FISH COLUMNARIS |
Fungus & Saprolegnia | Treatment & Prevention

THE BEST AQUARIUM TREATMENTS/MEDICATIONS VIDEO:

AAP Professional Aquarium & Pond Medications

Treatment Information:

STEP ONE:

The obvious first step is lowering stressors and improving water parameters (not necessarily just "clean water") as outlined in these sections of this article.
If you have jumped to treatment and not read these other sections; STOP now and please read these sections too!

* What is Columnaris

* Identification & Causes

* Prevention

* Parameters to Consider for Prevention and Treatment of Columnaris
This includes mineral Cations and lowering oxidative stress.
This also includes lowering water temperature to 75F (24C).

This article is A MUST READ before moving on to treatment too:
Fish Diseases | How to Treat Sick Fish

Failure to follow step one and just treating with medications is akin to asking someone for burn relief medications while still standing in a fire!

STEP TWO:

Additional salt is helpful at a dose of 1 tablespoon per 5 gallons OR HIGHER (such as one teaspoon per gallon).

Please keep in mind that this amount of salt is NOT meant for long term use, rather just the duration of time it takes to reach a cure for the Columnaris infection.
This amount of salt is most simply used in a 30 minute bath, however as per this study it can be used in the main display aquarium/tank.

As an alternative to medications; a study at the Alabama Agricultural Experimental Station, Auburn University has shown increasing salt concentrations used with Channel catfish (along with heat reduction to 75 F) can treat Columnaris (Flexibacter) infections. This study flies in the face of anecdotal advice about not using salt with catfish.
See the chart to the above/right for the mortality rate of Catfish with Edwardsiella ictaluri (which is a similar gram negative rod bacteria to Columnaris) treated with salt at different levels, please click to enlarge.
References:
*Alabama Agricultural Experimental Station, Auburn University

You can see from the diagram that the best results were achieved at a dose of 3000 milligrams per liter; based on the weight of salt this converts .67 teaspoons per liter or 2.54 teaspoons per gallon. This is Much more salt than many aquarists commonly believe a Catfish can tolerate.

Readers should also note that fish losses were still higher than medications combined with swabs/baths based on my own experience with 100s of Columnaris treatments for clients. Fish farms generally cannot use antibiotics for fish being raised for human consumption, thus this alternative treatment..

If added to the main aquarium, I recommend building up to high level suggested by this study over a 2 day period AND done in a hospital tank ONLY AND NOT combined with medications as 2.5 teaspoons per gallon salt mixed with therapeutic levels of medications may be lethal to the fish too.

STEP THREE:

A Fish bath and/or swab: A bath using Methylene Blue (not to be confused with malachite green), or Potassium Permanganate has also helped speed cure in most instances for my client's fish (or my personal fish) and SHOULD BE part of most Columnaris Treatment regimens!

AS WELL, a direct swab of "AAP Wound Control" (Merbromin) has been very helpful from my experience for Columnaris external lesions of all kinds, except for those within the gills.
The effectiveness of Merbromin lies in the fact Merbromin is an organomercuric disodium salt compound and a fluorescein that is effective on external infections because of its permanence, and lethality to bacteria, IN PARTICULAR COLUMNARIS!
Reference: Aquarium Fish Merbromin External Columnaris-Bacterial Treatment

Caution, do not use Potassium Permanganate with open sores present or directly on gills, it should also be diluted 50/50 with water before direct application (AAP Merbromin/Wound Control is still your best choice for Columnaris followed by MethyBlu).

Product References:
*Merbromin (Wound Control); from AAP
*Potassium Permanganate; from AAP
*AAP MethyBlu Premium Concentrated Methylene Blue (recommended over standard MB))
*Kordon Methylene Blue 4 oz, from AAP

In fact with many instances of Columnaris the Methylene Blue Bath (or the even more strong, but more carefully administered Potassium Permanganate bath) was the main factor of treatment that affected a cure as per many tests.

See the picture above/left for a Betta also displaying secondary Fin Rot that literally was on "deaths door" (laying on the bottom with little response) that recovered with a treatment regimen of Spectrogram & Salt as well as regular fish baths which included Methylene Blue, Salt, and AAP Spectrogram (synergistic Kanamycin/Nitrofurazone).
Please click to enlarge.

The Bottom line is a Fish Bath and often a Merbromin (AAP Wound Control) swab too is a MUST part of any moderate to serious Columnaris infection treatment!!

With Methylene Blue OR Potassium Permanganate I prepare a double strength bath and place the fish in this solution for 30 minutes).
I strongly recommend this bath as a FIRST course of action.
AAP Spectrogram (1st choice) OR AAP Bettamax (2nd choice) OR Furan Two AND Kanamycin (3rd choice) SHOULD be added to this 20-30 minute bath for more serious or stubborn cases, HOWEVER do not combine these medications or any others with Potassium Permanganate, ONLY Methylene Blue can be combined.

AAP Bettamax at double dose can be substituted for Methylne Blue and other meds for a bath as it duplicates many of the best ingredients for a fish bath in a ready to use measured capsule (1 capsule per 2.5 gallons of bath water).

