Oh, no!
Does your fish have discolored white patches on his scales?
It might just be columnaris.
Today, I am going to teach you everything you need to know about columnaris – including how to identify and treat it.
This guide might just save the life of your fish.
Contents
- What is columnaris?
- How does columnaris get inside your aquarium?
- How do you identify columnaris? (symptoms)
- How do you treat columnaris?
- How do you prevent columnaris?
What is columnaris?
There is a lot of misinformation about this disease, even on sites like Wikipedia. So, let’s straighten some of this out.
Bacteria causes columnaris – Flavobacterium columnare to be exact. Don’t worry, no need to remember this name! Everyone in fishkeeping either refers to it as columnaris or, less commonly, Saddleback disease.
Columnaris bacteria are small. Real small. So small that you need a microscope to see them. Here is the gill of a rainbow trout infected with columnaris…
As you see, when viewed under a microscope, the bacteria resemble rods or columns– yep, that’s how this bacteria got its name.
Columnaris only affects freshwater fish, both in the wild and in aquariums. It cannot live in salt water.[1]
Any species of freshwater fish can come down with a columnaris infection.
Columnaris is very dangerous and will kill your fish if left untreated.
In fact, a columnaris infection can kill your fish rapidly – sometimes it only takes a day or two from the first sign.
If your fish’s symptoms match that of columnaris, then you need to start treatment right away.
Columnaris is also very contagious between fish. If one comes down with it, then all the other fish in your tank are also at risk.
Fortunately, humans are not affected by columnaris. You and your family will not get sick from an infected fish.
How does columnaris get inside your aquarium?
Here’s the interesting thing about columnaris:
It’s already inside your aquarium!
Yep, it’s just hanging around, waiting to strike. In fact, columnaris exists in every freshwater aquatic system – everything from small betta tanks to large-scale commercial operations have columnaris in the water.
In fact, columnaris is a huge concern for commercial fisheries since it is highly contagious and can wipe out large numbers of fish very quickly.[2]
However, as explained later in this guide, even though columnaris is present in every aquarium, it is only a threat to your fish in very specific, and preventable, circumstances.
How do you identify columnaris? (Symptoms)
Columnaris is quite difficult to identify and is often confused with fungal diseases such as cotton wool disease or cotton mouth disease. Straight up, if you see little tufts of cottony stuff that resemble white-colored bread mold, it isn’t columnaris.
What makes columnaris so darn hard to identify is that its appearance varies dramatically according to how far along the disease is. To add to the confusion, different strains look and act differently from each other.
To keep things simple, Columnaris strains generally fall into one of two categories, fast or slow. The fast columnaris can kill your fish within 24 hours. In most cases, your fish will be dead long before you even notice any symptoms.
If your fish is still alive and shows the following symptoms, then you are dealing with a slow strain of columnaris – it’s still deadly, but you should be able to treat it if you catch it quickly.
Generally, columnaris starts out looking like bleached or off-color patches on the body of your fish. As the infection grows, the surrounding scales also begin to look washed out.
The exact color of the infection varies based on the color of your fish and how far along the disease is. While it’s most commonly identified when white, it can also look yellow or even orange.
It’s important to note that these discolored patches will be flat – not bumpy or fluffy.
As the infection continues, it can completely eat away at the scales and skin of your fish. At this point, the skin splits, and the scales turn white and flake off. The disease can also form long filaments that are visible to the naked eye. It’s this stage where the columnaris disease is usually misidentified as a fungus.
As the bacteria continues to eat through the skin of your fish, it reveals the muscles underneath, looking bright red and bloody. If left untreated, columnaris will eat a hole in your fish.
This can happen anywhere on the body of your fish…
Less commonly, the infection shows up as a distinctive round patch behind the dorsal fin of your fish. It kind of looks like your fish is wearing a small horse saddle – this is why you sometimes hear columnaris referred to as Saddleback disease.
Columnaris can also start as a mouth infection.
When this happens, your fish’s mouth looks bleached, like it’s wearing lipstick.
As the mouth infection continues, the columnaris eats away at the skin inside and outside the mouth, causing it to flake and become puffy. This is often misidentified as a mouth fungus when it’s actually columnaris.
Columnaris can also take a foothold in the gills, making them look bloody as it eats away on the inside.
Unfortunately, columnaris of the gills is almost impossible to identify while the fish is inside your tank. Most people only recognize columnaris of the gills after their fish dies. Instead, you need to look for other symptoms that provide clues to look closer at the gills of your fish…
As columnaris eats away at your fish’s gills, breathing becomes more difficult. As a result, your fish’s gills will move much faster than normal as he tries harder to breathe.
You may even notice your fish move to the top of your tank where there is more oxygen or even gasp for air at the surface of the tank.
Fish suffering from columnaris are often less active and may not eat well or refuse to eat altogether. It’s worth mentioning that lack of energy and refusing to eat are common symptoms of many aquarium diseases and, on their own, do not mean that your fish has columnaris.
Scratching is the final clue that your fish has a columnaris infection – columnaris can be itchy. Since your fish doesn’t have hands, he will swim close to objects and brush against them in an effort to make the itching stop. This can result in scrapes and worn down skin, exposing muscle and flesh.
