Category Archives: Fungus / Ringworm

Treating Finrot and Mouthrot In Bettas

Treating Finrot and Mouthrot In Bettas

Finrot and mouthrot are bacterial or fungal infections that occur to Bettas or Siamese Fighting Fish when they’re worn down by chilling, poor water quality and, or parasites.

By themselves without parasites, in good warm water, Bettas don’t get finrot or mouthrot. (Although you can BUY stressed fish that soon break with it.)

Treating Finrot and Mouthrot In Bettas
Treating Finrot and Mouthrot In Bettas

So, what to know when Treating Finrot and Mouthrot In Bettas?

This video protocol steps you through Treating Finrot and Mouthrot In Bettas with specifics and it’s successful.

Saprolegnia (or SAP) is a Freshwater Fungus of Pond and Aquarium Fish

Saprolegnia – Water Fungus

Written by R.E. Carlson

aquarium fish and fungusLike all fresh water environments, koi and goldfish ponds are living ecosystems. They contain plants, algae, invertebrates, protozoa, bacteria and molds or fungi. Many of the life forms in our ponds are dependent upon each other. This is known as symbiosis (living together). An extreme form of symbiosis is parasitism, where one life form lives at the expense of another. One of the more common forms of parasitism in our ponds is saprolegnia or water fungus. For the average ponder, great zoological detail about saprolegnia is not required to understand what it is, what it does and how to treat the pond and fish if it becomes a problem, therefore not much detail on the zoology of saprolegnia is offered here: just good-to-know information on how to identify and treat it as well as some tips to help prevent it from affecting your fish.

What Saprolegnia Is

Saprolegnia (or sap) is a freshwater fungus which simply means it lives in fresh water environments and needs water to grow and reproduce. Sap can also be found in brackish water and moist soil. It is often referred to as a “cold water” fungus as it flourishes in colder water, but it lives well in a wide range of water temperatures extending from 37 deg F to 91 deg F (3 to 31 deg C). While it has been described also as a “mold”, sap is a genus of fungus, with the difference being a “mold” is a mass of fungi.
Under the microscope, sap is composed of filaments that tend to have spherical ends. It is these spherical ends that house the zoospores, or the “seeds” of sap, that allow it to proliferate and spread. The filaments are called hyphae and give sap its cotton-like appearance. It is the hyphae, or more exactly, the hooked, foot-end of the hyphae, which penetrate the tissue of the fish as they seek nutrients. In the lower-power micrograph below, you can see the hyphae with the spherical ends. With a 400x microscope, the structure will look basically the same.

fungal infections in fishIn the water, sap looks like fluffy cotton; however, out of the water it appears to be a matted mess of slime. Sap starts out either white or grey in color. The grey appearance also may indicate the presence of bacteria growing with sap’s structure. Over a short period of time, sap may turn brown or green as organic particles in the water (such as algae) adhere to the filaments. Note the picture below. This is a classic presentation of sap that has invaded a bacterial infection of the dorsal fin area of a koi. The green color is actually embedded algae particles within the sap’s filaments.

By appearance, sap can be easily confused with epistylus, a freshwater parasite that presents as a white cottony substance growing on the skin of the fish. Epistylus does not gather organic particles and will remain white. Confirmation of epistylus versus sap should be done with a microscope. The following is a microscope shot of epistylus at 400x:
The favorite food of sap is dead organic tissue. We can usually see evidence of sap on dead and dying fish, live and dead fish eggs and even food left in the water so long that it has begun to rot. Typically we see infertile koi eggs being infected first with the fungus then it spreads to kill live, fertile eggs. Infected eggs have a typical fluffy cotton wool-like covering. Sap also likes to feast on exposed and decaying tissue caused by bacterial infections, such as ulcers. It is most prevalent on the head and fins of the fish as these are the areas that offer the least amount of natural resistance provided by the mucous coat.

