Common Names: Mycobacteriosis
Piscine tuberculosis
Fish TB
Mycobacterium fortuitum (freshwater strain)
Mycobacterium marinum (marine strain)
Fish Leprosy
Salinity: Freshwater
Description: This disease is capable via different strains, to infect both fish living in any salinity. This is a tenacious infection capable of surviving outside of a host body for several week, Quarantine times for mycobacterium may need to be in excess of two months. The bacteria is usually ingested, but when present in high concentration in aquaria it is capable of infecting a fish via minor wounds. It can affect all fish species, although resistances vary. Fish like rainbowfish are especially vulnerable, and their sparring behaviour supports the bacterias' spread. Mycobacterium is hugely variable in its effects on fish physiononomy, form causing warping in the spine in fish infected from a young age still in developmental growth stages, through to skin lesions, and general debilitation. Depending on the location of internal lesions the symptoms can even be neurological, including tremors, shaking and circling through to abnormal agression and waning behaviours. Lesions in the kidneys, heart, lungs and liver will all produce symptoms synonymous with those organs. Dropsy is not an uncommon complication. Mycobacterium are a recognised zoonotic (meaning they can infect humans) and often infect people working in the fishing and food preparation industry. In aquarists the infection may enter the body through minor wounds and via the mouth, usually from starting syphons orally, or eating food prepared without washing hands after contact with aquarium water. In those situations symptoms can be skin lesions and medical help should be sought immediately. Untreated it can cause debilitation in humns as well as piscines. For those with paludaria involving fish to be kept with reptiles and amphibians it should also be noted that all of these animal groups can be infected, and may transmit the bacteria to each other. This bacteria easily crosses species barriers in these groups.
Symptoms: Spots
Treatment: Metrionidazole administered orally via medications like jungle labs antiparasite formula are effective. Pure liquid suspensions of metronidazole are available either from veterinary practises, or chemists in an orally administerable form. The brandname FLAGYL is probably the most common supplier of metronidazole worldwide. Kanymycin has also be suggested as an effective drug for treatment.

Low stocking levels and the avoidance of close contact can significantly reduce transmission rates.In the absence of effective treatment a euthanasia policy should be adopted and safe disposal of corpses observed. Fish may suffer greatly in advanced stages of infection. Severity of symptoms depends on the level of bacteria in the body and the damage they do according to area. In heavily poulated aquaria, the severity will accelerate due to constant reinfection.
Comments: Because of the huge amount of symptopms associated with this complaint , and its sometimes slow development (some fish dont show symptoms for years!)conclusive diagnosis in the home is very difficult. In community settings where massive numbers of fish may be lost, it may be worth sacrificing one afflicted specimen to a vet for testing and a bacteriology report. It is a common emergent problem in long established aquaria , and often a source of "mystery" fish deaths.
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Submitted By: longhairedgit
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