMER: DEAD FISH PICTURE*

Water Parameters

pH-8, Nitrates-0, Hardness-10, Nitrite-0, Ammonia-0-0.25, Kh/Buffer-10, Temp-78F

These are the parameters of the hospital tank. Unfortunately I had to wash my emergency filter bcz I was keeping rescue fishes (I didn't want any diseases traveling). Their main tank (10g) has the same parameters except it is cycled and has a betta fish (Frodo). Frodo has been very polite and I have never seen aggression or chasing. He sometimes does hog most of the food but other than that he just observes them swimming around.

I got 12 Pygmy Cories on Dec 22 and set up a cycled quarantined tank (I keep a spare filter in the main tank). I did not put any medication but asked the store and they said that they had dewormed them. I observed them for two weeks, they looked good, so I transferred them to the main tank. After this I saw some flashing and asked some people but they said it wasn't a big deal. Fast forward Feb5th, I see one of them literally dying (he tried to wedge himself between the substrate and a crypt root. I took him out, tried to give him some food but he died within the next few minutes. I try to observe the tank more closely and I find two more fish laying kinda still and not moving around much. The next day another died (he too wedged himself between roots). I take them all out and set up a quarantine tank. The third wasn't looking good (pale and very lethargic). He died the next day.

All the fish that died did not have any visible injuries, signs of any external infection, nor any funky poop. I decided it is probably internal parasites and do a round of API general cure (cz I didn't have anything else). I had to change the water earlier than recommended because ammonia was rising.

Current situation:

There is one fish that doesn't look very good to me. He lays still and goes up for air quite often. I observed him today not eating a lot of food while the others were going nuts on brine shrimp. I don't see any visible infection signs or anything on him. I have paracleanse now, I also have API general cure. I am out of my wits trying to figure this out. I have no idea what's going on. Do let me know what you think and what you would suggest I do in this situation. Do I do another round of API general cure after 2 weeks since the first round? Or should I try paracleanse? Or something else? 

[Torrey]

I'm going to tag @Colu for medication knowledge. 

Have you increased the dissolved available oxygen with extra aeration?

Because it sounds like (and I could be wrong) something stressed first cory, it tried to hide and probably emitted a stress hormone which other cories would be sensitive to. 

Plus, at pH of 8, **any** ammonia is going to be highly toxic to cories. They are more sensitive than many fish.

So there's ammonia that is present, which can trigger cories to release their own toxin/venom, which they are also sensitive to, and that is a recipe for a rapid downward spiral. If there is also low oxygen, that's causing issues. 

Multiple water changes throughout the day, minimize feeding as the filter catches up (immediately suction out any food they don't finish), and as far as meds go, follow Colu's directions. 

[Neha]

I do have a sponge filter going in the hospital tank. I do water change every day but I will increase their frequency.

what I don’t understand is the first two cories died in the main tank, which has no ammonia. The third was very sick in the main tank and died within half a day of putting in the hospital tank. None have actually gotten sick in the hospital tank and died.

[Colu]

What your describing I would do a combined treatment of fritz Expel p as that requires 1 dose leave 24 hr then water change repeat in 1 week for a total of 3 weeks  and I would also do a course of kanaplex in food  feeding a small amount twice a day for 1 week that will cover all base as it could be internal parasites or an internal bacterial infections  paracleanse and general cure have the same active ingredient praziquantel and metronidazole they are better for treating flukes and tape worms Expel p active ingredient is levamisole is a more powerful 

Edited February 21, 2022 by Colu

[Neha]

So do I start the Expel p and the Kanaplex dose simultaneously?

[Colu]

On 2/21/2022 at 7:06 PM, Neha said:

So do I start the Expel p and the Kanaplex dose simultaneously?

I would do one dose of Expel leave 24hr water change and then start treating.with kanaplex you can use them both at the same time if you add kanaplex to their food

[Neha]

I usually feed them frozen brine shrimp and repashy community plus. Can I mix kanaplex in the repashy mix while setting it (without the focus thing)? Thanks a lot for your advice, really appreciate it.

[Colu]

You don't have to use focus but it does bind more of the medication to the food

[Torrey]

Thank you Colu.

What I am able to do for newborns and birth parents, you do for fish.

[Neha]

On 2/21/2022 at 12:31 PM, Colu said:

I would do one dose of Expel leave 24hr water change and then start treating.with kanaplex you can use them both at the same time if you add kanaplex to their food

Thank you so much. I know this is a late reply but I wanted to give an update on this. So I followed what you said and I used frozen food for kanaplex. There was one more corydora that died after I started the treatment. He just sort of vanished, I'm assuming that he died and the others ate them? However, after that I did not see any deaths and kept them in quarantine for a few more weeks after the treatment. Fed them tons of repashy and brine shrimp. They are now in the 15 gallon community tank and I haven't seen any casualties since then. I'm assuming that it was some sort of internal parasite or bacteria because that looks like the only possible explanation.

Lesson learned: Quarantine your fish with med trio always.