Primary and Secondary Invader

Typically we think of sap as a “secondary” invader. This means that something else has violated the integrity of the fish’s skin allowing bacteria to enter and provide direct tissue access for the sap hyphae to embed themselves. In treating sap, it is imperative to treat BOTH the sap and the underlying primary cause. This will be discussed in more detail in the treatment section below.
However, sap can also be a primary invader under the right conditions and this is where it gets the reputation as a “cold water” fungus. We all know that cold water conditions, including dramatic temperature changes, cause great stress on the fish and suppress the fish’s natural immune system. As stated above, sap flourishes in colder water by producing and releasing increased zoospore counts into the water. The combination of stress, suppressed immune systems, and increased spore counts give sap the ability to cause major problems in colder water. Sap infections are commonly the cause of “winter kill.”
The following is a list of conditions that support the spread of sap:

  1. Overcrowding – stress and too many organics in too little water
  2. Handling – stress and removal of the mucous coat on the fish
  3. Epidermal integrity – open wounds that provide direct access to tissue
  4. Parasites and pathogens – parasites cause wounds that allow pathogens (like bacteria) to enter thetissue thus giving sap a change to take hold and stress
  5. Pollution – stress and reduced water quality
  6. Spawning – stress and physical damage
  7. Water quality – stress and reduced physiological conditions
  8. Water temperature changes – stress.

Obviously the underlying theme in the above list is “stress” and this is the one thing that we need to guard against first and foremost to keep our fish healthy. In healthy conditions, our fish have some natural protection against sap with the mucous layer being the most effective first line of defense. The mucous layer provides the ability to reject a sap attack by sloughing off a layer of mucous and sending the sap with it. The mucous coat also provides a natural fungicide at the cell-level. So you can see that improper handling or any activity that reduces the mucous coat offers an increased opportunity for sap to take hold.

Death by SAP

An increased morbidity of fish caused by sap can be traced to three major things:

  1. Low water temperatures
  2. High concentrations of sap zoospores
  3. Mechanical stress

fungal infections in fishWe know that sap attacks fish weakened by any of the above and the suppressed nature of the immune system under cold water or high stress conditions leaves the fish mostly defenseless. However, what kills the fish in a sap attack is a condition known as hemodilution. By definition, hemodilution is “a decreased concentration (as after hemorrhage) of cells and solids in the blood resulting from gain of fluid from the tissues.” … this causes the blood to loose electrolytes (blood salts) and make it less than life-supporting. Then as the sap hyphae penetrate the tissue layers of the skin, water begins to enter the fish thereby further diluting the fish’s blood salts. This explains why fish grossly affected by sap appear lethargic and often lose their equilibrium.

Once it has (literally!) taken root, sap can spread rapidly over the surface tissue of the fish. While it is rare that sap will penetrate deep into tissue layers, even superficial damage to the fish’s initial tissue layers (and particularly the gills) can be deadly. Obviously, the more wide-spread the sap infection becomes, the higher the rate of hemodilution and greater chance that the fish will not recover. Therefore, managing the sap infection quickly becomes the key to saving the fish.

Protection and Treatment

Obviously, the best “cure” for sap is prevention. As mentioned, sap is present in every pond and has its place in the order of life in the pond’s ecology. It really only becomes a problem when something has gone wrong with the fish and/or the pond or a condition such as cold water suppresses the fish’s immune system. Some of the steps we can take to reduce sap’s effectiveness include:

  1. Providing a stress-free environment (which starts with excellent water quality)
  2. The active reduction of organics in the pond (good mechanical filtration and a balanced ecology). This also will reduce natural aeromonas bacteria counts
  3. The quick removal of dead and dying fish and excess food
  4. Proper handling (which starts with as little handling as possible)
  5. Elimination of parasites
  6. Increased water flow during warmer conditions

But no matter how hard we try, and especially for those ponds located in areas subject to cold water situations and/or rapid water temperature changes, sap is always a possibility. Except as noted above, there are no reasonable preventive measures, including the use of anti-fungal products as they just do not work effectively against sap. Therefore, we must be prepared to diagnose and treat sap as soon as we see it and here are some treatment recommendations:

