Progressing Fin Rot and Now Blisters

[Mutchinator]

Hi - I have a 1,500 G 5 year old outdoor pound; water quality is good - some ammonia but I did water change and that is back. No nitrates etc. I did complete water change in spring and forgot to add salt at that time so my salt was zero as of last week. I have 7 koi - probably in the 15-18” range. It may be pushing size and I am expanding in the spring.

One of my butterfly koi began to develop fin rot on tail and some ulcers after I found a fairly large piece of fin in bottom of pond. He would sit in one spot near the edge rocks away from the other fish. I had some large plastic flower pots upside down with arches cut for koi to hide - I suspect he got some damage when moving in and out of the pots so I removed the pots.

Followed advice on a koi site - anesthesized him with clove oil; and performed some cleanup using peroxide, iodine, denture powder, neosporin and liquid bandage. That was last week - he was getting around great and seemed back to normal activity wise. Eating as normal etc.

Went on vacation but prior I bumped salt to 1,500ppm and had a friend do double dose of metafix daily.

Looked at fish today and some of sores are healing it appeared. Also found another black looking ulcer in another koi.

Removed the initial sick koi today and attached pic. He has some additional rot on pec fins and ulcers are healing it appears but tail still looks bad. I also noticed these small yellow ish bumps on fins primarily. Rather than stress him further I removed a few of bumps with scissors and let him recover and back in pond.

Pic attached - I’m unsure if I should let him alone and see if things cure? Or if I should euthanize him - really prefer not.

Thoughts? Are the bumps koi pox or just healings from an infection or something else? Really don’t want any outbreak.

Did not remove the other fish with one ulcer.

Thanks Jason

 

[MitchM]

Poor guy/gal.
A few questions:
What does your filtration setup consist of?
How close of an eye do you keep on your pond and source water parameters?
Have there been any large swings in PH?
Why do you think there was an increase in the ammonia level? Given it's a 5 year old pond, you should have had a mature enough nitrifying bacterial population established.
Do you use any oxidizers or algaecides?
What is your water change routine - % and frequency?
Where do you live/what is your water temperature?

 

[addy1]

Welcome Jason!

@MitchM is very knowledgeable and will be able to help you. I have only goldfish.

 

[Mutchinator]

Thanks for the reply.
* Filtration - single skimmer; small bog filled with hyacinth and other plants
* I have not been doing a good job of this - but purchased a test kit and will be doing so moving forward. I have well water.
* pH is around 7.8 using pool test kit but I will check again when pond kit arrives. We had a bunch of heavy rains which would have lowered it - so I’m surprised it’s as high as it is.
* Slight ammonia per water test at pond store - negligible per store; but I will test. I did a full water change this spring after cleaning pond. But try to avoid cleaning skimmer/brushes/etc
* I had used hydrogen peroxide to kill string algae earlier this year but only use that on exception.
* I do not have a good change routine but top off as level gets low - probably no more than 10% top off at a time; but 2x per month.
* 77 degF and live in northeast PA

I never had given much thought to doing a better job in managing the pond - but realize that this is a wake up call to do a better job in future.

Thanks again -

 

[Lisak1]

Welcome @Mutchinator ! Sorry to see this guy in such bad shape, but hopefully not too far gone to save.

I think you hit the nail on the head - too many big fish for this size pond. Glad to hear you have an expansion planned in the near future. Your fish will thank you!

We seem to have a rash of "pond salters" lately with fish issues - interesting, as we haven't had much discussion of salt in ponds since I've been a member of the forum.

Stick with @MitchM - he knows pond chemistry.

 

[Mutchinator]

Thanks and yes I have been reading about salting and it’s a lot of mixed signals. Some say .3-.5 for a few weeks and others say no salt. So interested in opinion on that topic. I really don’t want to lose this or any fish - it broke my heart reading about ways to euthanize (clove oil is what I would do followed by freezing if it came down to it). I have a small fish “surgery” setup - and the ulcers I treated last week are definitely healing.

 

[MitchM]

It looks to me like the fish's mucous covering has been stripped away and the skin is now showing the results of suffering from chemical burns. Once those burns open up, the body is more prone to infections and parasites.
The mucous covering can be compromised by poor water conditions.
I think we need to get the fish to rebuild it's mucous covering again. Whether or not it survives depends on it's overall health.
My initial suggestion would be to get the fish into a hospital/quarantine tank, salt free with some melafix.
What water test kits have you ordered so far?