Product Resources:
*AAP Spectrogram (Nitrofurazone/Kanamycin Sulfate Combo)
*AAP Bettamax Combination of Nitrofurazone, Methylene Blue, PVP, Vitamins, NaCl, Sulfas: methazine, diazine, and merazine (pharmaceutical grade)
*Furan 2, Nitrofurazone; from AAP (Vastly Superior to Furan 2)
*Kanamycin,; Kanaplex from AAP

Please see this article for more about Baths:
“Fish Baths, Dips, Direct Treatment Applications”

As well as the above noted baths, direct applications (swabs) of Methylene Blue for mild cases of Columnaris applied to external areas of infection can help with recovery.
Methylene Blue can be improved as a swab by adding sulfa drugs or more simply by mixing equal parts of Maracyn Plus (Sulfamethazine and Trimethoprim) & MB and applying this swab. A similar combination using a now discontinued "Aquatronics" product worked well to check infection spread directly on some fish.
For more serious cases, Hydrogen Peroxide or Diluted Potassium Permanganate applied as a swab may be your only chance to check the spread of a more serious infection of Columnaris.
Make sure NO Potassium Permanganate gets into the gills, if this happens, a 2-3 normal dose of SeaChem Prime or similar product added to a fish bath and used immediately for this fish is suggested.

Product Resources:
*Maracyn Plus from AAP

Reference for use of Hydrogen Peroxide: Aquarium Medications 3, Hydrogen Peroxide

STEP FOUR:

In tank or hospital tank treatment:
Many fish diseases, it should be noted, are caused by different bacterial or fungal pathogens that often exhibit similar symptoms, so identification of a specific bacterial or fungal pathogen is not often possible from mere visual inspection of the symptoms on the fish.

By using broad-spectrum treatments such as a Nitrofurazone (AAP Furacyn or less effective Furan Two) & Kanamycin COMBINATION against diseases with similar symptoms affecting fish, precise identification of specific bacterial or fungal pathogens causing the disease that often display similar symptoms may not be absolutely necessary.
AAP has finally been able to bring back this combination of already blended pharmaceutical grade Nitrofurazone/Kanamycin in the product AAP Spectrogram!
This is easier to use & more effective than previously combining (which included slightly different use instructions for Kanaplex & Furan 2).

Besides the synergistic combination found exclusively in AAP Spectrogram, the other reason to use this over separate dosing of Nitrofurazone and Kanamycin is that the aquarium keeper can readily perform an important 10-20% water change before each treatment (to improve effectiveness), which is not really possible without affecting therapeutic levels with the separate combination due to different treatment schedules. As well, Spectrogram can be safely doubled in dose for difficult cases (unlike separate treatments)
Resource:
AAP Spectrogram (Premium Nitrofurazone/Kanamycin Sulfate Combo)

As previously noted, a water change prior to each treatment of AAP Spectrogram is suggested as this increases effectiveness of the medication and generally improves water conditions too. I strongly suggest using the premier water conditioner; AAP Res-Q with each water change (then waiting 30-60 minutes before adding meds).
AAP Res-Q is vastly superior as per long term professional use over products such as Stress Coat as it is better at leaving a slime coat which is also adds a unique slime coat too that no other water conditioner does.
Product Resource: AAP Res-Q Water Conditioner (this is a product no serious fish keeper should be without)

Please note that the combination of BOTH Kanamycin AND Nitrofurazone MUST be used for effect against true flavobacterium columnare infections, otherwise the minimum inhibitory concentration (MIC) values of these medications individually is too low.

I have also noted reports that while I have enjoyed good success with the above treatment method, assuming water parameters were spot on (including Redox and water temperature), that the failure rate is increasing.
This can be and likely has a lot to do with over breeding of certain fish such as many Bettas, resulting in weak genetics.
However antibiotic resistance is also likely on the increase, which is why this antibiotic combination should not be used on a regular basis every time your fish "burps".

Since the use of Nitrofurazone/Kanamycin is a synergistic combination (when used 100% at the same time), improving synergistic combinations via new research into human antibiotics resistance is yielding some interesting results with Oregon Grape Root which aids in antibiotic effectiveness as it contains a specific multi drug resistance pump inhibitor (MDR Inhibitor).
Resistant bacteria work by utilizing a pumping mechanism in its cell that when antibiotics enter that cell the pump immediately pumps out the antibiotics so it can have no effect on the MRSA cell. Oregon Grape Root works by blocking the bacteria's ability to pump out antibiotics.
Currently the best suggestion for use is opening a 400 mg Oregon Grape Root Capsule into 10 gallons of water along with the antibiotics, but keep in mind, aquarium use is still in its infancy!!!

Reference: Oregon Grape Root - It could save the world

With severe quick moving Columnaris infections that have entered the bloodstream via a gill infection (as noted earlier in this article), combining Kanamycin, Nitrofurazone and Medicated Wonder Shells is a strong option that address mineral Cations and also helps with osmoregulation and blood issues. Unfortunately once this infection goes systemic, the odds are bad, but this is one of the few viable options at this point (assuming all stressor corrective issues have already been addressed).

Resource:
Medicated Wonder Shells (patent pending)

OTHER TREATMENTS;

Ciprofloxacin can be an effective synthetic broad spectrum antibiotic against gram-negative bacterium such as Columnaris and can be used in tank or in baths.
The difficulty is finding this antibiotic in small quantities as most is sold in large volumes at high prices (beware of eBay sellers at low prices of this antibiotic, as it is often outdated as per the manufacturer).
Also note that Ciprofloxacin does not mix well in higher GH water and chelates mineral Cations, similar to Tetracylines and this limits is usefulness, especially since the optimum water conditions for cure/prevention are the very same water conditions that inhibit Ciprofloxacin effectiveness.

Triple Sulfa or products containing Sulfas MAY also yield positive results for treatment of Columnaris if used early, although this is not as effective of a treatment for Columnaris as it used to be or as the Spectrogram (Kanamycin/Nitrofurazone combination).
If Sulfa drugs are combined with Trimethoprim or especially with Nitrofurazon (as with the product Bettamax which combines sulfa & Nitrofurazone), this also yields a more synergistic effect that can and does work reasonably well in cases of Columnaris that does not respond to the Nitrofurazone/Kanmycin treatment.
The only caution is that Trimethoprim can be a problem with fish with large bleeding sores, so if such sores or similar are present, it should not be used.