Malachite Green (MG): Hands down, this is the best treatment for all fungal problems, including sap. MG baths and dips work_ exceptionally well and one treatment will usually solve the problem (assuming any contributing causes are corrected as well). There are certain cautions that go with using MG, such as use only in cooler, well aerated water, so read the label carefully for instructions and precautions. MG is not recommended as a pond-wide treatment for sap as the concentration levels needed to kill off sap are too high for a pond-wide treatment to be effective. Such products as ProForm C, a Malachite Green-formalin combination can help reduce the incidence of sap and parasites in the water, but because the sap hyphae may be deeply embedded, the stronger dip or bath method is recommended. Caution: Malachite green is carcinogenic and has been banned for use on food fish. Use MG with great care.

Salt: This is a distant “second best” treatment to MG. Salt in the 0.6 to 1.0% range for 30 minutes or less can help eliminate sap. The caution with this approach is that the higher the salt level, the more stress the fish will endure so check carefully on the stability of your fish prior to performing a high-level salt bath.

Formalin: Formalin is mentioned as a treatment for sap however, generally speaking, formalin is ineffective against most molds and fungi. Like MG and salt, formalin comes with its own precautions, including limiting its use in warm water, where low oxygen situations may develop. Handle formalin with care, its toxicity is well known. Diluted versions of formalin products, such ProForm C offer a nice one-two punch where MG takes out the sap and formalin gets the parasites. It is not recommended to use formalin against open wounds because of the harmful effect of formalin on exposed tissue and cell structures.

Potassium Permanganate: (Hard to find anymore) In the right hands, PP is one of the better treatments for sap. PP treatments at 4PPM (4g/1000 litres) will eliminate most of the sap but for deeply embedded sap hyphae, further surface treatments using a PP paste may be required. The down side of PP, of course, is the inherent danger of using it at all. It is not recommended for those inexperienced with its use.

Treating a sap-affected fish requires that the wound site be tended completely. As mentioned, sap is generally a secondary invader; this means something else went wrong to allow the sap to take hold, like a parasite attack or another wound that opened the tissue. So, when treating a sap-affected fish, first eliminate the sap from the surface of the fish and then treat the actual wound site, which is most likely starting to look like an ulcer. Depending on the extent of the underlying wound, injectable medications may be required and the assistance of a veterinarian sought. If you suspect that cold water has allowed sap to become a primary invader, attention to the surface tissue of the affected fish is still required as the sap hyphae penetrates the tissue and can allow bacteria to enter the wound site.

aquarium fish and fungusMuch has been said regarding the importance of using a microscope in the koi hobby. A microscope with a range up to 400x (eg 40X objective and 10X eyepiece) is an invaluable tool for diagnosing problems with our fish as well as viewing almost the entire spectrum of the ecology of our ponds from algae to parasites to the larvae of insects. At 200x, the filament structure of sap is easily to see and at 400x, the hyphae and spherical ends of sap are clearly discernible. Also, at 200x the movement of most parasites can be easily seen and at 400x, virtually all of the parasites that routinely inhabit our ponds can be detected and identified.

As you can see, sap is one of the major potential problems that we have to be prepared to deal with. Since sap is always present in our ponds, it is imperative to take as many preventative measures as possible to keep it from affecting the fish. But even the best pond keepers will eventually get a sap outbreak and when this happens, treatment must be quick and complete as this is not a problem that will just go away all by itself.
RE Carlson

Symptoms and Control of Branchiomyces Fungus, BGD in Koi and Pond Fish

This is a warmwater gill fungus. I’ve had this in a collection of my own fish, one winter when the fish room was very warm, but the lack of sunlight, and high nitrates were stressing the fish. Then the gill fungus hit. If I had been replacing water all the time, it wouldn’t have happened. 

