Sick Cory Sterbai

[Andrew H]

Hi all, I could use some help with a sick Cory who was living in my 20g long community tank with 5 other Cory sterbai, 7 rummynose tetra, and an orange flash apisto male. He showed up one day with some damaged fins - he has always been the “odd man out” in that shoal, and is a little bit misshapen. The fins did not heal over time and I started to notice a rough patch on his side. The other thing that is interesting is that he has a rosier color under his gills than the other Cory. I’ve moved him to a small quarantine tank and tried a few treatments. I fed him bloodworms with kanaplex and metroplex bonded for 2 weeks (thesis - fungal infection or bacterial infection). No obvious change. Next I tried a week of formalin / malachite green (rid-ich product, thesis - fungal infection). No obvious change. At this point I’m thinking I just add a catappa leaf and keep the water pristine and hope for improvement, unless someone has another idea. I’ve attached a pic - the brown thread is a bloodworm (he’s still eating enthusiastically). Water parameters are good / stable (0 ammonia, 0 nitrite, 10-20 ppm nitrate, ph 7ish, hardness 150 ppm, temp 78F).

 

[MacZ]

At this point I’m thinking I just add a catappa leaf and keep the water pristine and hope for improvement, unless someone has another idea.

That should be the FIRST thing to do, not the last. Meds, especially antibiotics, are last resort, not first choice.

he has always been the “odd man out” in that shoal, and is a little bit misshapen.

If that fish was a runt to begin with, the chances are high it is immuno-compromised, which also means the treatments were all in vain.
In all the time I bred fish, runts that didn't catch up with the other fish in growth often wouldn't make it to adulthood or died significntly earlier than other fish in the group. I wouldn't invest much effort in treating one if problems like these arose.

I fed him bloodworms with kanaplex and metroplex bonded for 2 weeks (thesis - fungal infection or bacterial infection). No obvious change. Next I tried a week of formalin / malachite green (rid-ich product, thesis - fungal infection).

Only the active ingredient in Kanaplex is indicated for fungal infections, the other stuff is not or just secondarily. Also all three meds put quite some strain on the fish, in case of catfish especially mixtures with formalin and formaldehyde are often doing more damage than anything else in my experience.

Maybe for future cases:
First aid: waterchanges and humic substances
Never medicate on the off chance, and especially not with meds that are not targeting what is suspected. Ask for second opinions before starting any treatments.

 

[Andrew H]

Thanks Mac, that’s helpful. The Cory continues to eat and behave fairly normally, so I’ll remove meds and see how it goes. It’s weird that kanamycin (kanaplex’s sole active ingredient) is indicated for fungal stuff - it’s an antibiotic, not an anti fungal. So that might explain the lack of efficacy (though secondary bacterial infections are associated with fungal infections).

 

[MacZ]

Vendors | BSAVA Library

Appendix III: Proprietary fish medicine vendors Trade name Active ingredients Active against Fresh/marine Manufacturer’s comments API, USA — 0800 014 8173 — www.apifishcare.co.uk Melafix Cajeput oil Bacteria F+M Safe for invertebrates Pond Melafix Cajeput oil Bacteria F Safe for invertebrates...

www.bsavalibrary.com

This list might be helpful as well.

I'm also sceptical it's indicated for it, but the list above is not the only source that names it as anti-fungal. The manufacturer advertises it also as anti-fungal. But as I'm not a friend of Seachem anyways... well.

As I stay clear of antibiotics (which are not available to me anyways), I can't tell you much more.

 

[Eddy. E.]

The problem with kanamycin is that we are talking about an antibiotic for the treatment of eye infections within human medicine. It is used locally and is readily used in fish diseases completely unreflectively. The radius of action is rather limited, due to the low effect against gram-negative bacteria and the far too frequent use.

So before you start shooting at sparrows with cannons, I would suggest you would use herbal therapeutics, which are also less stressful. In Germany, it is much more difficult to have access to medication products, specially when we talk about fish treatment.

When a fungal problem appears, it could have been solved with a simple salt therapy. The myth that corydoras/catfish can not tolerate salt is nonsense. Fungal infections occur as a secondary infection, due to injury to the mucosa. The salt stimulates the fish to produce more mucus, which subsequently causes the mucosal lesion to close and the fungus to disappear. Problem solved. Duration of the procedure at one teaspoon of salt per 5 gallons, usually 3-4 days. In order for the salt to be removed again, an 80% water change is necessary. There is no other way to remove it. All this, of course, without any consequence for the filter cultures. During this treatment, you also raise the temperature to 84F.

To make matters worse, you still use metronidazole in combination, also completely unreflective and as you yourself state, no obvious change. When feeding mosquito larvae or blood worms and to combat possible internal parasites, it would have been sufficient to apply 2-3 drops of garlic essential oil over the food. Completely sufficient. Catappa is of course a great help, but only a help. It supports and prevents. In fact, garlic essential oil achieves up to 40% higher efficacy than metronidazole, e.g. against Spironucleus vortens, only as an example (hole-in-the-head disease).
All, of course, only from the point of view, you have no better expertise. ;-)

 

[Andrew H]

Thanks, Eddy. The good news is that the Cory is still with us. I’ll try the salt treatment - I had indeed avoided it based on hearing cory cannot handle salt.