My professional use of Triple Sulfa has found that it is occasionally a good choice along with lowering stressors, baths, and some salt for mild to moderate infections and is rarely harsh on aquarium environments including plants.
I stand behind Triple Sulfa as a possible alternative treatment. This despite a rude/condescending comment brought to my attention from Guppies.com. As well, this person is incorrect as per the use of a level 1 or higher UV Sterilizer, as it is excellent prevention for Columnaris, including the very well researched FACT it improves the Redox Balance.
As to his condescending remarks about me personally, Yes, I have done copious amounts of research (which many are cited here, including the use of Triple sulfa and other products containing sulfa drugs), as well as my consulting with one of my mentors, Dr. Herzog and research by Daniel W. Slater of the US Fish and Wildlife Service.

Product Resources:
*Triple Sulfa from AAP
*AAP Bettamax Combination of Nitrofurazone, Methylene Blue, PVP, Vitamins, NaCl, Sulfas: methazine, diazine, and merazine (pharmaceutical grade)
*Maracyn Plus with Sulfamethazine and Trimethoprim

Doxycycline is one more alternative that may work and is readily available to the aquarium keeping market. Doxycycline is the only member of the Tetracycline family that I would recommend for a true Columnaris infection.

Product Resource:
Doxycycline (Fin & Body Cure) from AAP

Unfortunately, there is much unfortunately posted in forums or websites about the use of Tetracycline or Oxytetracyline for the treatment of Columnaris however this is based on old research and misunderstanding of the large Tetracycline class of medications.
Unlike Doxycline, many Tetracyclines are primarily gram positive while Columnaris is a gram negative rod bacteria (although Oxytetracycline is more broad spectrum than Tetracyline Hydrochloride, it is still primarily a gram positive treatment).
This said, Doxycycline and to a lessor extent, Minocycline, are also members of this class of Tetracycline antibiotics. Minocycline (sometimes spelled Minocycline) is more gram negative than its cousins and has shown SOME effectiveness for Columnaris (although Doxycycline is the better choice of the two).
That said, the Tetracyline family of antibiotics should never be your first choice of medication treatment, despite some misinformed information stating otherwise (please note that I make this statement based on researched medication facts as well as MUCH practical experience dating back to 1979).

References:
*Aquarium Medications Part 2; Tetracycline
*Aquarium Medications Part 2; Oxytetracycline
*Aquarium Medications Part 2; Minocycline

Pimafix can aid as a natural "in-tank" treatment for VERY MILD cases of Flexibacteria in combination with lower temps, salt, improving stressors (including oxidative stress), and baths (I would NOT recommend it for more moderate to serious cases). Do not confuse Melafix with Pimafix, as Melafix is more of an antiseptic with no effect on Columnaris whatsoever!
Pimafix is sometimes effective for a broad range of mild bacterial and fungal infections that typically afflict fish and other aquatic animals (especially gram negative). Fish diseases that may be treated in accordance with this product include bacterial fish diseases, such as fin and tail rot, mouth fungus (often caused by the bacterium Flavobacterium Columnaris); fungal fish diseases (such as those caused by microorganisms of the genera Saprolegnia and Achyle) and the like.
Product Resource: Pimafix from AAP

ADDITIONAL FOLLOW UP TREATMENTS;

Among other treatments I have used, especially to prevent reoccurrence once the fish are OK might include AAP Bettamax or “AAP Medicated Wonder Shells”. AAP Medicated Wonder Shells contain Acriflavin (as well they contain Methylene Blue).
Acriflavin is active against flex bacteria in mild cases.
While I do NOT recommend Medicated Wonder Shells for a full blown infection of Columnaris these can be an excellent follow up treatment about 7-10 days after completion of regular treatment and baths. These are helpful in part for a Columnaris infection due to the positive mineral ions they deliver along with medication.
I do suggest a water change and adding carbon to filters prior to the introduction of a Medicated Wonder Shell, or other follow up treatment.
Reference: Aquarium Medications Part 3; Acriflavin

AAP Bettamax is a good preventative treatment ESPECIALLY for long finned fish such as Betta and fancy guppies

Product Resources:
Medicated Wonder Shell; ONLY available at AAP
*AAP Bettamax(Combination of Nitrofurazone, Methylene Blue, PVP, Vitamins, NaCl, Sulfas: methazine, diazine, and merazine)

FINALLY, in summary of treatments; one aspect I found over and over, including when I have compared notes with other aquarium maintenance professionals is that attempting to mix a little of one method of treatment with another almost always results in failure.
In other words, if you have found a treatment you have found that works that differs from what I have stated, GREAT!
But do NOT attempt to mix what is suggested here by leaving out some aspects of these treatment steps (or another methods) and expect success.
Also as I have already noted, do NOT leave out the importance of correct water parameters, in particular positive mineral ions play in the success of a Columnaris treatment regimen.

PREVENTION & FURTHER COLUMNARIS (Flexibacter) INFORMATION:

Flavobacterium columnare gained the nick name “Columnaris” because wet mounts of Flexibacter prepared from diseased fish appear as column-like, "haystack" colonies.

Columnaris, which is a gram negative strictly aerobic bacterium, is often prevalent in systems with poor mineralization, but not so much water high in tanins and other dissolved organics.
Columnaris is "Ubiquitous", meaning it is found everywhere, however its presence does not necessarily lead to Columnaris disease.
For these reasons, those who state that low oxygen levels can cause Columnaris along with the need to euthanize surviving fish (& sterilize the aquarium) are providing 100% INCORRECT information.