Branchiomyces in Koi

Written by Dr Erik Johnson

Branchiomyces is an aggressive gill fungus. It will kill fish by adulterating their gill tissue. The fungus compromises vascular
supply to gill tissue and the affected areas die and slough out leaving gaping sockets in the gill arches. The fungus relies on
high organic loads, high Nitrate levels, crowding, and HEAT to activate, and kill fish.

  • Hot water organism
  • Requires high organics
  • Controlled wth Formalin

Recognizing Branchiomyces

Fish will linger at surface and die in three days, sometimes one by one, starting with the smallest fish.
When you examine the fish, you will notice the gills are eroded and there are necrotic sections in the gill tissues, grossly.
Special stains will show starlike fungal elements, but this is not critical because treatment is simple.

Limiting Losses from Branchiomyces:

  • Cool water will slow the fungal infection down and save fish lives, it REQUIRES hot water to thrive and is most common in intensive conditions where fish are crowded, there are high organc loads and the water is WARM.
  • Cool water carries more oxygen and eases the metabolic furnace of the fish.
  • Increasing aeration WITHOUT increasing exertion to the fish (e.g. spraybars) may be life saving.
Eco Labs BSDTGAL Broad Spectrum Disease Treatment Gallon
Eco Labs BSDT GAL Broad Spectrum Disease Treatment Gallon

Controlling Branchiomyces:

Formalin is very effective. See FORMALIN
For more information on how to use the Formalin or refer to the book.
Expected results:
Amazingly, when encountered, Branchiomyces is rapidly cleared. The pond should be cleaned, organics in the filter and in the biofilm should be scrubbed or removed and the water should be cooled, which can and will be accomplished in part by the frequent water changes mandated by the Formalin treatment.
Fish will be noticeably perkier and feel better the day after the water is cooled and the Formalin is applied.
No Formalin treatment should last longer than 2 hours.

Best Regards,
“Doc Johnson”


