Freshwater Disease Guide

Hemorrhage Septicemia (Aeromonas hydrophila)
Symptoms:
Bright red streaks on fins (caused by vascular inflammation due to systemic/bloodborne bacterial infection), patchy red discoloration around the body, pop-eye, protrusion of scales, distended abdomen, rapid breathing

Causes:
Gram negative motile rod bacteria. It is usually associated with poor water quality, stress and overpopulation. Transmission is done by contamination of water with diseased fish.

Treatment:
Broad spectrum antibiotics. Frequent water changes are necessary to improve water quality and allowing recovery of fish.

Fish Tuberculosis (Mycobacterium spp.)
Symptoms:
Emaciation, inflammation of the skin, exophthalmia (Pop-eye), ascites (Dropsy), open lesions, ulceration, sluggishness, bloated abdomen, fin rot, scale loss, skin discoloration, bent spines

Granulomas can be observed in vital organs when a necropsy is performed on the affected fish.

Causes:
Various pathogens. Positive diagnosis not possible outside the laboratory and microscopy.

According to Adrian Tappin, there are several species of Mycobacteriosis species found during further analysis of 42 samples taken from a home aquaria: Mycobacterium fortuitum, M. flavescens, M. chelonae, M. gordonae, M. terrae, M. triviale, M. diernhoferi, M. celatum, M. kansasii and M. intracellulare.

Under pathology examination, these bacteria are often found in apparently healthy rainbowfishes. Young rainbowfishes infected with mycobacteria often show no external signs. As they grow, the infection becomes more serious. However, once present in an aquarium, a 100% infection rate of the population is conceivable.

Treatment:
There is no known treatment against this disease. Destroy all afflicted fish and disinfect the whole aquarium.

More information can be found in Adrian Tappin's website "Home of the Rainbowfish".

Further information on all types of freshwater fish (not just goldfish) can be found here.
Mycobacterium in goldfish

Warning:
This can be transmitted as zoonosis called "fish tank granuloma" on hands with open wounds. Use gloves if reaching the tank with suspect animals.

Check this article by Dr. Barb for more details regarding the "fish tank granuloma".

Erythrodermatitis
Synonyms:
Red Sore Disease

Symptoms:
Lethargic, anorexic, emaciated, heavily ulcerated with bloody red sores

Causes:
Poor environment conditions can encourage bacteria of the Aeromonas genus to proliferate and infect fish. The bacteria itself is responsible for other bacterial diseases such as fin rot.

Erythrodermatitis for carps occur during summer and autumn. The disease takes a slow course. At first, the fish may appear to have a healthy impression but red stains appear in the next few weeks turning into ulcers that break open and the fish soon afterwards die with large open sores on the skin.

This disease has been confused with spring virosis as it appears as red stains the early stages. It can be assumed that this disease can be transmitted by blood-sucking parasites, a similar case that occurs with the spring virosis.

Treatment:
Terramycin, Romet-30, Sera Cyprinopur

Carp Pox
Symptoms:
Round or oval-shaped pale or pink elevations measuring from 5-10 mm appearing on the body surface of the affected fish

Causes:
Cold temperature can bring about the carp pox which is not a real pox but a herpes disease, which is not transmitted to humans.

Treatment:
In some cases, it has been known to return on winter season or when the temperature becomes cold and eventually disappears as the warm weather comes noting that this disease is caused by a coldwater virus. The fish, however, do not appear to be suffering very much from the infection even when heavily infested hence they will not die from the carp pox. They gradually recover when kept under the optimum conditions.

The disease is, however still a remnant of the organism and will break out every time the fish becomes weakened especially during the spring.

Acriflavine can also be used to treat for carp pox.

Body Fungus (Saprolegnia spp.)
Symptoms:
White cottony patches on the skin with long filaments that stand away

Symptoms must be differentiated from the false mouth fungus, Columnaris.

Causes:
Fungi are decomposing organisms that exist in every aquarium. The wound must always be treated immediately. If left untreated, fungal spores can attach themselves on the wounds and eventually harm the fish. They serve as a secondary infection to the wounds and open sores.

Treatment:
Methylene Blue, Jungle Fungus Guard, Mardel Maroxy

Glossatella (Heteropolaria colisarium)
Synonyms:
Apiosoma

Symptoms:
A furry coating forms after the mucous membrane has been injured. You can see many elongated protozoans on a short stalk with a strong magnifying glass.

Causes:
Damaged mucous membrane allowing protozoans to invade and expand on the lesions. They do not feed directly on the lesions but on the secondary bacteria and isolated cells of the destroyed tissue.

Treatment:
Sera Costapur, Formalin, Copper Sulfate

Costia (Ichthyobodo necatrix)
Synonyms:
The name was formerly Costia necatrix, however the name Costia is more familiar and nevertheless still use until today.

Also called "Blue Slime Disease" in reference to heavy secretion of mucous membrane.

Symptoms:
Gray or milky areas of skin, clamped and frayed fins, frequent flashing movements

Causes:
This is caused by external flagellates which are secondary parasites that will gradually appear if the fish succumbs to stress or severely weakened.

Treatment:
Hydrogen peroxide, Formalin, Copper Sulfate, Acriflavine, Sera Costapur, Sera Ectopur

Chilodonella
Symptoms:
Heavy breathing, flashing movements, clamped fins, overproduction of mucous membrane, lethargic movements, loss of appetite

Causes:
It is caused by the "heart-shaped" ciliated protozoan, Chilodonella itself.

Treatment:
Sera Costapur, Sera Omnisan, Malachite Green, Potassium Permanganate, Formalin, Copper Sulfate, salt baths

Tetrahymena
Symptoms:
Flashing movements, clamped fins, overproduction of mucous membrane, lethargic movements, loss of appetite

Causes:
It is caused by a teardrop-shaped ciliated protozoan that lives in organic debris on the bottom of the aquarium implying that this is not a parasite at all. In an overloaded aquarium, it is possible that this protozoan will proliferate massively due to water pollution noting that this protozoan lives in areas with very high organic loads.

Treatment:
Sera Costapur, Sera Mycopur, Sera Baktopur, Malachite Green, Potassium Permanganate, Formalin, Copper Sulfate, salt baths

Trichodina
Symptoms:
Lethargic movements, flashing and rubbing, reddening of certain areas due to rubbing out of sheer extreme irritation

Causes:
Another protozoan that is not actually a parasite and are characterized by their flying saucer shape. It does not feed on fish but use them as a means of transportation from one aquarium to another. Healthy fish is not usually bothered by a low number of protozoans however a big infestation of Trichodina brought by poor water quality and overcrowding can cause extreme irritation and eventually stress to the fish.

Treatment:
Sera Costapur, Sera Omnisan, Malachite Green, Potassium Permanganate, Formalin, Copper Sulfate, salt baths