Also reference this article: Aquarium Chemistry; The Importance of Calcium, Electrolytes and more.

As well; crowded conditions (often in re-circulating systems), aggressive inhabitants, poor handling, poor Redox Balance, sudden temperature spikes (or prolonged temperatures much above 80F), and the stress from high bio loads are all conditions that can allow for an opportunistic Columnaris infection.
Please note; high bio loads is more symptomatic of Aeromonas or Saprolegnia infections.

Reference: Aquarium Redox Balance

Columnaris bacterium have caused problems for fish farmers for many years. It is not easy to control, and because the disease is related to stress, an effort to identify and correct the source of the problem is necessary to prevent excessive or chronic mortalities.
Fish are particularly vulnerable to Columnaris following handling and transport, especially since Columnaris is opportunistic warm water pathogen that is often always present in the water, it simply needs an “opportunity” to become pathogenic.

Abrasion from nets, transport, crowding, aggression by tank mates, and adverse water quality conditions (such as lack of necessary electrolytes/minerals) create a situation which is very conducive to Columnaris outbreaks.
With this in mind; lowering stress (such as removing an aggressive inhabitant), improving minerals/electrolytes, and keeping a clean well filtered aquarium are first steps in treating or preventing Columnaris.

Parameters to Consider for Prevention and Treatment of Columnaris:

Please note that if ANY of these parameters are "off", it may be difficult or even impossible to effectively & completely cure a serious Columnaris infection even if the most effective Columnaris treatment is used (AAP Spectrogram & Wound Control/Merbromin topically)!
The results of NOT addressing these parameters and stressors is often a reoccurrence!!
Remember that Columnaris is a disease of opportunity (that is often already present), so even though one may have an otherwise well maintained aquarium, any of these stressors could make it easier for Columnaris to get a foothold in a compromised fish.
There is no mystery here based on my decades of experience, yet this seems to be a part of the Columnaris puzzle so often missed!

*Decrease Fish Load, Crowding Columnaris outbreaks have been shown in University studies to be prevalent in crowded, re-circulating systems, which is a reason I recommend against these types of systems even for fish stores.
This is also common in “African Cichlid” tanks or similar where there is constant stress due to constant battling for hierarchy.

*Ammonia, nitrites; should be 0 ppm

*Nitrates (long term exposure of nitrates over 80 ppm can reduce resistance to disease, under 40 is better)

*Lower your temperature; under 75 F (24 C) (only during treatment).
Goldfish and similar cooler water fish should always be kept under 80F (27C) whenever possible.

*pH (depending upon fish kept) Stability is more important than the actual pH. In other words, do NOT chase you pH, find a KH above 50 ppm and keep your pH stable at whatever pH you get, whether 6.5 or 7.5

* KH: generally a KH of 50 + (what is best here depends upon fish kept). This is related to pH and maintains pH stability via adequate carbonates

*Positive Ionic Composition of the Water & GH: this is a little more complex than this article will deal with, however this is related to both the GH and Redox.
In a nutshell MG++ (positive magnesium ions) and CA++ (positive calcium ions) play a part in lowering oxidative stress. However it is noteworthy that one can have too much of a good thing, as a high GH of 400+ can allow Columnaris more readily adhere to gill filaments, so just like many "beneficial" methods, correct dosing is important!
This is important, please read this article for further information:

Aquarium Chemistry; GH, Calcium, Magnesium, Positive Mineral Ions/Cations.

VIDEO: Aquarium Redox Part 2 | Oxidizers & Reducers | AAP Wonder Shell Experiment
This video demonstrates the affect of oxidative stress and how mineral Cations act on oxidizers within the aquarium water column.

*Redox Balance; although often not generally a major concern for the average aquarist, it is important to understand when problems persist especially since advanced aquarium keeping research shows its importance in disease prevention.
In particular, this is an important consideration for an aerobic bacterium such as Columnaris, since often other more obvious water parameters may be good while this one is not.

Redox balance is related to GH (although if all positively charges ions are lost from calcium and other minerals that make up GH, you can still have a higher GH of say 300 ppm and still have a poor Redox Balance).
But the point I want to make is that websites such as Wikipedia and many others are dead wrong to imply that "The bacteria can persist in water for up to 32 days when the hardness is 50 ppm or more" is a causative factor for Columnaris.

While Columnaris Bacterium certainly utilize these minerals, so do fish. So to make the strange leap of thought to state any GH over 50 can lead to Columnaris (over 400 ppm might be a problem and definitely over 500 ppm is a problem). This is simply bad science, not to mention proves a lack of practical experience on the part of authors of these articles.
The fact is 50 ppm is a very low GH, even for many soft water fish and more importantly these minerals are essential for correct osmoregulation and a supplier of essential positive electrolytes necessary for fish immunity that Redox research has proven.

It is noteworthy that a higher GH plays an important role in adhesion of Columnaris by reducing surface potential and repulsive forces (both positive and negative depending upon levels). HOWEVER the importance in mineral Cations in CORRECT AMOUNTS plays an even bigger role in osmoregulation and lowering oxidative stress which is needed by fish to repel a bacterial infection.
So for an aquarium keeper to attempt to lower minerals and positive mineral ions is misguided at best unless GH numbers are "off the chart".