As the columnaris progresses, you may notice that your fish’s fins look bleached out, ragged or even completely worn away. This is commonly referred to as fin rot.
Not all fish with columnaris develop fin rot. In many cases, it’s a secondary infection, which brings me to my next point…
Your fish can catch more than one disease at a time. In fact, by coming down with columnaris, your fish is actually more likely to be afflicted with another disease.[3]
Because your fish is already weak from both stress and columnaris, your fish is more likely to catch other diseases than he normally would.
For example, this platy is suffering from both columnaris and Ich…
A second disease caught after the first is referred to as a secondary infection.
This is why identifying any fish disease can be difficult – your fish may actually be battling two diseases at the same time while you are trying to determine a single disease.
While any aquarium fish can come down with columnaris, certain fish are more prone to it. This is a particular problem with fish bred in huge numbers, such as betta, with weak genetics. Livebearers like guppies, Endlers and platies are prone to columnaris as well.
How do you treat columnaris?
Have you diagnosed your fish with columnaris?
Well, the next step is getting rid of it.
Incorrectly treating columnaris can harm or even kill your fish. That’s the opposite of what we are going for, right? So, carefully read each step before taking action!
Step 1. Quarantine
Ideally, you want to place any fish showing symptoms of columnaris into a separate hospital tank.
This helps in several ways:
The most obvious advantage of a hospital tank is that it prevents the columnaris infection from spreading to other fish.
Second, it stops your sick fish from being bullied by healthy tank mates. For their own safety, healthy fish often instinctively drive off a sick fish. In an aquarium, however, the sick fish has nowhere to go, and this bullying will only stress the fish out further.
Next, medicine is dosed according to the amount of water in your tank. If your hospital tank is smaller than your main aquarium, then you won’t need as much medication. Medicine can be expensive and treating a 10-gallon hospital tank versus a 30-gallon one can result in big savings.
Finally, medication can stress healthy fish. Some can even kill the beneficial bacteria inside your filter. As a result, only use treatments when dealing with a harsh disease like columnaris. By only treating your sick fish, your remaining fish won’t be exposed to heavy medications.
Step 2. Check your water quality
As with any disease, to see the best results when fighting columnaris, you want the water in your tank to be pristine.
You should already be regularly testing your water with a good aquarium test kit. If you aren’t, now is the perfect time to start.
So, grab a test kit and check the following:
Not only will good water quality allow your fish to recover faster, but it can also impact how certain columnaris medications affect your fish.[4]
If anything looks out of the ordinary, fix it before moving forward with the columnaris treatment.
Step 3. Turn down the heat
Columnaris loves the heat.[5] The warmer the water, the faster columnaris spreads.
Ideally, you don’t want the temperature to exceed 75°F (23.9°C). If your temperature exceeds 75˚F, then you want to decrease it to slow down the spread of columnaris – doing so gives your fish the greatest chance of survival.
Now, the trick to lowering the water temperature is to do it slooooooooowly.
You see, fish are sensitive to rapid changes in temperature. If you lower it too quickly, you risk killing your fish. For more info, check out our guide to aquarium temperature.
So, instead of adjusting the water to the lowest temperature your fish will tolerate, decrease it by 2˚F (1˚C) every hour until you reach the desired temperature.
When doing this, regularly test the temperature with a good aquarium thermometer to make sure it is still in your fish’s comfort zone.
It’s important that you only adjust it to a temperature that is as low as they will tolerate. Research to find the preferred temperature for your fish. Those with community tanks, meaning with multiple types of fish, need to find the sweet spot where they are all comfortable.
Step 4. Dose your columnaris medicine
Many expert fish keepers recommend a combination of nitrofurazone and kanamycin as the best treatment for an outbreak of columnaris. And, I agree. I have used this treatment on more than one occasion to successfully cure my fish of columnaris.
In my opinion, this treatment gives your fish the best chance of survival. Using one or the other does not seem to have the same success rate – so use them together.
First, you need to grab medicine with nitrofurazone as the active ingredient. I personally use this one…
| Contains | 10 packets |
| Dose | 1 packet per 10 gallons |
| Full course | 4 doses |
Next, you need a medication that contains kanamycin as the active ingredient. I personally use this one…
| Contains | 27 scoops |
| Dose | 1 scoop per 5 gallons |
| Full course | 3 doses |
Have these two medications? Now, it’s time to dose your fish.
Here is how I dose the two for maximum effectiveness. Add a single dose of medication according to the following schedule, I add an extra course of Furan-2 on day 5.
- Day 1: Furan-2 and KanaPlex
- Day 2: Furan-2
- Day 3: 25% water change, Furan-2 and KanaPlex
- Day 4: Furan-2
- Day 5: 25% water change, Furan-2 and KanaPlex
It is worth mentioning that in severe cases, you may need to do back-to-back treatments on your fish, for a total of 10 days. This is a judgment call that only you can make, based on how well your fish has recovered.
This powerful 1-2 punch of medication should be all you need to beat columnaris for good.
How do you prevent columnaris?
Most people believe that columnaris bacteria exist in every aquarium.
So if that’s the case, then why doesn’t every fish become infected?
Well, columnaris often strikes when a fish is stressed and in a weakened state – when your fish’s immune system cannot fight off the disease.
So if you eliminate stress, you make your aquarium columnaris-proof, right?
