While there are many different diseases that bettas, and other fish, can suffer from there are also a number of medications readily available in pet stores to treat your fish. 

Use Medications With Caution

Though in North America medications for fish are sold by pet stores, these are still veterinary grade drugs and should be treated with the same respect. Many are the exact same drugs that are only available for cats or dogs (or humans) by prescription.


Hazards of common drugs used in aquariums include:

  • Physical stress to fish receiving medication
    • Many medications available for fish are very strong/harsh
    • For example, the antibiotic Kanamycin can cause liver damage while being administered, and may prove too strong for extremely ill or weak fish to handle
  • Carcinogens
    • Some medications marketed for fish are known cancer-caushing agents!
    • Examples: Formalin and Malachite Green
    • Alternative medications are often available to treat the same disease, and should always be chosen when possible
  • Antibiotic resistance
    • Excessive and/or inappropriate use of antibiotics allows some harmful bacteria to develop immunity to these antibiotics
    • This is the same issue facing human healthcare - for example, the Do Bugs Need Drugs? campaign.
  • Destruction of natural, beneficial filter bacteria
    • Many antibiotics and medications will kill not only the bacteria that is infecting your fish, but also the bacteria that you worked so hard to cultivate in the NITROGEN CYCLE