What is often missed by those advocating soft water is that the soft water found naturally such as in the Amazon actually has these ESSENTIAL mineral Cations, albeit in low levels (just ask Discus authorities such as Marc Weiss).
HOWEVER often artificial soft water made from RO or DI water often lacks these mineral Cations in the amount needed to aid in fish osmoregulation and for Redox balance. Often rH tests will confirm the unhealthy numbers.
In the end, we have to remember that many pathogens such as Columnaris are often present, but it is building up the fish' immunity and lowering stressors that will be most beneficial, NOT attempting to drive out essential minerals unless truly at very high numbers.

Please Reference: Aquarium Redox Balance; Importance in Fish Disease Prevention

*True Level 1 Capable UV Sterilizer; Related to Redox is the use of a TRUE level one or higher UV Sterilizer. This cannot only lower Columnaris bacterium in the water column, more importantly a UV Sterilizer lowers oxidizers in the water column that can and do cause oxidative stress which then provides an opportunity for Columnaris. A cheap clarifying UV purchased from a discounter is not the answer here either.
Reference: UV Sterilization; Facts & Information

* Diet: many aquarium keepers may not link this to Columnaris, and in fact the link is not direct.
HOWEVER, I have also found based on my experience and tests that a fish that is not in optimum health because of a less than optimum diet IS IN FACT AT A HIGHER RISK FOR COLUMNARIS!

An optimized fish food is best that does not need to supplement with added vitamins due to "cooking out" of ingredients.
By optimized I mean the ingredients are what the fish need IN OPTIMIZED PERCENTAGES, not the more is better approach as most prepared fish foods as 95% of fish foods OVER DO proteins & energy. This includes the majority of so-called premium prepared fish foods.

WHY? Because, as an example, excess or un-digestible protein are a common cause of kidney (renal) failure and this allows opportunistic pathogens to get a foothold.

As well, too much energy results in fatty liver issues which increases oxidative stress which then lowers disease resistance, especially to opportunistic infections such as Columnaris in particular.
Unfortunately EVERY fish food sold (even so-called premium brands such a New Life Spectrum, NorthFin, etc.) other than Clay Neighbor's AAP Custom do NOT follow guidelines set forth in a University study as well as long term experience by myself as to optimized energy levels.
The bottom line as per diet is; while changing your diet when the fish already have a Columnaris infection will do little, HOWEVER prevention and checking spread of this opportunistic infection is definitely improved by switching to a TRUE optimized premium diet such as Clay Neighbor's AAP Custom!

Further Information:
*YouTube Video; Fishfood Label | How Much Energy
*Fish Nutrition; Complete Information

My suggestion would be Clay Neighbor's "AAP Custom All Natural Optimized Fish Food"

*Consider ALL steps outlined in this article: “A Healthy Aquarium; Disease Prevention”.

*Good filtration (two filters is always a good option), is very important for treatment and prevention. It is important to catch this disease early, as Flexibacter advances it attacks the internal organs making for more difficult treatment. The Nitrofurazone/Kanamycin combo is about the only antibiotic that will work at this time (unless you have access to Chloramphenicol).
This said, circulation and dissolved oxygen do not play as big a role as with the diseases Aeromonas, Furunculosis, or Vibrio, since Columnaris is a aerobic bacterium that needs oxygen while these others are anaerobic meaning they do best in environments without oxygen.
Reference: Aeromonas, Furunculosis, & Vibrio Infections

*Genetically Weak Fish, often over breeding or exposure to poor conditions such as with "feeder goldfish" can set up a fish for an opportunistic Columnaris infection. Sadly with genetically weak fish or fish exposed to poor conditions that permanently damage internal organs often NEVER recover from Columnaris, even with the best efforts.
From my experience and speaking with others in my profession, Crown Tail Bettas seem to be especially susceptible to fatal Columnaris infections.

The more steps you follow in this article, INCLUDING the use of a TRUE UV Sterilizer, the lower your chance of opportunistic disease outbreaks such as Columnaris (or Saprolegnia/Fungus).

For the previous stated water parameters, water changes are often very helpful (although watch cross contamination if you have more than one aquarium).

Please note that Anabantids (such as Gourami and bettas) seem to be especially susceptible to this disease, which is good reason to practice good cleaning practices with these fish even though they have the ability to get oxygen from the air.
Wonder Shells are great to use in Betta bowls as they add needed electrolytes and calcium and improve water quality between cleanings.

Product Resources:
*Wonder Shells; Unique Version from AAP

For further reading about Columnaris, please read these outside resources/references:
*Columnaris in tilapia; Use of Triple Sulfa for treatment
*Columnaris disease in fish: Including the affect of Calcium in the water upon effecting a cure (www.ncbi)
*https://www.aces.edu/dept/fisheries/aquaculture/pdf/479bfs.pdf
*Flavobacterium columnare / Myxobolus tilapiae Concurrent Infection in the Earthen Pond Reared Nile Tilapia (Oreochromis niloticus) during the Early Summer
*Influence of water quality and temperature on adhesion of high and low virulence Flavobacterium columnare
*Decostere, A., Haesebrouck, F., Turnbull, J. F., (1999), Journal of Fish Diseases, 22:1; 1 – 12

Section Two: SAPROLEGNIA (Fungus):

Saprolegnia (often classified as a mold; from the Genus “Saprolegnia”) is often confused with Columnaris and for good reasons, they can often be similar in appearance. This similar appearance is why I combined these two unrelated pathogens into this article.
Close inspection though, will reveal that a fish with Saprolegnia will have hair like growth structures similar to what you might find outside growing on a decaying piece of wood in the forest. This is what differentiates Saprolegnia (referred to as fungus) from Columnaris as you will not see the thin hair like structures upon fish with Columnaris (think "mold").
(Please click picture to enlarge)

