Bacterial Infections Vs Fungal Tail Rot

Discussion in 'Freshwater Fish Disease' started by Whitewolf, Apr 22, 2017.

  1. WhitewolfWell Known MemberMember

    I am writing this post in hopes that people will give it a read and understand the diffrent types of bacterial and funga ailments that happen quite often to stressed or weak fish in our aquariums. Hopefully, this will clear up alot of confusion among new hobbyist, and hopefully a moderator can make it a sticky, and we can hotlink it. I am gonna keep it short and sweet, to the point, so people dont have to read a huge article. I do not know it all, but can clear up some areas about "fungus" and bacterial infecion that alot of newcomers don't understand.

    The first problem we run into alot is fungal tail rot, or that of a wound or area of skin that has been damaged, due to saprolegnia, or water mould. This fungus or mould is naturally present in all declorinated water, and naturally breaks down leftover food or other organic matter. This will not and should never attack a healthy fish, it does not simply "grow" on a fish. Please understand this, this is the main point of my thread.
    What happens when people see a saprolegnia infection on a fish, like say a rotting tail line, they think it is a "fungus" which it is, but it is always Secondary to bacteria. Fungus, water mould, whatever you want to call it, only breaks down, lives on or eats Dead material. Therefore we can say with confidence that your fish dosent have a "fungus" problem, but rater a bacterial infection. I actually will expalin the two in opposite order, first the bacterial kind that spreads and kills entire tanks of fish in summary, then the fungal tail rotting of dead tissue.

    There are many diffrent types of bacteria that can get a foothold on a fishes tail fin, the cadual. These are not always the bad kind that can spread, so its best just to keep an eye on the fish and keep the water clean and good parameters.
    Then there are the bacterial infections.......
    The types that spread and can kill a fish are the ones we are concerned about, and the 3 most common genus of these rot causing bacteria are:
    Aeromonas = Aeromonas - Wikipedia
    Pseudomonas = Pseudomonas - Wikipedia
    Columnaris = Columnaris - Wikipedia

    The easiest way to get rid of these types of bacterial infections is with an antibiotic, specifically a Gram-Negative antibiotic.
    Tri-sulfa can be found at petsmart, and can be put in the water column and will work effectively.
    Kanamycin "kanaplex" is another good antibiotic that works well in the water column, and can be found at most Fish only stores.
    There are other types of antibiotics that will work, but you also should understand that many do not dissolve properly in water, especially Hard water, and are not well absorbed thru the fishes skin, there for antibiotics such as Maracyn-2 "Minocycline" and Terramycin "Oxtetracycline" are broad spectrum Gram + and -, are very good antibiotics to use, but must be fed to the fish in the form or pre-made flake or pellet, which can be found online. This ovbiously would not work for a fish that is not eating, but it does work very well to go directly into the fishes body.

    Then there are the fish with large colorful fins. Fish are bread this way to make for a pretty animal that sales easy, but it is these larger than nature intended fins that cause problems. Many times, a fish such as a Fancy guppy, Fancy goldfish, or beta will have very large fins, especially the cadual (tail) fin.
    As with all organic matter, there needs to be a blood supply, even to cartiladge such as our ears, in order for the organic material to live. When these fins are much larger than nature intended, there is poor blood supply to these areas. Minor problems such as stress, fighting, high nitrates or bioload, or large water changes can cause damage to these fins. Bacteria will take hold and then the fungus follows leading to a rotting often white colored decaying edge of the fins. The best way to cure something like this is with a medication in a hospital tank, or to simply increase water changes (frequency, not size)
    This is where alot of people claim to cure tail rot with "clean water" and advise others to do the same, but the new hobbyist may not have a natural fungal breakdown of the fins, but rater a bacterial infection caused by one of the three main genus of bacteria, and these types of infections can take hold and spread and eventually kill fish or entire tanks, the dreaded columnaris outbreak.
    I am not going to speculate on what you should do too much for minor fungal tail rot, because many times it will simply go away on its own. I do not belive in the use of messy chemicals, its bad for the environment and can stain the aquaria and wipe out good bacteria.
    If you really want to cure a guppy, goldfish or beta or any fish with some minor fungal tail rot, i reccomend a product such as methylene blue, formalin, or acriflavine, used in a hospital tank. Furan 2 "nitrofurazone" can also be used.
    These products are anteseptic agents, and can be quite nasty on a tanks biological filtration, so should be used in a small ten gallon hospital tank for an extended bath period of 1-3 days. Turn the heat up to 78-82 degrees, add some aquarium salt if you wish, and do not feed. A simple airstone and heater with light should be used. Start with half aquarium water and half freshwater, and i reccomend a bare bottom tank.
    There are products like melafix and primafix that can be used sucessfully, but if you wish to go this route i suggest buying reguar tea tree oil from a specialty shop in bulk, look up the ingredients to these two products, and proper dosing, and mix your own and store the rest. There is no reason to spend 8 or 9 dollars on a small bottle.