As if you needed another reason to stop stress, it’s the number one cause of death in fish.
Fortunately, keeping your aquarium stress-free is darn simple. In fact, much of it comes down to good housekeeping – things you should already be doing!
- Cycling your aquarium
- Quarantining new fish before adding them to your tank
- Not overstocking your tank
- Stocking compatible fish and invertebrates
- Testing your water quality
- Keeping water parameters stable
- Cleaning and maintaining your aquarium
- Performing water changes
- Not overfeeding your fish (and feeding a balanced diet)
Not too hard, right? These simple tasks keep your fish happy, healthy and safe from most aquarium diseases.
For those of you with hard water, there is one additional step you can take to prevent columnaris…
Reduce the general hardness (GH) of your aquarium.
Several studies show that reducing the GH of your water makes it harder for fish to develop a columnaris infection.[6] [7]
To put it simply, the theory is that bacteria cannot attach themselves to fish effectively in less hard water.
For more information, check out our GH guide. It covers everything you need to know about the importance of GH and how to balance it.
Conclusion
As you see, columnaris is one of the nastier aquarium diseases.
But if you catch it early and with proper treatment (and a bit of luck), your fish will beat columnaris for good.
A sad fact of columnaris is that even if you do everything correctly, your fish still might not make it – perhaps you caught it too late, or it’s a fast strain.
If your fish doesn’t make it, don’t beat yourself up. Go through our preventative steps so that you don’t face the same problem in the future.
I would also add that if it’s too late for treatment, you may have no other solution than to euthanize your fish. I know it can be hard, but it may be the only way to stop your fish from suffering.
How do you treat a columnaris infestation? Let me know in the comments below!
I also use this site as an excuse to spend lots of money on testing and reviewing different aquarium products! You can find my reviews here.
Thant says
October 20, 2019 at 1:52 amHi Ian I have 4 rummy nose tetras. A few of them have developed white lips, or had them prior to me inheriting them. Some of their lips are more white than others But they are all active and eating well and their color is good. Water is good with 0 amm, 0 nitrite and about 10 nitrates. I was under the impression rummy nose are full red in the front? And they usually have weaker color if they’re sick? But I’m worried this is columnaris
Ian Sterling says
October 20, 2019 at 3:36 amHi Thant,
It’s really hard to say if it may have been there before you inherited them. If the lips are not flaking/fungusy then it may just be their specific markings.
Toni says
October 11, 2019 at 3:53 pmHi Ian,
I found your article on how to humanely kill your fish and have just put my beautiful betta down.
The tank was fine one day and then had a fungus growth in it the next day (I’m in Australia and the weather has been crazy hot, humid then cold), so I did a water change and checked with the pet shop about how to look after the water in this weather but the damage was already done to my fish. After the water change he just deteriorated so I googled fish euthanasia and found your article. Thank you for the advice, it worked quickly and he is now RIP.
Kind regards,
Toni.
Ian Sterling says
October 12, 2019 at 3:43 amHi Toni,
I’m so sorry to hear about your loss. Tanks can be difficult to maintain in fluctuating temperatures. I hope that this experience doesn’t put you off the hobby.
Wishing you all the best!
moe islam says
October 1, 2019 at 7:33 pmhi you say that Columnaris cant live in salt water. i have African cichlid that can tolerate certain amount of salt. will it help to add salt to my aquarium.
Ian Sterling says
October 2, 2019 at 4:49 amHi Moe,
If your fish don’t have it, it’s probably best not to add preventative measures.
Catherine says
September 29, 2019 at 11:46 amHi Ian!
OK, I’m pretty sure our new rescued betta has this. A couple of days ago he suddenly started acting “dejected” — just hiding, staying completely still on the floor, just darting occasionally to the surface etc — when usually he’s really active and friendly. We fasted him in case it was swim bladder, but of course no change, and then yesterday afternoon we noticed a sort of mooshy light patch on the side of his mouth. That’s the only visible patch; he doesn’t have the saddleback stuff or anywhere on his body, but I think it’s cotton mouth/columnaris yes? So we did a 25% WC and dosed with Kanaplex. THEN I saw your article and your routine with Furan. So my question is, since we started Day 1 yesterday with just the Kanaplex, should we just carry on with Day 2 with the Furan and continue the rest of the routine as described? OR shall we just go this round with Kanaplex only? Also, I’m presuming the med administration should be at about the same time each day (like with human antibiotics) yes? Please let me know as soon as you can, thanks soo much <3
Catherine says
September 29, 2019 at 1:03 pm*Forgot to also ask — we feed as usual during treatment, yes?
Catherine says
September 29, 2019 at 7:42 pmHi again Ian,
So ok, since it’s coming up to 24 hours since the first Kanaplex dose, and I haven’t heard back from you yet, shall we just go the Kanaplex-route this week and see how that goes? So the second Kanaplex dose will be tomorrow. Or.. ?
He was a very tiny touch perkier today, but really spent most of the day just staying still on the floor. That patch is still just there and nowhere else on him (visibly at any rate). Let me know your thoughts when you can please, thanks!!
Ian Sterling says
September 30, 2019 at 6:35 amHi Catherine,
Sorry about the delayed reply, I typically only answer comments once a day now since life has gotten so busy.