Another consideration in differentiating Fungus (Saprolegnia) from Columnaris is that Saprolegnia & fungi often grow on dead tissue, UNLIKE Columnaris which MUST have living tissue to live on.
This is an important distinction, since it is often found on dying or dead tissue of a live fish, as well as the remains of a decomposing fish, shrimp, etc.
Another noteworthy distinction is that Saprolegnia is generally a more slowly progressing disease than Columnaris (& in fact I have yet to witness a quick or especially sudden die off from Saprolegnia in my 1000s of contracted aquariums)

One more consideration for the identification of Saprolegnia/fungi is that out breaks often occur in an aquarium/pond with large amounts of decaying organic matter, with low pH, and poor circulation in the area of decay. Sometimes this even occurs in dead spots in filters such as canister filters that are not cleaned often or in under gravel filters, especially the tubular under gravel filters.
What is also noteworthy is that an outbreak of Saprolegnia can also allow opportunistic bacteria a chance to infect fish, so then you have a double problem.

Saprolegnia is not a true fungus (fungus are from the Kingdom “Fungi” such as Oomycetes), while Saprolegnia are from the Kingdom “Protoctista” which is a catch all Kingdom for the multicellular organisms which don't fit into the Animal, Plant, or Fungus Kingdom. This includes molds, green algae, red algae and more.
Please Read Reference #1 at the end of this article, as this is an important definition that so many aquarium website information articles on this subject get wrong.

If you have ever seen a piece of fish food left in the aquarium and was covered in what looks like cotton, those are all fungus filaments doing their job of breaking down organics, and although they are a natural part of the aquatic environment, an overabundance of Saprolegnia (Fungus) caused by decaying matter (especially in new aquariums) can result with the Saprolegnia to start trying to break down your living fish and can also appear as cottony growths on the fish as well.
The picture to the left is a double close-up of a fish tail with Saprolegnia/Fungus, with inner picture a multiple magnification of how the Saprolegnia “mold” looks

Saprolegnia will often get started if there is a large amount of decomposition of nitrogenous organic material such as dead fish left in the aquarium or large amounts of high protein fish food such as krill/shrimp. Injured fish with open sores will amplify this potential problem.
This is why I generally recommend against using raw shrimp cycling method recently re-popularized on the internet by a few websites and some forums such as Yahoo Answers. I recommend against the use of raw shrimp for seeding an aquariums nitrogen cycle as this can result (as per my own studies) in Saprolegnia getting to strong a hold in a new aquarium.

While the raw shrimp or similar cycling methods have their risks for allowing a foothold for a Saprolegnia outbreak, this does not translate to dried or prepared food unless it has an outward growth of "mold" on it, and even then based on my experience, it would be just like cheese in that removing the mold, removes the threat.

Please read further about the lifecycle of Saprolegnia zoospores to also explain the risks, as well as the references.

Further Reference: The Aquarium Nitrogen Cycle; Raw Shrimp Cycling

Treatment

Sometimes treatment of Fungus/Saprolegnia is somewhat similar to Columnaris, although Saprolegnia responds well to these chemical remedies that are not generally effective for Columnaris (as well as a few antibiotic/organic remedies):

• Acriflavin for mild to moderate Saprolegnia infections (AAP Super Velvet Plus is primarily Acriflavin)
  
  Acriflavin can be combined with Malachite Green (Victoria Green), or Triple Sulfa for moderate to severe infections.
  "PolyGuard" can be a strong fungal/saprolegnia treatment. It contains both Acriflavin and Malachite Green as well as Sulfathiazole (which can also be helpful for treatment of fungus/saprolegnia, especially when used in this combination).
  
  HOWEVER the strongest available treatment anywhere for Fungus/Saprolegnia treatment is AAP Super Fungus Plus which combines a pharmaceutical grade cocktail of Sulfamethazine, Sulfadiazine, Malachite Green, Copper Sulfate, and NaCl
  
  Product Resources:
  *AAP Super Fungus Plus
  *AAP PolyGuard


• A direct swab with Merbromin (AAP Wound Control) directly on the fungal/Saprolegnia lesions (or Methylene Blue in mild cases) is often a good place to start.
  If after a couple days the swab is ineffective, this swab could be stepped more to Potassium Permanganate.
  
  Further Reference for Swabs:
  Fish Baths; Dips, Swabbing (Swabs), etc.
  
  Product Resources:
  *Wound Control (Merbromin) from AAP
  *AAP MethyBlu Premium Concentrated Methylene Blue (recommended version)
  *Methylene Blue from AAP


• Oxidizers such as Potassium Permanganate or stabilized oxygen chlorine (Maracyn-oxy, aka Maroxy).
  Maracyn-Oxy is generally tank safe in established aquariums with a healthy Redox balance and can be effective in mild all the way to severe infections.
  Potassium Permanganate is best used in a hospital tank, bath or 50% diluted swab (more about PP in the next bulleted section)
  
  Product Resources:
  *Clear Water Potassium Permanganate
  *Maracyn-Oxy from AAP
  
  More about: Aquarium Redox


• Methylene Blue can be effective (although by itself is best used in a bath) or Methylene Blue combined with Nirofuarzone & Sulfas can be another effective treatment. The product AAP Bettamax contains sulfa, Methylene Blue, & nitrofurazone
  Product Resource: AAP Bettamax


• I recommend in most moderate to severe Saprolegnia/fungus infections a Medicated Bath using Methylene Blue OR Potassium Permanganate (not mixed).
  Methylene Blue can be combined with Nitrofurazone (Furan 2) for increased effectiveness (but do not combine Potassium Permanganate with anything other than sodium chloride).
  