 

[Mmathis]

Hello and welcome. So sorry your fish is sick!

 

[Lisak1]

We can talk salt theory once your issues are resolved... while you're planning your pond expansion.

 

[MitchM]

Your salinity of 1500 ppm is only 0.15% salinity, which isn't too bad. You could transfer the fish with the existing pond water and reduce the salinity by 50% in 24 hours.
I don't think heating the water would be a good idea at this point because heating will also increase bacterial activity and you are reporting that the fish is improving.
Perhaps post a picture of your pond in the meantime.

 

[Mutchinator]

I ordered the API Master Pond kit but didn’t hit submit yet - as price on Amazon went up significantly since last week when I added to my cart. So if there are other options please let me know.

A few questions:
* You mention chemical burns - what type of chemicals are you thinking could have caused this? I did use a Q-Tip to apply peroxide to some of those areas on body which are starting to heal. Also used iodine on those areas.

* The tail rot - what do you feel would cause this? You can see his tail fin is pretty bad. And it seems to have progressed to pec fins since last week.

* I have been dosing entire pond with Melafix - would that be effective as placing him/her in quarantine?

* Somewhat hard to see in pic - are those yellow “blisters” on fins. What do you feel those could be?

* The other fish with what I can see is a single dark ulcer on top of head area - should I leave him be considering the salt and melafix dosing already taking place?

* Should I stop melafix dosing in pond?

Thanks again Jason

 

[MitchM]

My comment about chemical burns was based solely on appearance.
The use of oxidizers or a high ammonia level can burn fish and high nitrate levels can cause blood circulation problems, which could extend to fins.
If you had a log book of past test results saying my water had been stable until "this" happened, then it would be a bit more information to go off of.
It's encouraging to hear that you have minimal filtration and not an elaborate filtration setup involving UV and regular dosages of various oxidizers and algaecides. Algae protects your fish from ammonia. It's also encouraging to hear you are already using melafix, although it's generally a good idea to limit treatments to a separate hospital/quarantine tank because of the lower costs for the amount of medication and in a smaller tank you are easily able to make visual inspections.

Fin rot can be caused by poor water conditions. Since we don't have prior test results, it could be swings in PH, extended low PH, high nitrates or ammonia. We don't know.

I would still suggest transferring the fish to a separate quarantine tank for treatment while you tested the pond water and performed enough water changes to reduce the salinity to zero and flushed the existing melafix out of the system. The present salinity level will be fatal for the plants you have.
If you can, set up a canister filter with some mature filter media on the hospital tank. That's a large fish and will require extra filtration.

Keep an eye on the other fish with an ulcer, he may also need to be medicated separately if his condition worsens.

In addition to the master pond kit, you should also purchase an API KH/GH test kit. Those measurements will help you ensure you have a steady PH going forward. I'm not sure where the best place to buy test kits are in the U.S., maybe someone else can suggest a supplier with lower prices.

The yellow blisters are probably secondary infections, a result of the compromised mucous coat. Have you added any new fish recently?

 

[Mutchinator]

Thanks - I added a bunch of peroxide a few months ago but wonder if a combination of the butterfly koi scraping its tai on the holes I cutout in plastic planters left skin exposed which was then burned by peroxide and then infected. The other fish look ok aside from the other one noted.

* it’s actually much less work (and time and cost as a result) for me to dose melafix in pond versus creating a separate quarantine tank. Do you feel it is acceptable to treat the entire pond as I have been with melafix and if so how long?
* sounds like I need to gradually ramp down salinity to zero in pond? Assuming that massive water change would stress and harm fish?
* think I should check for parasites (microscope) and any chance the blisters could be pox or ich?

I am time constrained due to job and kids - so trying to find the most efficient (not necessarily lowest cost) approach within reason.

Really appreciate the help so far - Jason

 

[MitchM]

I think if you can keep up the required daily dose of melafix, and you're willing to replace any plants that may not make it through the salinity, it's workable. Minimum period for daily dosing of melafix is 7 days. Reassess and continue treatment if necessary.
Good water quality is the most important factor though. Without that, any sucessful treatments won't last.
I can't stress enough the importance of knowing the water test parameters.

 

[Mutchinator]

Most of my plants that are dying are seasonable hyacinth - other plants I removed prior.

So I will keep dosing melafix and keep eye on things. Should I change salt levels at this time either up or down?

And any chance this is parasites or virus?

Thanks again. Will post test results once I have kits this week.