If you believe it is fungal and not columnaris, then just the Kanaplex alone should do it. If you think it’s columnaris, then the more potent 1-2 punch of Kanaplex and Furan would be needed to confidently eradicate it. Unfortunately, it’s difficult to diagnose fish online and I couldn’t quite say which it is – you’ll need to use your best judgement here with the information available.
If your fish will eat, then yes, feed as usual.
Catherine says
September 30, 2019 at 11:01 amHi Ian,
I understand, no worries, thank you so much.
Well today I think he has dropsy. The thingie at his mouth area is still there, but neither bigger nor smaller, nor anywhere else. However, today he definitely does have the dreaded pinecone look. I guess we’ll just continue with the Kanaplex alone for now, plus prayers! (p.s. if you don’t mind answering this, feeding while having dropsy is ok yes? thanks!)
Ian Sterling says
September 30, 2019 at 11:09 amI Hope it’s not dropsy, it’s a difficult one that not many fish come back from. While I have seen other fishkeepers beat it, Both times I battled it, my fish passed. My understanding is that you continue to feed as usual. Wishing you all the best here.
Catherine says
September 30, 2019 at 11:32 amSigh I’m pretty sure it is.. scales pineconing.. slight bloating.. we’ll see. This rescuing thing can actually be quite heartbreaking 🙁 Thanks so much again Ian.
Ian Sterling says
October 1, 2019 at 5:13 amI can imagine. I’m not sure I would have it in me to rescue fish – they just don’t bounce back as well from bad conditions as a dog or cat would. I truly admire you for doing what you do.
Catherine says
October 11, 2019 at 6:52 pmOh I’d missed your reply; thanks so much Ian.
I came on to ask if you knew how long columnaris survives in the tank if it’s empty — as in the fish has been moved to a QT. Could we keep dosing the empty tank with meds for say a week or two? We’d be sorry if the filters are gone cases 🙁
Ian Sterling says
October 12, 2019 at 3:50 amHi Catherine,
Columnaris is a tricky it’s a little unknown as to what the cause is. The current theory is that it’s always in the tank and attacks fish that are stressed or weak. If you can get your fish recovered and healthy, then columnaris shouldn’t affect them. Of course, there could be different strains or similar types of diseases that are misidentified, which make management harder again. With your fish out of the tank, I’d continue dosing for a few more days at most if it puts your mind at ease, assuming it is columnaris you identified.
Catherine says
October 12, 2019 at 12:42 pmThank you Ian!
Brenda says
September 25, 2019 at 12:23 pmI am pretty sure I have a tank with a few barbs that show signs on their lips of Columnaris (duck lips), already lost two of them and a several more are showing the beginning signs. I know people say QT the infected fish, but since several are showing signs I think it best to just medicate the main tank to ensure no other fish come down with it. Thoughts?
Ian Sterling says
September 26, 2019 at 7:16 amHi Brenda,
This is entirely a judgement call on your part. You can nuke the entire tank or quarantine. My personal preference is to go the QT route, since I try to avoid exposing healthy fish to medication, but either route will work. You know your fish and your tank best.
Miles says
September 16, 2019 at 8:42 amI had a betta in a community tank who I assume had columnaris. I noticed a white speck on Wednesday that grew double in size Thursday and Friday i put her in a quarentine tank and I dosed Kanaplex then dosed Furan-2 Saturday and went to lunch Sunday and came home to a dead fish. Her mouth was overtaken with the cotton. My question is should I dose the main tank she came from as well. I dont know if it’s my paranoia but my Harlequin Rasboras look slightly duller and all have a spot on top of their head between their eyes that I cant determine if it’s a marking or they are getting sick. All are swimming normal are active and eating daily. Neon Tetras seem normal and my cory catfish also seem normal. Would it hurt to do a round of treatment if none are actually sick?
Ian Sterling says
September 17, 2019 at 5:21 amHi Miles,
You should avoid treating fish with medication if you can help it, it can cause unnecessary stress which in turn *could* lead to illness. If memory serves correctly, I think Harlequin Rasboras can have markings on top of their heads, you may have to google here to make sure they match your fish. It’s would also be unusual for all fish columnaris in exactly the same spot on top of the head. Unfortunately, this is a judgement call that only you can make using the information you have available.
jessie says
September 8, 2019 at 11:35 amHi Ian… I am pretty sure that I have this problem with 2 of my discus fish. what would hbe the minimum temp to drop there water to. as they are normally in 30 degree water all the time. cheers Jess
Ian Sterling says
September 8, 2019 at 12:40 pmHi Jess,
Because all fish are different, you can only lower the temperature to their “comfort zone” You’ll have to research what is the low range for discuss and make sure you don’t drop the temperature lower than that. If you can’t lower it, then just skip that section of the advice.
Victoria says
September 6, 2019 at 11:40 pmHello, thanks for the information on how to treat this illness. I have practically no experience with fish, and now my betta looks like he’s sick. I’ve been researching different diseases, and so far columnaris seems to be the best match but I’m not sure. It started off with the scales on his back near his tail turning white and looking like they were flaking off. Now you can see pink flesh peeking out, like the sickness has eaten through to the inside. Does this sound like columnaris to you? As I said, I have no experience with fish and I don’t want to give him the wrong treatment, but I also want to help him get better right away. Thanks for any help you can give me.