  Potassium Permanganate can also be used as a swab in mild isolated cases of Saprolegnia/Fungus then as a bath for serious cases.
  This bath can also be helpful even in mild cases to increase the chances of success of many mild to moderate treatments such as Pimafix or Kordon Rid Fungus.
  Please read this article for more about fish baths: Fish Baths, Swabs, Dips


• Malachite Green is an often effective treatment for Saprolegnia.
  MG based treatments such as Medicated Wonder Shells, ParaGuard or Suepr Ich Plus can often be very effective for treatment of Saprolegnia assuming the cause is removed.
  
  Medicated Wonder Shells in particular, while more of a follow up for Columnaris, are an excellent initial in-tank or hospital tank treatment for Fungus/Saprolegnia, especially when combined with swabs, and fish baths or in difficult cases where multiple pathogens are present combined with TRiple Sulfa or a Kanplex/Furan 2 combo.
  This product combines several key fungus fighting ingredients along with mineral Cations essential for helping the fish own immune system fight the infection.
  
  AAP ParaGuard & AAP Super Ich Plus both also contain Malachite Green along with Formalin for ParaGuard and Quinine Hydrochloride for Super Ich Plus.
  While Formalin is considered by some to be a useful treatment for Saprolegnia, my experience has shown otherwise. However both these products can and do work, if only for the MG they contain.
  
  Product Resources:
  *Medicated Wonder Shells; ONLY at AAP
  *AAP ParaGuard; Fungus, Saprolegnia Treatment
  *AAP Super Ich Plus


• Organic Remedies such as Pimafix or Kordon Herbal Ich Attack (AKA Rid Fungus) are often successful in mild to moderate infections.
  
  Product Resources:
  *Pimafix; at AAP
  *Herbal Ich Attack for Fungus too


• Antimicrobials such as Triple Sulfa also works reasonably well for Saprolegnia (fish fungus).
  Product Resource: Triple Sulfa; from AAP


• For very difficult cases of Saprolegnia (especially when parasites are also suspected/involved), a strong cocktail of AAP Super Ich Plus and Triple Sulfa OR Furan 2 may prove successful.
  
  Product Resources:
  *ParaGuard at AAP
  *Furan 2, Nitrofurazone at AAP

Please note that many of the above remedies can be combined for more strength, however others cannot, such as the oxidizers (Potassium Permanganate or stabilized oxygen chlorine).
Medicated Wonder Shells have several ingredients combined (Malachite Green and Acriflavin to name two) but is not as strong for serious fungus/Saprolegnia outbreaks (since these are not combined at full strength in Med. Wonder Shells) as combining other full treatments such as ParaGuard and Triple Sulfa or Acriflavin.

Salt, dips, and baths are also effective (in serious cases essential) as part of a Saprolegnia treatment.
I would use plain salt (non iodized) or even; "SeaChem Cichlid Salt" which is a balanced salt with other essential elements necessary for most freshwater fish (not just cichlids as the name implies).
As noted earlier, a Methylene Blue or Potassium Permanganate bath used at double tank strength for 30 minutes twice per day with the bath water disposed of afterwards is also very useful for Saprolegnia (Fungus) treatment (generally Potassium Permanganate is more effective for Saprolegnia).
Product Resource: Cichlid Salt; A Balanced Mineral Salt from AAP

However treatments often useful for Columnaris such as Kanamycin are less effective for Saprolegnia/Fungus.
This said, I disagree with some statements I have read about the use of antibiotics for Saprolegnia stating that these should not be used over concern for the nitrifying bacteria; these statements are based on gram positive bacteria such as Erythromycin which can and will harm your nitrifying bacteria, however the antibiotics which are effective for Saprolegnia and Columnaris are gram negative and would take over use to destroy you bio filter bed.

As for Erythromycin, I have read many fish keeping articles (especially on Betta forums) where Erythromycin (aka Maracyn) is recommended for Fungus (Saprolegnia); This is simply WRONG! While Fungus is not a bacteria and so cannot be labeled as either gram positive or gram negative; the fact is gram positive medications do not treat true fungal/saprolegnia infections and even if this is a misdiagnosis with Columnaris, this is still incorrect since Columnaris is gram negative. Sadly this misinformation is cut and paste around the Internet resulting in many needless fish deaths based on my experience and emails!!

Saprolegnia (fungus) can be even more opportunistic in poor water with stressed or injured fish than many bacterial infections such as Columnaris, so healthy water conditions are even more important for cure (& prevention) and if water conditions are poor, all the medications in world may not affect a cure!

The obvious 0 ammonia/nitrites are important but so is the often forgotten GH and a stable pH (provided by a proper KH for the fish kept). Without adequate calcium (found in GH) your cure will be difficult to achieve. Medicated or regular Wonder Shells may help in this area.
Reference: Aquarium Chemistry; GH, KH, pH, Calcium, Electrolytes for a healthy aquarium

Also important is a clean tank without organic mulm buildup, so make sure there is NO decomposing organic debris which can by itself bring on a Saprolegnia infection, in fact I have documented this which is why I generally recommend against using raw shrimp to start your nitrogen cycle.
Please see this well researched article for more about the Aquarium Nitrogen Cycle:
“The Aquarium (& pond) Nitrogen Cycle”.

This article about aquarium cleaning may also be useful:
“Aquarium Cleaning”

Prevention/Lifecycle of Saprolegnia

Understanding the lifecycle and Prevention of Saprolegnia is probably the best “cure”.

The lifecycle is best described this was: the asexual spore of Saprolegnia release motile, primary zoospores.
These primary zoospores are active only for a few minutes before they encyst, germinate, and release a secondary zoospore.
Secondary zoospores are more motile for a longer period of time than primary zoospores and as well are considered the main dispersion phase of Saprolegnia.
The repeated cycles of encystment and release, called "polyplanetism", allows secondary zoospores to make several attempts to locate a suitable substrate or host.