    The main point im trying to get across is this, fungus does not simply live on and infect/eat or kill a healthy fish. A fish has a slimecoat that protects it from things like fungi/mould. Wounds can get infected, parasites can cause slime coat damage (costia) that then gets fungi, and tail fins can rot. It is important to understand the diffrence between cases like this, and a acute bacterial infection. The easy way to tell is if the rot seems to spread to dorsal, pectoral fins, or the body of the fish, then it likely is a infection resulting from pathogenic bacteria, and needs to be treated with antibiotics.
    Last edited: Apr 22, 2017
  2. CindiLFishlore LegendMember

    Good information! Part of the mis-information itself is from the marketing labels on the medicine. Wish they'd correct those.

    Would just like to correct/clarify a few things if thats ok? And add some additional medicine information, maybe it can be incorporated into your post before it gets stickied.

    You talk about the tail fin, but really this can happen to any of the fins, especially in the case of long finned fish like those you mentioned, male bettas, fancy goldfish and fancy guppies. Just want people to understand it can be any of the fins.

    One way to tell the difference between the type of disease (fungus vs bacterial) is that bacterial infections will often have a fuzzy or cottony look to them. "True" fungus will look like little individual hairs.

    Best to not turn up heat with any of these infections, the advice is actually to turn heat down a couple degrees as the bacteria thrive and multiply more rapidly in warmer temperatures. Some bacteria like flavobacterium in columnaris especially thrive in temperatures above 78.

    I think nitrofurazone is often a good first choice along with kanaplex and I'd use before tri-sulfa. I know you think I'm partial to this one, ha ha and I am but that is because it works and is so effective on external fin and body issues like these bacterial diseases. Also it is a gram negative antibiotic not an antiseptic like the others mentioned.
    I'll mention some name brands people can find it in: API Furan-2 or Tetra Fungus Guard, Hikari Bifuran or Jungle Fungus Clear tabs (this one is at Walmart).

    Maracyn-2 is a gram negative antibiotic and can sometimes be used in place of Kanaplex if that can't be found. I have used it successfully along with nitrofurazone for Columnaris.

    Lastly, antiseptic agents which are often also used for parasites are sometimes effective on bacterial infections but would be my second choice for bacterial infections. They are good first choices for saprolegnia growing on damaged or open wounds (like ulcers) or sores and as general antiseptic agents. These include malachite green and acriflavine found in API Fungus Cure and also many ich remedies, and the others you mentioned such as methylene blue, can be found in Kordon's product. Seachem Stress Guard and Paraguard both have malachite green in them, though Stress Guard has a smaller concentration.
    Lastly Hikari Betta Revive has a great triple combination of malachite green, methylene blue and neomycin. Of all of these the only one that will really knock out your bio-filter is methylene blue and should never be used in the main tank but instead in a hospital tank or as a 30-60 minute bath at double dose outside the tank.
    Last edited: Apr 22, 2017
  3. stella1979ModeratorModerator Member

    Thank You! Subbed and bookmarked!!!
  4. WhitewolfWell Known MemberMember

    Glad you liked my post!
    People have asked me to post something like this recently to maybe make it a sticky or hotlink to explain to people the diffrence. I dont really care if it becomes a sticky or not, i could still link it to people rather than repeat myself on a daily basis whenever a fish has a bacterial infection. Its up to them weather they want to read and understand it all or not. lol I Had alot of coffee this early morning and just decided to type it up, get it over with.
    I agree, the problem is with new hobbyist who would rather listen to a pet store employee or what it says on the box, rather than knowledgeble people on forums. This is a good forum for good advice, but for whatever reason chain pet store employees just dont give sound advice, and the labels are misleading, agree 100 percent and thats why i typed this up.
    The only thing im gonna counter you with is that for the fungal, mold aspect, I would actually raise the heat because mold does better in lower temperatures, like it would grow in a cool damp place in nature. I know there are reasons to lower the heat when it is an actual bacterial infection, yet i have cured columnaris easily, with just oxytetracylcine feed 3x a day, in an unheated room in the summertime when the temp during the day rose to 88F with minimal loss and a crowded ten gallon tank. Not to sound like a know it all or fish disease expert, but temp dosent seem to really matter that much.... (ofc up for debate)

    I remember when i was new i read to lower the heat or just unplug the heater during a bacterial or F. columnaris outbreak, but it just seems to put the fish's metabolism (and also their immune system) into sleep mode and didnt really slow the disease much. That is where i disagree, but its only a personal preference of mine. Its probably better to just leave the heat where it is suppose to be at anyways.

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