Ian Sterling says
September 7, 2019 at 5:17 amHi Victoria,
Unfortunately, it’s impossible to diagnose fish through comments – I try to avoid it as it’s dangerous giving your fish medication that he doesn’t need.Unfortunately, you’ll have to use the symptoms above to attempt to diagnose it yourself, do more research or speak to a vet.
Hannah says
August 27, 2019 at 1:08 amHello!
I have a red male Betta that used to be my sisters. She kept it in atrocious condition and rarely (if ever) changed the water. When I took it from her and cleaned up the tank, the red fish started to turn black around the fins and gills. I’m not sure if this is Columnaris, and I’m a bit afraid to try treatment I’m case it’s not. The fish has been living like this (with the black on the fins/gills) for about 6 months and I only just received it a few weeks ago.
Any advice would be greatly appreciated.
Thanks,
Hannah
Ian Sterling says
August 27, 2019 at 7:00 amHi Hannah,
It’s possible it’s ammonia burns, if you grab a master test kit (the API one works best) you’ll have a better idea of what is going on in your tank.
You want to see:
Ammonia = 0
Nitrite = 0
Nitrate = Ideally less than 40
April Payne says
August 12, 2019 at 9:10 amI had a red betta who i first thought had gotten a flesh wound by cutting herself on a jagged resin decoration right next to one of her gills since she was acting normal and still had a good appetite. I took out the decoration, did more frequent water changes and added aquarium salt and catappa leaves to help with tissue healing. But then a week or so later she started laying on the tank floor a lot more breathing rapidly and the wound seemed to be getting fluffy looking. After getting advice from a betta fish keeper forum, i quarantined her (she was sharing a space with 4 cory catfish in a divided tank with another betta on the other side) and started dosing her with kanaplex since she had what i believed to be a fungal infection growing in her wound. She got worse quickly, she didnt have much of an appetite, ate only a little, all she did was lay on floor of the container and her scales seemed to be a little raised when i looked at her from above. I thought it was dropsey at this point, so i ordered some medication for that. She died before i could give her that medication. Does all this seem like it could have been columnaris or something else? I’m pretty confused. And since she was sharing water with other fish, what should i do about them? They all seem to look and act healthy..
Ian Sterling says
August 12, 2019 at 4:59 pmHi April,
Unfortunately, it’s difficult to diagnose online and it could be any number of diseases. It could even have come down to a single unhealthy fish due to the wound. If you other fish are looking and acting fine, I wouldn’t about them at this point.
Kate says
July 31, 2019 at 6:47 amHmmm…. I thought I might have finally figured out what was going on with my goldfish here but given the time he’s stayed alive (many months with this) it might not be this. I’m sort of at my wits end- is there any way I could get your thoughts, Ian? No one I’ve consulted at the aquarium stores has a guess at this point and you are the best.
He has one spot, white a appears fluffy in water but flat and slimy when out, and it’s not getting better. I set up a hospital tank; over the weeks I’ve hit him with API’s “General Cure”, “Fungus Cure”, and E.M. Erythromycin”, so we hit fungal, bacterial and parasitic. I’m using salts now too. It doesn’t seem to be changing.
I treated both goldfish (the other one had fin rot) and the 2 loaches (probably overkill) but finally, after sterilizing and cycling the main tank, just put them back in.
Ammonia, nitrites and ph are where they need to be. At this point, I’m just hoping to ID this growth so I know what to do next… if anything. Wish I had a way to upload a photo.
I really, really appreciate any thoughts. This site has saved my butt, down to the little details like getting the right thermometer. Thanks for everything!
Ian Sterling says
July 31, 2019 at 8:23 amHi Kate,
Is it expanding or growing? Has it been found on other fish? I only ask as if it’s been like this for many months, it may be something that has latched onto your fish and become stuck. What happens if you try pick it off (be very careful here and only do this if you are confident in what you are doing, tweezers and a steady hand are needed) if it can be picked off, wait and see if it returns?
The alternative is that if your fish appears happy, healthy, eating normally and behaving as usual is to just leave it. While it is possible that it’s columnaris, if this has been present for many months, it likely would have claimed your fish by now. If it is columnaris, a kanamycin/nitrofurazone combo will stop it in it’s tracks.
Unfortunately, even if I saw a picture, I’d probably be unable to diagnose it – many aquarium fish diseases look similar and have overlapping symptoms. If your aquarium stores are having trouble (they see *a lot* of diseases) diagnosing it, I don’t think I could do so by sight alone either.
Tina says
July 28, 2019 at 2:46 amThank you for your informative post. I noticed that two of my platys were acting strange (lethargic, not eating, hanging out at top of tank). Gradually one of the platys began developing white patches (body, lips). After reading your post, it looks much more like Columnaris than ick. We quarantined the fish and began treating the water with Melafix (treats bacterial infections). We gave this medication for 7 days, and much of the white disappeared. She is now swimming all over the tank but still isn’t eating and has a little bit of white and discoloration.
We also purchased both the Furan and Kanaplex you recommended. Now we have a dilemma. Should we continue with the Melafix for a little longer (even thought the bottle says to stop at 7 days) to make sure the fish is totally healthy, stop giving meds and wait/watch or begin the Furan/Kanaplex combo (using dosage you recommended)?