It is these Secondary zoospores which are considered the infectious spore of Saprolegnia and can reside in grave/substrate, filters, and the water column for some time until this host is found (these spores do NOT require a food source during this time as well). Repeated vacuumings and large water changes can reduce this number but not totally alleviate it unless the tank is sterilized with bleach (especially since these spores can reside anywhere in an aquarium), so denying the zoospores a host via healthy, non stressed disease resistance fish is the next step.
This is major reason why the long ago discredited "Raw Shrimp" aquarium cycling method should NOT be used!
Please click on the diagram for a better view/larger diagram of the Saprolegnia lifecycle.

Further Reference: Aquarium Nitrogen Cycle; Raw Shrimp Cycling

KEY POINTS ABOUT SAPROLEGNIA/FUNGUS FOR PREVENTION AND TREATMENT

• Make sure to vacuum out ALL decaying organic matter, especially high protein organics such as uneaten shrimp or similar. I recommend treating all wounds in fish immediately when discovered, slowly increasing pH (for fish that can tolerate a higher pH, which even Discus can thrive/breed in a pH above 7.0) and finally maintain proper electrolytes(such as calcium cations) in your aquarium as well as the possible addition of salt when wounds are discovered for healthy osmoregulation.
  Reference: Aquarium Chemistry; Electrolytes


• With Saprolegnia, the temperature tolerance by the Saprolegniasis is quite wide; 3C to 33C (37F to 91F).
  However, sudden changes in temperature can make fish vulnerable to a Saprolegnia infection. So unlike with Colummnaris where an ideal temperature of 75F is best for cure, maintaining a not too hot, not too cold aquarium/pond that has STABLE temperatures is what is important!


• It is noteworthy that Saprolegnia thrive in lower pH water, especially under 6.0, although any water under 7.2 provides a habitat that can support strong Saprolegnia growth. With this in mind, keeping slightly more alkaline water is both good treatment and prevention for Saprolegnia.


• As to correct levels of electrolytes such as calcium (which is all too often missed by many anecdotal aquarium articles), is that CORRECT mineralization induces a healthy mucous layer on the fish epidermis which is so VERY important in fish resistance to Saprolegnia infections, in fact this quote from Oregon Sate University says it best:
  “Willoughby (1989) determined that fish have 3 types of defenses against Saprolegnia.
  
  • First, the physical removal of attached spores by the renewal of mucous.
  • Second, a morphogen in the mucous inhibited the growth of mycelium but not killing it.
  • And third, a cellular response in the mucous is directed at growing mycelium.
  
  Therefore, the mucous acts as a primary physical barrier (Bruno and Wood, 1999; Pickering, 1994), by continuous replenishment of the mucous layer (Pickering and Willoughby, 1982), although not for complete, i.e., 100%, removal of fungal spores (Murphy, 1981; Willoughby and Pickering, 1977).
  However, a fish having an intact epidermis is probably the best defense against saprolegniasis (Hatai and Hoshiai, 1994; Pickering, 1994).”
  
  This why I cannot emphasize more the need for correct mineralization (products such as Wonder Shells are excellent for this), the use of salt when needed, possibly a higher pH or KH and over all good water quality that includes a healthy Redox Balance.
  See also Aquarium/Pond Chemistry


• Saprolgenia is an opportunistic infection, often the result of water conditions as already noted. However Saprolegnia/Fungus is also common as the result of injury, whether it be fighting or simply from the fish striking and object in the aquarium or the aquarium sides itself (this is especially common with larger fish, fish in "too small an aquarium", or a fish that gets "spooked")


• Keep your filter flowing correctly.
  Allowing organic debris, uneaten fish food, etc. to build up in canister filters, poor flow areas of wet/dry filters and under gravel filters, etc. can result in Saprolegnia issues.
  Sometimes outright removal of filters that are the root cause can improve ongoing Saprolegnia issues. I have witnessed this first hand with the old tubular style of under gravel filters that were popular in the 1970s and recently have been sold again.


• As with Columnaris, the use of a correctly set up, well designed UV Sterilizer (such as the Premium TMC Vecton or Advantage UV Sterilizer) can help with Saprolegnia (Fungus) prevention. However a sterilizer can only help with spores in the water column, not growths in the gravel, under decor, in filters etc. A good UV Sterilizer can also indirectly help by improving Redox balance and then in turn fish immunity.
  Reference: UV Sterilization; Facts & Information
  
  Product Resource: TMC Vecton or Advantage High Dwell Time UV Sterilizers

For further reading about Saprolegnia, please read these outside resources:

(1) "Kingdom Protoctista is defined by exclusion: its members are neither animals (which develop from a blastula), plants (which develop from an embryo), fungi (which lack undulipodia and develop from spores), nor prokaryotes. They comprise the eukaryotic microorganisms and their immediate descendants: all nucleated algae (including the sea-weeds), undulipodiated (flagellated) water molds, the slime molds and slime nets, and the protozoa. Protoctist cells have nuclei and other characteristically eukaryotic properties; most have aerobiosis and respiration in mitochondria and 9+2 undulipodia at some stage of the life cycle."
From: http://species-identification.org/species.php?species_group=dinoflagellates&menuentry=groepen
(2) Neish, G.A., and Hughes, G.C. 1980. Diseases of fishes, Book 6, Fungal Diseases of Fishes. T.W.F. Publications, Neptune, New Jersey. 159 p.
(3) “The Occurrence of Watermolds with respect of pH of Water ”