3. Anonymous. 1973. Fish diseases and their control. FAO Aquacult. Bull. 6(1):1618. An occurrence of a Branchiomyces sanguinis infection is described in fingerling striped bass reared at a fish hatchery in Arkansas. Repeated treatment with 25 ppm formalin relieved the infection. Tilling and drying of the bottom of the affected pond prevented recurrence of the disease during the following 3 years.
49. Meyer, F. P., and J. A. Robinson. 1973. Branchiomycosis: a new fungal disease of North American fishes.
Prog. FishCult. 35:7477. Mortality of fingerling striped bass at a fish hatchery in Arkansas was attributed to a gill disease identified as “gill rot” caused by the fungus Branchiomyces sanguinis. The affected gill tissues became necrotic and were white or brownish due to impaired circulation. Often necrotic tissues sloughed off, leaving denuded areas on thegill arches. Infected fish became extremely weak, showed respiratory distress, lost their equilibrium, and died An initial pond treatment of formalin at 15 ppm, followed by applications of 25 ppm, stopped mortality. Repeated treatments were required to control the infection. The authors recommended that infected fish be destroyed and ponds sterilized before draining because branchiomycosis sometimes reappears if ponds are not thoroughly dried.
Diseases of Aquatic Organisms
DAO 31:233-238 (1997)
Branchiomyces-like infection in a cultured tilapia (Oreochromis hybrid, Cichlidae) I. Paperna1,*, M. Smirnova21Department of Animal Sciences, Faculty of Agriculture of the Hebrew University of Jerusalem, Rehovot 76100, Israel 2The Central Fish Health Laboratory, Nir David 19150, Israel *E-mail:
ABSTRACT: A Branchiomyces-like fungus was identified from histologically examined gills of juvenile red tilapia Oreochromis niloticus × O. mossambicus and green tilapia O. niloticus × O. aureus obtained from intensive fish farms in Israel. Hyphae embedded in the gill tissue contained undivided and sporulating stages. In one instance infection appeared to be subclinical, limited to one or a few loci in the gill filament and causing only localized tissue damage. In the second case, infection, which was severe and caused extensive tissue damage, was identified in fish from a stock suffering massive mortality which resulted in the loss of 85% of the pond fish.
KEY WORDS: Branchiomyces · Gills · Oreochromis hybrid ·
Cichlidae · Mortality · Aquaculture · Israel
Published in DAO Vol. 31, No. 3 (1997) on December 30 ISSN: 0171-8630. Copyright Inter-Research, Oldendorf/Luhe, 1997
Branchiomycosis (Gill rot)
A) Caused by two species Branchiomyces sanguinis and B. demigrans.
B) Primarily a problem in carp and eels.
C) Affected fish usually show respiratory distress. There is prominent gill necrosis caused by thrombosis of blood vessels in the gills. Histologically the identification of nonseptated branching hyphae with an intrahyphal eosinophilic round body (apleospores) in and around blood vessels of the gill is diagnostic.
D) The disease occurs most commonly in ponds with abundant organic matter, and high ammonia levels.
Usually warm water temperatures (20-25øC) bring about the disease.
Use of DiQuat:
Another chemical is the herbicide Diquat. It has been used at a concentration of 8.4 to 16.8 ppm of the formulated material, or 2 to 4 ppm on the basis of active ingredient (Diquat cation).
Several chemicals have been used to treat BGD in hatchery salmonids. The most widely used are quaternary ammonium compounds, such as benzalkonium chlorides, available as Hyamine 1622 (98.8% active ingredient) and Hyamine 3500 (50% active ingredient). Another compound of this type is Roccal, available in 10% or 50% concentrations. Benzalkonium chlorides are used in concentrations of 1 to 2 ppm (calculated on the basis of the active ingredient) as a 1h bath or continuous flow treatment. Caution is necessary because the margin of safety is narrow, particularly in soft water.
Another chemical is the herbicide Diquat. It has been used at a concentration of 8.4 to 16.8 ppm of the formulated material, or 2 to 4 ppm on the basis of active ingredient (Diquat cation).
None of these chemicals are approved by the U. S . Food and Drug Administration for disease control in food fishes. Efforts are under way to have chloramineT registered as a treatment for BGD. This compound was found effective for BGD when used at 8.5 ppm for I h (From 1980). In hatchery tests conducted by the National Fish Health Research Laboratory, one treatment effectively controlled BGD when it was given early in an outbreak. However, two or more treatments are required for advanced outbreaks.
When BGD, caused by C. columnaris, occurs in pondfish, external treatments for the control of columnaris disease are used.
The treatment with 8.5 ppm Diquat described above has been reported to be effective. Diquat, copper sulfate at 0.5 ppm, and potassium permanganate at 2 to 4 ppm can be added to ponds and allowed to dissipate over time. If copper sulfate or potassium permanganate are used, treatment levels may have to be adjusted, depending on water chemistry. In soft water, 0.5 ppm copper sulfate may be toxic; and if pondwater is high in organic material, potassium permanganate concentrations must be increased (Rogers 1971; Jee and Plumb 1981).
Fungal Diseases of Fish
Ruth Ellen Klinger and Ruth Francis-Floyd
Fungi are a group of organisms called heterotrophs that require living or dead matter for growth and reproduction. Unlike plants, they are incapable of manufacturing their own nutrients by photosynthesis. Fungi are present everywhere–in saltwater or fresh water, in cool or warm temperatures. In most cases, fungi serve a valuable ecological function by processing dead organic debris. However, fungi can become a problem if fish are stressed by disease, by poor environmental conditions, receive poor nutrition, or are injured. If these factors weaken the fish or damage its tissue, fungus can infest the fish. Fungi can also prevent successful hatching when it invades fish eggs.
Fungi are grouped by the morphology of various life stages. All fungi produce spores–and it is these spores which readily spread disease. The fungal spore is like a seed which is resistant to heat, drying, disinfectants and the natural defense systems of fish. The three most common fungal diseases are discussed here. They are known as Saprolegniasis, Branchiomycosis, and Ichthyophonus disease.
Branchiomyces demigrans or “Gill Rot” is caused by the fungi Branchiomyces sanguinis and Branchiomyces demigrans .
Branchiomycosis is a pervasive problem in Europe, but has been only occasionally reported by U.S. fish farms. Both species of fungi are found in fish suffering from an environmental stress, such as low pH (5.8 to 6.5), low dissolved oxygen, or a high algal bloom. Branchiomyces sp. grow at temperatures between 57° and 95°F but grow best between 77° and 90°F. The main sources of infection are the fungal spores carried in the water and detritus on pond bottoms.
Disease Signs
Branchiomyces sanguinis and B. demigrans infect the gill tissue of fish. Fish may appear lethargic and may be seen gulping air at the water surface (or piping). Gills appear striated or marbled with the pale areas representing infected and dying tissue. Gills should be examined under a microscope by a trained diagnostician for verification of the disease. Damaged gill tissue with fungal hyphae and spores will be present. As the tissue dies and falls off, the spores are released into the water and transmitted to other fish. High mortalities are often associated with this infection.
Management and Control
Avoidance is the best control for Branchiomycosis. Good management practices will create environmental conditions unacceptable for fungi growth. If the disease is present, do not transport the infected fish. Great care must be taken to prevent movement of the disease to noninfected areas. Formalin and copper sulfate have been used to help stop mortalities; however, all tanks, raceways, and aquaria must be disinfected and dried. Ponds should be dried and treated with quicklime (calcium oxide).