Also, how long should you wait before placing a recovered fish back into their tank? We don’t want to place her back in the old tank and expose our two babies to illness.
Your advice would be greatly appreciated!
Best,
Tina
Ian Sterling says
July 28, 2019 at 4:33 amHi Tina,
Diagnosing fish can be difficult and you will have to make a decision here based on what you believe the disease to be. If you believe that you are dealing with columnaris, then I would ditch the melafix and swap over Furan/Kanaplex if I was in your position.
Unfortunately, even if your treatment successfully removes the outside observable symptoms, if your fish isn’t eating then it’s only a matter of time before he gives up the ghost (generally, most healthy fish can go up to a week without eating). Have you tried using garlic to stimulate your fish into eating?
I personally wait another week or two, just to confirm that the fish has recovered. Depending on the size of your display tank, and it’s decorations/plants, it’s much easier to observe in a hospital tank – plus you won’t have to catch her again if you notice symptoms return.
gaël says
July 26, 2019 at 8:52 pmHello,
I try to do the treatment that you offer for my apistogrammas, but being in France is very complicated to get the 2 products,
I ordered furan 2 in the USA and for kanaplex the seller sent me Neoplex to instead, do you think I can do the treatment you are proposing with furan 2 and Neoplex instead of Kanaplex.
Best regards
Ian Sterling says
July 27, 2019 at 4:44 amHi Gaël,
If you can’t find those two products, then you would want to find an aquarium medication that contains the same ingredients (kanamycin for Kanaplex + nitrofurazone for furan for the active ingredients) I do not believe Neoplex will yield the same results.
Lauren Harrell says
July 21, 2019 at 8:07 amThanks so much for the information! It totally saved my oldest bumble bee cichlid when I combined the two medication. Now, dumb question, he has gone through the 5 days of treatment and there are no more visible signs of the disease. When do you suggest I put him back in his normal tank?
Thanks !
Ian Sterling says
July 21, 2019 at 8:31 amHi Lauren,
I’m really happy to hear you found success and saved your Bumblebee Cichlid – they are beautiful fish!
That’s not a silly question at all! The exact answer will vary according to who you speak to. I generally leave them in the hospital tank for up to another week once I have stopped medicating. This allows me to really closely monitor before returning them to the tank and also minimizes the risk of infecting the other fish, just in case there are still traces of the disease.
Beth says
July 19, 2019 at 6:48 amIs it possible to have bad drug interactions when adding a 3rd medication? My Betta developed ich on top of his Columnaris, and it seemed like the furzan/kanaplex was working miracles, until day 3 when I added ich treatment. He then went downhill over the next 5 days -now essentially blind, can’t see food, gasping for air. (I’m planning to euthanize him tonight.)
Thank you so much for this article. I wish I had found this a month ago, I think it would have saved my Betta. two full courses of erythromycin just didn’t clear his infection, and by the time I found your advice here I think it was too late. I’m going to read everything else on your site before I try this again.
Ian Sterling says
July 20, 2019 at 10:43 amHi Beth,
Treating multiple diseases at once is a nightmare. I’m sorry to hear you had to go through this. It’s possible that ich treatment was a shock to the system, or perhaps your betta was already far gone and the effects coincidentally aligned with when you added ich medication. Unfortunately, it’s really hard to say.
If you need any pointers or anything explained on the site, please comment that article and I’ll do my best to help. I hope you don’t give up on fish – once you have a handle on what to do, they are wonderful pets!
xnedranz says
July 15, 2019 at 4:54 amHello, my tank has columnaris and this article has been incredibly valuable, thank you! My question is this: in my country I can only get Furan 2. Nothing ending in -plex at all. It wont even get through customs. So what else can you suggest please? I have Khuli’s in the tank also which makes dosing more difficult. Thank you in advance for your advise.
Ian Sterling says
July 15, 2019 at 8:49 amHi Xnedranz,
Kanaplex is kanamycin based. Are you able to track any fish medicine containing that down? Unfortunately, I don’t have a whole lot of knowlege outside of the American market.
Chris says
July 4, 2019 at 7:57 amThank you for the informative post! I have recently been dealing with what I suspect is one of the less aggressive strains of Columnaris and have been treating for an extended period. I had gone through several cycles of various antibiotics, to no avail, before finding this post. The only thing I noticed any improvement from was a week-long salt treatment, which I upped to 3 tsp/gallon over the course of 3 days, but which still did not clear the symptoms. The meds I previously tried had included both kanaplex and furan-2, but I had used each individually per their instructions, unsuccessfully. Those were followed by a full course of sulfaplex, then the salt.
Anyway, I found the above post and decided to give the simultaneous kanaplex/furan-2 treatment a try. I have only the last double dose remaining to go tonight and all affected fish remaining in the tank appear to have been cleared of their symptoms (my remaining poropanchax luxophthalmus lampeyes look all clear, though I lost 2 females to the outbreak), aside from 1 cardinal tetra. This guy actually has some “cotton mouth” still hanging out. His color looks good and he is extremely active, as well as eating. He seems totally fine, aside from his mouth.