 

[anewbie]

If you try salt add it very slowly over a several days; also very slowly remove it when you are done. Salt will kill cories if the concentration is very high or the water chemistry change too fast.

 

[Eddy. E.]

Salt will kill cories if the concentration is very high or the water chemistry change too fast.

This is an absolute myth and does not correspond to the facts. It should be clear that you do not put Corydoras in a brackish water broth for treatment. When I talk about salt treatment, we are talking about a heaping teaspoon per 20-25 litres. And that is only dosed once!

 

[anewbie]

Also remember salt does not evaporate; so consider that when doing

This is an absolute myth and does not correspond to the facts. It should be clear that you do not put Corydoras in a brackish water broth for treatment. When I talk about salt treatment, we are talking about a heaping teaspoon per 20-25 litres. And that is only dosed once!

Ok. I should say my cory responded very badly to salt treatment. I used 1 teaspoon per 5 gallons. The cory did not have ick but the borelli with them had ick. Anyway the stuff also killed the plants. So it might be myth but i was just providing my experience.

 

[Eddy. E.]

Ok. I should say my cory responded very badly to salt treatment. I used 1 teaspoon per 5 gallons. The cory did not have ick but the borelli with them had ick. Anyway the stuff also killed the plants. So it might be myth but i was just providing my experience.

So if you used salt and Ick and your Corydoras showed problems, it was not due to the salt, but to the malachite green oxalate contained in the medication. It also contains nitrofurazone. It is highly toxic to humans and, in my humble opinion, does not belong at all in possible medications against fish diseases.
Of course, too much salt in too high concentration, if used for too long, will kill the plants. I always speak of a maximum of 3-4 days for a salt treatment, which is usually quite sufficient, depending upon the problem.

However, if nitrofurazone is also used here, as an antibiotic, a synthetic antibacterial drug that can treat livestock diseases, I see the problems in using it in combination with malachite green oxalate. I am a firm opponent of such fish medicines, as the use pretends to be quick relief and tempts to overuse. It was widely used in livestock and aquaculture a few years ago. The United States, Australia, Canada, Japan, Singapore, the European Union, etc. have explicitly banned the use of such drugs in the food industry and strictly implemented the detection of nitrofuran residues in aquatic products.
Any wastewater treatment plant is likely to experience massive problems with furazolidones and their metabolites.

 

[anewbie]

So if you used salt and Ick and your Corydoras showed problems, it was not due to the salt, but to the malachite green oxalate contained in the medication. It also contains nitrofurazone. It is highly toxic to humans and, in my humble opinion, does not belong at all in possible medications against fish diseases.
Of course, too much salt in too high concentration, if used for too long, will kill the plants. I always speak of a maximum of 3-4 days for a salt treatment, which is usually quite sufficient, depending upon the problem.

However, if nitrofurazone is also used here, as an antibiotic, a synthetic antibacterial drug that can treat livestock diseases, I see the problems in using it in combination with malachite green oxalate. I am a firm opponent of such fish medicines, as the use pretends to be quick relief and tempts to overuse. It was widely used in livestock and aquaculture a few years ago. The United States, Australia, Canada, Japan, Singapore, the European Union, etc. have explicitly banned the use of such drugs in the food industry and strictly implemented the detection of nitrofuran residues in aquatic products.
Any wastewater treatment plant is likely to experience massive problems with furazolidones and their metabolites.

Eddy, I did not say I used medication such as malachite green. I said I used SALT to treat the ick; that was the only thing i used. And yes salt is quite effective at treating ick.

 

[Eddy. E.]

Eddy, I did not say I used medication such as malachite green. I said I used SALT to treat the ick; that was the only thing i used. And yes salt is quite effective at treating ick.

In that case, please excuse me. Then I misunderstood you.

 

[MacZ]

Something got lost in translation here: Ick is what we call Ichthyo or Ichthyophthirius.

 

[anewbie]

I can provide more details: The tank was well established - approx 3 years; when I purchased some fishes i put them in a 120 (i live in a condo and have no room for qt tank but this will be solved next year); that tank suffered mutliple issues due to the new fishes - the ick was a side effect but it cross contaminated two other aquariums which i treated both with salt; one had kuhli and eques loaches with some borelli that got ick the other had some ember tetra and a pair of apisto - the salt cured the ember, borelli and other pair of apisto quite effectively (took around 4 days for the ick itself to vanish); however the kuhli and cory reacted badly as well as the live plants. Anyway that was about 6 months ago - teh salt has been removed and everything is now fine. I cannot say if i put the salt in too quickly or the concentration was too high; but when the 2 of the cory died i made sure to remove it via a daily 10% water change so the removal process was very slow. The remaining 6 cory are doing fine so i presume no long term damage; the group of kuhli were less fortunate.