Ringworm in Cats: Fungal Infections Among Felines

Cat Feline Ringworm Dermatophytosis

Ringworm is very rare, and more commonly found in homes with many cats under considerable environmental stress. Chain-smoking breeders can turn out a ringworm infested cat, too.


Ringworm is a fungus not actually a worm. The fungus can infect cats, dogs, and HUMANS. Treatment can be frustrating due to the often slow disappearance of the ringworm lesions and clinical signs. If you (or a pet) have ever had Ringworm, you know what I mean.


1.Topical therapy:

This consists of creams, dips or sprays applied directly to the affected area. Treatment should be continued for one week after signs disappear.

2.Oral therapy

With widespread distribution of spots, or in a case of ringworm that is nonresponsive to topical medication, oral medication is often prescribed. IT IS VERY IMPORTANT TO GIVE THIS MEDICATION EVERY DAY AND WITH A HIGH FAT MEAL (such as tuna in oil).

3. Adjunctive therapy

A. Medium to longhaired animals should be clipped for more effective treatment.

B. A vaccine was once available that was supposed to actually hasten the clearance of the clinical signs. Marketed by Fort Dodge® Labs, it is touted as a complete ‘cure’ for Ringworm, but the results were exceptionally poor. Like a few of the vaccines available today, to be sold, they have only to prove a disease exists, the vaccine exerts ANY control and is not dangerous to the pet. That is all. I do not rely upon it as a cure.

C.Vacuum carpeting and furniture at least once weekly. The infected hairs that are shed can remain infective for ONE YEAR!

D. Cats can carry the ringworm fungus but not show signs of the disease. All cats in the household should be tested with a fungal culture. If positive, these cats should be treated along with the primary pet.

If I suspect your pet has Ringworm, I will properly prepare an area on the cat’s coat with isopropyl alcohol, and then pluck some hairs and place them in a special media for growth of the offending organism. Very often, highly contagious fungi will change the media color within 72 hours. Less infective fungi will take up to a week. All this information helps me to give you a prognosis as far as recovery rates, and success of treatment.

My preference in the treatment of Ringworm is the use of the reasonably inexpensive Griseofulvin®, given daily. There are newer designer drugs which are much more exciting to talk about, but they can be associated with more internal organ damage and are no more effective than the old tried-and-true. Griseofulvin must always be given with food. The veterinarian will need to be sure of the type of Griseofulvin needed.

Remember: Ringworm is contagious to you! If your pet has lesions like Ringworm, have it checked out, pronto!