My question is, should I try to manually remove it? The lampeyes all just got white lips, aside from one of the lost females whose lips both turned white and looked like they were started to disappear, giving kind of a skeletal look before I lost her. The tetra is the only one who develop this… protrusion, which hangs off of one side of his mouth and doesn’t seem to be going away. I tooks some pics, but I don’t see an option to include them here. Any insight would be appreciated.
Ian Sterling says
July 4, 2019 at 1:18 pmHi Chris,
It’s crazy how often I hear people try both medications independently not achieving the same results. I’m glad to hear using the two together has seen a dramatic improvement in your fish – also, congratulations on your diagnosing skills, it means you successful identified that your fish had columnaris which can be a mission in it’s own right. Congratulations again on successfully treating your fish!
As for your question, Manual removal would be problematic. If it is cotton mouth, the spores left behind will still be present. Malachtite green or salt is generally effective at removing it. Given you have already used a salt treatment, I just want to clarify that you are confident it is cotton mouth disease? Sometimes when the “skin” splits at the mouth, brought on by columnaris, it leaves clear white bits poking out that can sometimes be confused for cotton mouth.
Chris says
July 4, 2019 at 9:52 pmI honestly don’t know. I guess that would make sense. The best way u can describe it would be a whitish or light grey protrusion from one side of the tetra’s mouth. It has not responded to any of the treatments I have attempted, so maybe that’s why. If it is in fact split “skin,” do you think it will just remain the same, or will it eventually fall off? Like I noted before, the fish seems entirely unaffected… active, hungry and fully colored up. His lips are no longer white, either.
Ian Sterling says
July 5, 2019 at 4:59 amIt’s hard to say. If I was in your shoes, and had tried treating it with cotton mouth treatments, I would take a “wait and see” approach. Unfortunately, I could only guess as to whether or not this will go away. If it is a physical wound then it will look likely look better over time but will possibly scar.
Chris says
July 6, 2019 at 9:06 amThanks for the advice and for responding so promptly. Much appreciated.
Ian Sterling says
July 6, 2019 at 12:11 pmMy pleasure, I hope it’s as I suspect and just a physical wound – it sounds like you have been through enough medication as it is!
steve says
April 30, 2019 at 2:02 amThanks for sharing your knowledge. I have 2 different medicated flake foods, 1 has oxytetracycline, the other, kanamycin. Which one would be more effective?
Ian Sterling says
April 30, 2019 at 8:06 amHi Steve,
From my understanding, Columnaris is gram negative and oxytetracycline is largely a gram positive treatment, which won’t help treat columnaris. Of the two, Kanamycin would be more effective. However, I still prefer my 1-2 punch method above, which doses the water.
Katie says
April 26, 2019 at 11:14 pmWould it be advisable to treat the tank even if all the fish are dead and gone? I ask because I lost all my fish quickly and wonder if the bacteria are still present.
Ian Sterling says
April 27, 2019 at 8:09 amHi Katie,
It entirely depends on whether your fish came down with columnaris or not. There are plenty of diseases that have similar symptoms, some will require you to disinfect your entire tank while others are less of a concern.
Kurt Mankurt says
April 24, 2019 at 8:48 pmHi Ian,
great job, really useful, practical and solid source of informations about this desease, thank you.
Mankurt
P.S.:
Your citation (under the photo):
„As you see, when viewed under a microscope, the bacteria resemble rods or columns– yep, that’s how this bacteria got its name.“
Here is slightly different and more detailed opinions how this bacteria got its name – its not the shape of solitary bacteria cell, but rather column-like formations of many of them.
„The columnaris bacteria can be differentiated from other bacteria by their size and shape (long, thin rods, 7 to 10 millimeters and approximately 10 to 20 times longer than wide); their movement (flexing and gliding); and the formation of “haystacks” (bacterial cells that form columns on the surface of tissue).“
https://appliedecology.cals.ncsu.edu/wp-content/uploads/479.pdf
„With a microscope, scrapings from a columnaris lesion then placed under a microscope will reveal long, thin, rod shaped motile bacteria. The bacterial clumps form microscopic columns or dome shaped masses, hence the name columnaris.“
Kurt Mankurt says
April 27, 2019 at 12:36 amErrata: ” …7 to 10 micrometers …”, of course. Sorry.
Mankurt
Ian Sterling says
April 27, 2019 at 4:55 amHi Kurt, Thanks so much for elaborating, this information is fascinating!
Fagan says
April 12, 2019 at 6:45 amI’ve been fighting this disease in my tank for about a month.
I have a 29 gallon tank, and I used to do a 5 gallon water change every 7-10 days, and never had any problems.
I suddenly lost three neon tetras and a dwarf guorami over a just a couple of days with white stuff around their mouths, a big red sore on the side of one fish, and one fish lost part of its tail.
So, I started treating the tank with a combination of both Metroplex and Kanoplex every other day, along with a 5 gallon water change, every other day (water was heated to the same temperature, and treated with a chlorine remover/conditioner).
Near the end of that treatment, everything looked better, but then a few days later, one of my fish started having white fuzz around the mouth, and with scales below its mouth looking loose.
Over the last two weeks I’ve been dosing the tank every other day with Melafix, and changing out 5 gallons of water every other day (heated and conditioned water).
The fish perked up, until yesterday (day 10 of the Melafix cycle), and today two of my fish look like their entire lower jaws are missing.
Advice?
