Tuberculosis (TB)

This page is part of our betta disease and illness section.

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What is Tuberculosis?

Before we get started we should mention that it’s quite rare for a betta to contract tuberculosis, so don’t panic if your betta starts exhibiting one of the symptoms that can be indicative of TB. The chances are it’s a different illness altogether and with the right treatment your betta will make a recovery.

Betta tuberculosis is a slow-blooming disease that a betta can have for up to 6 months before exhibiting any symptoms. Ultimately, the bacteria will attack the internal organs (especially liver and kidneys), causing organ failure. This is when the symptoms of TB will show – such as raised scales, bloated body – and will be swiftly followed by death.

This is the only fish disease known to be contagious to man, although the good news is it’s very hard to contract tuberculosis from a fish. Fish tuberculosis can be resident in water but has also been linked to live foods (researchers found cases of live foods infected by tuberculosis), and is mainly passed by ingestion (eating contaminated live food, or eating a dead fish that was a carrier, etc…)


If your betta is suffering from tuberculosis, its health will suddenly start to deteriorate. He or she may start losing weight, grow body deformities such as popeye, suffer from bloated gills and scales, red clamped gills, raised scales (otherwise known as pine-coning), fin and body rot, red patches on its body and grey lesions along its side.

The symptoms can really vary with tuberculosis — a betta can get some of them, none of them or all of them, but will die very soon after contraction if it is indeed tuberculosis that it’s suffering from. However, just because a betta has any of the symptoms shown above, it doesn’t necessarily mean it has tuberculosis — it could be symptomatic of a different illness as well.

    Possible Cures

    Sadly, there are no cures for betta tuberculosis. By the time you find out your fish has tuberculosis, it’s too late to take action. The only way to safeguard against tuberculosis is by feeding it reliably-sourced live food, although as we’ve mentioned it is rare for a betta to contract TB so you shouldn’t worry too much. Live food that has been frozen is a good substitute if you can’t get non-frozen live food. Live microworms and vinegar eel are also fine as they are not known to carry tuberculosis. See our guide on betta food for more information.

    You should also buy your fish from reliable suppliers that you know stock healthy fish, especially if you are adding more than one fish to an aquarium. All it takes is for one fish infected with TB to be added to the aquarium and it will likely spread to them all.