Tuberculosis (Mycobacterium tuberculosis)

Mycobacterium tuberculosis or also commonly called Tuberculosis and Fish Tuberculosis (FT) is a free-living bacteria that not only can affect fish species but also can be transmitted to humans. Therefore, we highly recommend care when dealing with this disease and avoiding placing your hands inside of any of the water, touching the fish directly, or dealing with any of the fish's equipment without wearing gloves or other means of protection.


There are various ways in which tuberculosis can be detected and seen within infected fish and humans. A majority of the symptoms that the fish has, a human will have if they come into contact with this disease and do not use the correct protection to prevent themselves from getting it.

The first symptoms that the fish will display include becoming lethargic, having a hollow stomach area, coloration on the body starting to fade away, fins starting to fray or rot, scales might start to appear to be falling off and lastly signs of ulcers underneath the scales. Once the disease starts to fully spread inside of the fish include yellow or dark red bumps appearing under the body or eyes along with the fish starting to develop a bent spine.


A majority of fish species already carry this bacterium either within their bodies or through the food that they naturally eat. When the fish has no other weaknesses of their immune system due to good conditions and a proper diet, the bacteria will stay dormant. However, once the fish's immune system becomes weak the bacteria will reactivate and can start to infect not only the fish but any other fish that comes in contact with the infected fish. In a majority of environments, this bacterium is spread from fish bullying the weaker fish or attempting to eat its body once the infected fish dies, thereby now infected the healthy fish and turning them into a carrier of this bacteria.

Sadly, due to the way that this bacterium can stay alive in hosts that do not have a weak immune system, making sure to keep water conditions perfect, making sure to not overstock the setup with too many fish, and also to have the correct water temperature set is very important. Many have noted that the most common carriers of this disease are labyrinth fish due to the nature of how they are commonly bred in poor conditions while sharing water with all of their neighboring fish.

Treatment and Medication

Unfortunately, there is no known cure to this disease although many have stated that using a bacterial and fungus medication does slow down and can prevent death if given at the very early stages. A common treatment that many aquarists use once they see the starting symptoms of this disease is to make sure that the water conditions are kept near perfect and to also treat them with Kanamycin. The early stages include where the fish may be showing very little swelling, stop eating for days, have symptoms of other diseases, and even will be alone and not near or with any other inhabitants. There is no known documented proof such medicines do truly work once the second symptoms start showing.


Due to the way that this disease affects the inhabitants, the best prevention methods are to always make sure that you quarantine anything that you place inside of your water (this includes any plants, inhabitants, decorations, and more). Thus, when you do let them adjust to your water and you truly see how they are acting, eating and if they have any symptoms or signs, we will either start to get a better understanding if they are infected or learn about what possible other diseases they might have.