These two fish are so far gone, that I’m wondering if I should euthanize them?
Should I consider sterilizing the entire tank, and starting over with new rocks and everything? I would put the remaining fish in a smaller tank to set up the new one…
Ian Sterling says
April 12, 2019 at 12:30 pmHi Fagan, I’m terribly sorry to hear that things have gone sour in your recovery efforts. Unfortunately, I am not qualified to diagnose fish. However, I will say that if I was in your situation, based on what you have described, I would likely consider euthanization. It’s a judgement call only you can make and not one to be made lightly.
As for sterilizing, It’s a tricky one as this will essentially crash the cycle of your tank. You’ll basically need to cycle any tank you add your fish to all over again. Since you still have fish, you’ll need to perform a fish-in cycle which is stressful and can also kill fish. It’s kinda a lose – lose situation and again, a call only you can make.
Noel says
April 5, 2019 at 8:31 amHello,
I was wondering if the level of furan-2 in the tank could possibly be harmful to my Betta with this course of treatment? I’ve read how this medication is particularly strong, and how it is a possible carcinogen (which should be written in bigger letters on the box).
Ian Sterling says
April 5, 2019 at 5:01 pmHi Noel,
A lot of chemicals that fall under “medication” are not the best for fish, however, in many cases, it’s trading a certain death sentence from the disease, for the possibly negative effects of the medication.
As for Nitrofurazone being carcinogenic, the last time I read studies, there was inadequate evidence for carcinogenicity in humans. I vaguely recall a study where rats fed nitrofurazone had a higher incidence of cancer, but let’s face it, it’s obviously not designed to be consumed. If there is a new study, I would love to read it.
Andrea says
April 1, 2019 at 9:27 amGreat and informative article!
What do you look for to determine if the infection is enough to warrant 2 rounds of kanaplex + furan-2 vs 1?
Ian Sterling says
April 1, 2019 at 11:19 amHi Andrea,
That’s an excellent question. It entirely depends how far along the columnaris infection was before it was treated and if there are any remaining tell-tale signs. To be honest, I have only ever needed a single round of these two treatments, it’s an effective remedy. In all the cases where my fish lived through it, they have made a full recovery. My last experience battling columnaris was years ago. However, after discussing this topic within my local fish club and speaking with other experienced Aquarius, there are times that you may need a double dose – anecdotally, it appears there are different strains, some of which while still responding to the medication do so at a slower rate.
Denisa says
March 24, 2019 at 10:47 pmI’ve been told Kanamycin will wreck the kidneys of goldfish. Anyone have experience with using kanamycin on goldfish? Life expectancy of a fish that recovered from Columnaris using kanamycin?
Warmly,
Denisa
Sarah Par says
March 24, 2019 at 1:43 pmHi How do I medicate tetras using kanamycin? Its the only one I could get in Aus.
Do I dose a half dose?
Ian Sterling says
March 24, 2019 at 2:33 pmHi Sarah,
Did you buy it as a fish medication? If so, simply follow the instructions. However, if you can obtain nitrofurazone combining the two together results in a higher rate of success for Columnaris in my experience.
Tauseef Ahmed Faryaz says
January 21, 2019 at 4:40 amHi again ..
I wish i had read your blogs 2 weeks ago. I lost 20 of my female bettas because of this. But i dint know how to treat them. After that i dried my whole aquarium and its decorations in sunlight for a day and again filled well water and added 7 females more. Now 2 are stressed and looks like they developed dropsy(raised scales)moved them to a seperate small tank. If you mail me back i would like to share some of pics of my old bettas and would like to know was it the same or other. So that i can be ready further.
Ian Sterling says
January 21, 2019 at 6:10 amHi Tauseef,
Unfortunately, outside of comments relating to my articles, I do not give individual advice. It’s a stance I have had to take, before I was spending 3 hours of my day answering individual questions, and that’s when my site was considerably smaller. Unfortunately, as much as I want to help everyone, as a single person, I just don’t have the time. I barely have enough time to work on new articles for this site as it is. I suggest joining a forum, plenty of fish keepers will be able to help you.
Christy says
February 17, 2019 at 12:44 amYeah, there are tons of online forums and fish groups on facebook. I suggest doing some online research. You really shouldnt just add fish to a tank. It needs to be cycled properly first. So hop on over to google or facebook and get started. Theres a ton of great info and ppl happy to look at your photos and give you some help.
Jodi Lynn Wisneski says
June 26, 2019 at 8:00 amHi, thank you so very much for this article. I have done back to back doses of the Kanaplex/Furan-2, but I am still seeing some of the white film on my Rasboras. Should I risk a 3rd full treatment or just try the Furan for a 3rd round?
Ian Sterling says
June 26, 2019 at 10:11 amHi Jodi,
Assuming it is columnaris, have you been noticing improvement since you started medicating, did the disease respond to this treatment? Also, is the white film damaged skin or does it look like the disease you have been fighting? If it is columnaris your fish must have had a severe case, all instances I have observed have cleared in two rounds and the ones that didn’t, the fish was too far gone to save. That isn’t to say that what you are dealing with isn’t columnaris.
If you suspect it’s a columnaris infection, and you noticed that treatment has been working so far, it makes sense to continue dosing. However, this is a decision that only you can make.