Red bloody patches on cory

[KTpoopenstein]

Yesterday I noticed one of my peppered cories didn't look too hot. No noticeable infirmity, but he wasn't swimming, and I wasn't entirely sure he was actually still alive until I went to fish him out and he darted away. Figured maybe he was sleeping or something so I didn't think too much of it. I checked my water parameters just to be safe, and everything was fine: ammonia, nitrate & nitrite all undetectable, pH 8 (which is normal for my tank). This evening I happened to look in my tank and saw that one of my cories had red patches down both sides and he was on his side sort of twitching. Not good obviously. Went to get my phone to snap a picture and when I came back he'd moved, and was twitching on top of my other cory, who I'm 99.9% sure is dead.

I can't net a fish out without draining some water (my arm will displace too much water and it overflows...found that out the hard way!) so I pulled out my siphon and started sucking up some java moss debris I'd been meaning to clean up and managed to suck up both sick/dead cories, so I moved them to my quarantine tank. Sick guy is still twitching, and the other guy doesn't appear to have moved so I'll flush him momentarily, but I was hoping someone could clue me into what's wrong with my other guy.

Of course this would happen the night before I go out of town for a few days, and after every store around here that I might get meds from has closed for the night.

Some background info on the tank: 15g column, planted.
Inhabitants: 8 neon tetras, 1 serpae tetra, 2 nerite snails, (now) 1 cory and a couple dozen red cherry shrimp. I know my tank is too small for the cories, but I have them and I don't have anywhere to rehome them so it is what it is. I have tetracycline and pimafix on hand, along with a variety of old ick meds, but that's about it. Anything that I can do before I leave tomorrow? I might be able to get something before I leave, but I'll have to rely on family to do the dosing for the weekend...

 

[KTpoopenstein]

So the guy I thought was dead apparently is still alive, but it's probably not a good sign that I thought he was dead and sucked him up in the siphon...he's just kinda sitting there unless I nudge him with something.

They're in a 2g tank with a little filter right now.

 

[GreenLily]

It looks like red blotch disease. This happens a lot with corydoras who are living with poor water quality, but you have stated that the levels are fine. Another possibility is that the barbels have eroded because of the gravel, and that could in turn, cause a bacterial infection (red blotch disease). I'm not too knowledgeable on how to go about treating it, besides doing multiple water changes and definitely switching to a sandy substrate.
Can you see if he has his barbels still or not? He seems to be in pretty bad shape, so I'm not sure if there is much you can do with him except put him out of his pain.

 

[KTpoopenstein]

Barbels are fine. I looked at the tetracycline I have and one of the things it supposedly treats is hemorrhagic septicemia which it describes as bloody streaks on the body...so I'm giving that a try. I've instructed my parents on how to continue treating while I'm gone so we'll see if he's still kicking when I return!

 

[GreenLily]

Hopefully it helps him! Keep us posted, please!

 

[KTpoopenstein]

Well that was quick. The one with the bloody sides is dead. The other one still responds when I nudge him but he's been in the same spot for the last few hours.

 

[KTpoopenstein]

I am sad to report that the Cory that was still hanging on when I left has finally left the land of the living. He was still alive when I got home yesterday but was on his side and not moving much (I could see him breathing still) and he may have had a bloody patch on his tail but I'm not 100% sure, but by morning he was dead. Not sure what happened. Everyone else in my tank is active as normal and looks happy and healthy, including my other Cory that I've had longer than the two that just died. She's actually my oldest fish at this point, and still going strong!